Evaluating the suitability of supra-POpeak verification trials after ramp-incremental exercise to confirm the attainment of maximum O2 uptake.
Abstract During exhaustive ramp-incremental cycling tests, the incidence of O2 uptake (V̇O2) plateaus is low. To verify the attainment of maximum V̇O2 (V̇O2max), it is recommended that a trial at a power output (PO) corresponding to 110% of the ramp-derived peak (POpeak) is performed. It remains unclear whether verification trials set at this PO can be tolerated for long enough to allow attainment of V̇O2max. Eleven recreationally-trained individuals performed five ramp tests of varying slope (5, 10, 15, 25, 30 W·min-1), each followed, in series, by two verification trials: the 1st at 110%POpeak of the ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 22, 2020 Category: Physiology Authors: Iannetta D, Azevedo RA, Ingram CP, Keir DA, Murias JM Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

The role of TASK-2 channels in CO2 sensing in zebrafish (Danio rerio).
Abstract Peripheral chemosensitivity in fishes is thought to be mediated by serotonin-enriched neuroepithelial cells (NECs) that are localised to the gills of adults and the integument of larvae. In adult zebrafish (Danio rerio), branchial NECs are presumed to mediate the cardiorespiratory reflexes associated with hypoxia or hypercapnia whereas in larvae, there is indirect evidence linking cutaneous NECs to hypoxic hyperventilation and hypercapnic tachycardia. No study yet has examined the ventilatory response of larval zebrafish to hypercapnia and regardless of developmental stage, the signalling pathways involve...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 22, 2020 Category: Physiology Authors: Koudrina N, Perry SF, Gilmour KM Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Impact of age and sex on neural cardiovascular responsiveness to cold pressor test in humans.
Abstract Prior longitudinal work suggests that blood pressure (BP) reactivity to the cold pressor test (CPT) helps predict hypertension, yet the impact of age and sex on hemodynamic and neural responsiveness to CPT remain equivocal. Forty-three young (21±1yrs, mean±SEM) men (YM, n=20) and women (YW, n=23), and 16 older (60±1yrs) men (OM, n=9) and women (OW, n=7), participated in an experimental visit where continuous BP (finger plethysmography) and muscle sympathetic nerve activity (MSNA; microneurography) were recorded during a 3-5min baseline and 2-min CPT. Baseline mean arterial pressure (M...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 22, 2020 Category: Physiology Authors: Keller-Ross ML, Cunningham HA, Carter JR Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Age-Related Changes in Isolated Mouse Skeletal Muscle Function are Dependent on Sex, Muscle & Contractility Mode.
CONCLUSION: Our findings show that the loss of muscle quality precedes the loss of absolute performance as CD-1 mice age, with the greatest effect seen in male soleus, and in most instances without muscle atrophy or an alteration in MHC isoforms. PMID: 32697655 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 22, 2020 Category: Physiology Authors: Hill C, James RS, Cox VM, Seebacher F, Tallis J Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Chronically Elevated Norepinephrine Concentrations Lower Glucose Uptake in Fetal Sheep.
Abstract Fetal conditions associated with placental insufficiency and intrauterine growth restriction (IUGR) chronically elevate plasma norepinephrine (NE) concentrations. Our objective was to evaluate the effects of chronically elevated NE on insulin-stimulated glucose metabolism in normally grown, non-IUGR fetal sheep, which are independent of other IUGR-related reductions in nutrients and oxygen availability. Following surgical placement of catheters, near-term fetuses receive either a saline (control) or NE intravenous infusion with controlled euglycemia. In NE fetuses, plasma NE concentrations were 5.5-fold g...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 15, 2020 Category: Physiology Authors: Davis MA, Camacho LE, Anderson MJ, Steffens NR, Pendleton AL, Kelly AC, Limesand SW Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Fas Ligand neutralization attenuates hypertension, endothelin-1 and placental inflammation in an animal model of HELLP Syndrome.
CONCLUSIONS: Neutralization of FasL is associated with decreased MAP, improvement in placental inflammation and endothelial damage in a model of HELLP syndrome. PMID: 32640833 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 8, 2020 Category: Physiology Authors: Gibbens J, Spencer SK, Solis L, Bowles T, Kyle PB, Szczepanski J, Dumas JP, Robinson R, Wallace K Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Sex differences and the effects of intrauterine hypoxia on growth and in vivo heart function of fetal guinea pigs.
CONCLUSIONS: Early and late onset HPX induce placental insufficiency, fetal growth restriction, and increase diastolic filling depending on the sex, with female fetuses having a greater capacity than males to compensate to intrauterine hypoxia. PMID: 32639864 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 8, 2020 Category: Physiology Authors: Thompson LP, Turan S, Aberdeen GW Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Reply to "Letter to the Editor: Imaging Transcranial Doppler Ultrasound: is it giving us an accurate picture of cerebral hemodynamics?"
Reply to "Letter to the Editor: Imaging Transcranial Doppler Ultrasound: is it giving us an accurate picture of cerebral hemodynamics?" Am J Physiol Regul Integr Comp Physiol. 2020 Jul 01;319(1):R81 Authors: Jarrett CL, Richardson RS PMID: 32598166 [PubMed - in process] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 1, 2020 Category: Physiology Authors: Jarrett CL, Richardson RS Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Letter to the Editor: Imaging Transcranial Doppler Ultrasound: is it giving us an accurate picture of cerebral hemodynamics?
PMID: 32598167 [PubMed - in process] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 1, 2020 Category: Physiology Authors: Thomas KN, Gibbons TD, Necas M Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Cardiovascular and metabolic responses to passive hypoxic conditioning in overweight and mildly obese individuals.
ges S Abstract BACKGROUND: While severe intermittent hypoxia (IH) is well known to induce deleterious cardiometabolic consequences, moderate IH may induce positive effects in obese individuals. The present study aimed to evaluate the effect of two hypoxic conditioning programs on cardiovascular and metabolic health status of overweight or obese individuals. METHODS: In this randomized single-blind controlled study, 35 subjects (54±9.3yr, 31.7±3.5kg·m-2) were randomized into three 8-week interventions (three 1-hour sessions per week): sustained hypoxia (SH), arterial oxygen saturation (SpO...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 1, 2020 Category: Physiology Authors: Chacaroun S, Borowik A, Doutreleau S, Belaidi E, Wuyam B, Tamisier R, Pépin JL, Flore P, Verges S Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Untangling lifespan and body mass discrepancies in canids: Phylogenetic comparison of oxidative stress in blood from domestic dogs and wild canids.
Abstract Canids are a morphological and physiological diverse group of animals, with the most diversity found within one species, the domestic dog. Underlying the observed morphological differences must be cellular-level differences that could lead to elucidating aging rates and lifespan disparities between wild and domestic canids. Furthermore, small breed dogs live significantly longer lives than large breed dogs while having higher mass-specific metabolic rates and faster growth rates. At the cell level, a clear mechanism underlying whole-animal traits has not been fully elucidated, though, oxidative stress has...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 1, 2020 Category: Physiology Authors: Jimenez AG, Downs CJ Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Intrathecal injection of Brilliant Blue G, a P2X7 antagonist, attenuates the exercise pressor reflex in rats.
Abstract Purinergic 2X receptors (P2X) on the endings of group III and IV afferents play a role in evoking the exercise pressor reflex. Particular attention has been paid to P2X3 receptors because their blockade in the periphery attenuated this reflex. In contrast, nothing is known about the role played by P2X receptors in the spinal cord in evoking the exercise pressor reflex in rats. P2X7 receptors, in particular, may be especially important in this regard because they are found in abundance on spinal glial cells and may communicate with neurons to effect reflexes controlling cardiovascular function. Consequentl...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 1, 2020 Category: Physiology Authors: Estrada JA, Ducrocq GP, Kim JS, Kaufman MP Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Correlation between intermediary metabolism, Hsp gene expression and oxidative stress related proteins in long-term thermal stressed Mytilus galloprovincialis.
Abstract Long-term exposure of Mytilus galloprovincialis to temperatures beyond 26oC triggers mussels' mortality. The present study aimed to integratively illustrate the correlation between intermediary metabolism, Hsp gene expression and oxidative stress related proteins in long-term thermally stressed Mytilus galloprovincialis and whether they are affected by thermal stress' magnitude and duration. We accordingly evaluated the gene expression profiles, in the posterior adductor muscle (PAM) and the mantle, concerning hsp70 and hsp90, and the antioxidant defense indicators Mn-SOD, Cu/Zn-SOD, catalase, glutathione...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - July 1, 2020 Category: Physiology Authors: Feidantsis K, Giantsis IA, Vratsistas A, Makri S, Pappa AZ, Drosopoulou E, Anestis A, Mavridou E, Exadactylos A, Vafidis D, Michaelidis B Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Corrigendum.
Authors: PMID: 32568594 [PubMed - in process] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - June 24, 2020 Category: Physiology Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Compensatory eating behaviors in male and female rats in response to exercise training.
Abstract Exercise is often used as a strategy for weight loss maintenance. In preclinical models, we have shown that exercise may be beneficial because it counters the biological drive to regain weight. However, our studies have demonstrated sex differences in the response to exercise in this context. In the present study, we sought to better understand why females and males exhibit different compensatory food eating behaviors in response to regular exercise. Using a forced treadmill exercise paradigm, we measured weight gain, energy expenditure, food intake in real time, and the anorectic effects of leptin. The 4...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - June 17, 2020 Category: Physiology Authors: Foright RM, Johnson GC, Kahn D, Charleston CA, Presby DM, Bouchet CA, Wellberg EA, Sherk VD, Jackman MR, Greenwood BN, MacLean PS Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Circulating catecholamines partially regulate T wave morphology but not heart rate variability during repeated umbilical cord occlusions in fetal sheep.
CONCLUSIONS: These data demonstrate that circulating catecholamines do not contribute to FHRV during labor-like hypoxemia. Furthermore, circulating catecholamines did not contribute to the major rise in T/QRS ratio during labor-like hypoxemia but may regulate T/QRS ratio between brief hypoxemia. PMID: 32491938 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - June 3, 2020 Category: Physiology Authors: Lear CA, Beacom MJ, Kasai M, Westgate JA, Galinsky R, Magawa S, Miyagi E, Ikeda T, Bennet L, Gunn AJ Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Effects of Electroacupuncture on Stress-induced Gastric Dysrhythmia and Mechanisms Involving Autonomic and Central Nervous Systems in Functional Dyspepsia.
Abstract BACKGROUND: Electroacupuncture (EA) is widely used as an effective method to treat stress-related disorders. However, its mechanisms remain largely unknown. The aim of this study was to investigate the effects and mechanisms of EA on gastric slow wave dysrhythmia and c-Fos expression in the nucleus tractus solitarius (NTS) induced by stress in a rodent model of functional dyspepsia (FD). METHODS: Rats in neonatal stage were treated using intragastric iodoacetamide. Eight weeks later, the rats were implanted with electrodes in the stomach for the measurement of gastric slow waves (GSW) and electrodes ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - June 3, 2020 Category: Physiology Authors: Zhang S, Liu Y, Li S, Ye F, Foreman RD, Chen JD Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Sex steroid hormone-dependent plasticity of brainstem autonomic circuits.
Abstract In the central nervous system (CNS), nuclei of the brainstem play a critical role in the integration of peripheral sensory information and the regulation of autonomic output in mammalian physiology. The nucleus tractus solitarius (NTS) of the brainstem acts as a relay center that receives peripheral sensory input from vagal afferents of the nodose ganglia, integrates information from within the brainstem and higher central centers, then transmits autonomic efferent output through downstream premotor nuclei, such as the nucleus ambiguus (NA), the dorsal motor nucleus of the vagus (DMV), and the rostral ven...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - June 3, 2020 Category: Physiology Authors: Littlejohn EL, Fedorchak S, Boychuk CR Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Lung injury in brain ischemia/reperfusion is exacerbated by mechanical ventilation with moderate tidal volume in rat.
CONCLUSION: Brain ischemia/reperfusion leads to pulmonary capillary endothelial damage and the impairment of gas exchange in the alveolar-capillary barrier, which is exacerbated by mechanical ventilation with moderate tidal volume partially linked to inflammatory reactions. PMID: 32459970 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 27, 2020 Category: Physiology Authors: Naseh M, Dehghanian A, Keshtgar S, Ketabchi F Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Sugar uptake, metabolism, and chloride secretion in the rectal gland of the spiny dogfish Squalus acanthias.
Abstract The rectal gland of the spiny dogfish secretes an isosmotic salt solution against an electrochemical gradient requiring the expenditure of energy. Isolated rectal glands perfused without glucose secrete salt at about thirty percent of glands perfused with 5 mM glucose. Gradually reducing the glucose concentration is associated with a progressive decrease in chloride secretion. The apparent Km for glucose dependent chloride secretion is 2 mM. Phloretin and cytochalasin B do not inhibit the secretion of chloride by the perfused rectal glands. Phloridzin or a-methyl-D-glucoside both inhibit the secretion of ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 27, 2020 Category: Physiology Authors: Kinne R, Spokes KC, Silva P Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Early accentuated muscle hypertrophy is strongly associated with myonuclear accretion.
alo R Abstract The current study explored whether the marked hypertrophic response noted with a short-term unilateral concurrent exercise paradigm was associated with more prominent changes in myonuclei accretion, ribosome biogenesis and capillarization compared to resistance exercise alone (RE). Ten men (age 25±4yr) performed aerobic and resistance exercise (AE+RE) for one leg, while the other leg did RE. Muscle biopsies were obtained before and after 5 weeks of training and subjected to fiber-type specific immunohistochemical analysis, and quantification of total RNA content and mRNA/rRNA transcript abund...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 20, 2020 Category: Physiology Authors: Lundberg TR, Martínez-Aranda LM, Sanz G, Hansson B, von Walden F, Tesch PA, Fernandez-Gonzalo R Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Effect of 8 days of exercise-heat acclimation on aerobic exercise performance of men in hypobaric hypoxia.
This study assessed whether EHA can alter time-trial performance and/or incidence of acute mountain sickness (AMS) during HH exposure. Thirteen sea level (SL) resident men (SL VO2peak: 3.19 ± 0.43 l·min-1) completed steady-state exercise followed by a 15-min cycle time-trial and assessment of AMS before (HH1; 3,500 m) and after (HH2) an 8-day EHA protocol (120 min; 5 km·hr-1; 2% incline; 40°C and 40% RH). EHA induced lower heart rate (HR) and core temperature, and plasma volume expansion. Time-trial performance was not different between HH1 and HH2 after 2-hr(106.3±23.8 vs 101.4±23.0 ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 20, 2020 Category: Physiology Authors: Salgado RM, Coffman KE, Bradbury KE, Mitchell KM, Yurkevicius BR, Luippold AJ, Mayer TA, Charkoudian N, Alba BK, Fulco CS, Kenefick RW Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Ontogeny of carnitine biosynthesis in Sus scrofa domesticus, inferred from γ-butyrobetaine hydroxylase (dioxygenase) activity and substrate inhibition.
Ontogeny of carnitine biosynthesis in Sus scrofa domesticus, inferred from γ-butyrobetaine hydroxylase (dioxygenase) activity and substrate inhibition. Am J Physiol Regul Integr Comp Physiol. 2020 May 20;: Authors: Xi L, Peffer PL, Woodworth JC, Odle J Abstract Gamma-butyrobetaine hydroxylase (γ-BBH) is the last limiting enzyme of the L-carnitine biosynthesis pathway and plays an important role in catalyzing the hydroxylation of γ-butyrobetaine (γ-BB) to L-carnitine. To study the developmental effect of substrate on the enzyme's specific activity, kinetics of γ-BBH were m...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 20, 2020 Category: Physiology Authors: Xi L, Peffer PL, Woodworth JC, Odle J Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

H2S stimulated bioenergetics in chicken erythrocytes and the underlying mechanism.
In conclusion, H2S may regulate cellular bioenergetics as well as cell survival of chicken erythrocytes, in which the functionality of electron transport chain is involved. H2S may have different regulatory roles and mechanisms in bioenergetics of mammalian and bird cells. PMID: 32432916 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 20, 2020 Category: Physiology Authors: Jin Z, Zhang Q, Wondimu E, Verma R, Fu M, Shuang T, Arif HM, Wu L, Wang R Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

2019 Water and Electrolyte Homeostasis Section Trainee Award: "Influences of Environmental Factors During Preeclampsia".
2019 Water and Electrolyte Homeostasis Section Trainee Award: "Influences of Environmental Factors During Preeclampsia". Am J Physiol Regul Integr Comp Physiol. 2020 May 20;: Authors: Dasinger JH, Abais-Battad JM, Mattson DL Abstract Preeclampsia is a pregnancy-specific disorder that impacts 5-8% of pregnancies and has long-term cardiovascular and metabolic implications for both mother and fetus. The mechanisms are unclear; however, it is believed that preeclampsia is characterized by abnormal vascularization during placentation resulting in the manifestation of clinical signs such as hypert...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 20, 2020 Category: Physiology Authors: Dasinger JH, Abais-Battad JM, Mattson DL Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

The combined effects of moderate exercise and short-term fasting on markers of immune function in healthy human subjects.
This study aimed to investigate the effects of a short-term (36h) fasting period combined with an acute bout of exercise on markers of immune function and inflammation in healthy human subjects. Fourteen moderately trained male subjects (aged 19-39 years) participated in a 36 hrs Fasting-Trial (FA-T) followed by an acute bout of moderate exercise (60% VO2max). After one week, the same subjects, as their own control, participated in a Non-Fasting-Trial (NFA-T), in which they performed an exercise trial of the same duration and intensity. Blood samples were taken before, immediately and one hour after each exercise bout and ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 13, 2020 Category: Physiology Authors: Mooren FC, Krueger K, Ringseis R, Eder K, Liebisch G, Conrad K, Alack K, Hajizadeh Maleki B Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Imaging Transcranial Doppler Ultrasound to Measure Middle Cerebral Artery Blood Flow: The Importance of Measuring Vessel Diameter.
Abstract Cerebral blood flow (CBF) is commonly inferred from blood velocity measurements in the middle cerebral artery (MCA), using, non-imaging, transcranial Doppler ultrasound (TCD). However, both blood velocity and vessel diameter are critical components required to accurately determine blood flow, and there is mounting evidence that the MCA is vasoactive. Therefore, the aim of this study was to employ imaging TCD (ITCD), utilizing color flow images and pulse wave velocity, as a novel approach to measure both MCA diameter and blood velocity to accurately quantify changes in MCA blood flow. ITCD was performed at...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 13, 2020 Category: Physiology Authors: Jarrett CL, Shields KL, Broxterman RM, Hydren JR, Park SH, Gifford JR, Richardson RS Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Aerobic Exercise Offsets Endothelial Dysfunction Induced by Repetitive Consumption of Sugar-Sweetened Beverages in Young Healthy Men.
Abstract Consumption of a single, sugar-sweetened beverage (SSB) impairs vascular endothelial function. Regular aerobic exercise improves endothelium-dependent vasodilation; however, it's unknown if these beneficial-effects persist with frequent SSB consumption. Therefore, the purpose of this study was two-fold; we studied the effects of repetitive SSB consumption (75g D-glucose, 3x/day) for one week (Glu, n=13, 23±4yrs, 23.5±3.4kg/m2) on endothelium-dependent vasodilation (FMD). Then, in a separate cohort, we investigated if 45min of moderate-intensity aerobic exercise on five separate days offset t...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 13, 2020 Category: Physiology Authors: Bock JM, Iwamoto E, Horak JG, Feider AJ, Hanada S, Casey DP Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Healthy active older adults have enhanced K+ channel-dependent endothelial vasodilatory mechanisms.
CONCLUSIONS: Healthy older adults have enhanced K+ channel-dependent endothelial vasodilatory mechanisms, suggesting increased responsiveness to EDHFs with age. PMID: 32401629 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 13, 2020 Category: Physiology Authors: Serviente C, Berry CW, Kenney WL, Alexander LM Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Paternal deficiency of complement component C1q leads to a preeclampsia-like pregnancy in wild-type female mice and vascular adaptations postpartum.
In conclusion, the ♀ C57BL/6J x ♂ C57BL/6J C1q-/- model recapitulates many aspects of the human preeclampsia syndrome in a low-risk, wild-type female mouse. The pregnancy-specific phenotype results in systemic maternal endothelial-dependent and -independent vascular dysfunction that persists postpartum. PMID: 32374620 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 6, 2020 Category: Physiology Authors: Sutton EF, Gemmel M, Brands J, Gallaher MJ, Powers RW Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

AJP-RIC: Looking Towards the Future.
PMID: 32374621 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - May 6, 2020 Category: Physiology Authors: Yosten GLC Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Maternal Endothelial Function, Circulating Endothelial Cells and Endothelial Progenitor Cells in Pregnancies Conceived With or Without In Vitro Fertilization.
Abstract In women who conceived with or without assisted reproduction, we evaluated endothelial function by EndoPATTM [Reactive Hyperemia Index (RHI)], circulating numbers of endothelial cells (CEC) and endothelial progenitor cells (EPC), and their function before, during and after pregnancy. IVF pregnancies were stratified by method of conception and corpus luteum (CL) number-controlled ovarian stimulation (>1 CL) or programmed (0 CL) cycles, and spontaneous, singleton pregnancies (1 CL). We observed: (1) comparable gestational decline of RHI in the three participant groups secondary to gestational rise of bas...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 29, 2020 Category: Physiology Authors: Conrad KP, Lingis M, Sautina L, Li S, Chi YY, Qiu Y, Li M, Williams RS, Rhoton-Vlasak A, Segal MS Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Upgrading hypertension treatment.
PMID: 32348155 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 29, 2020 Category: Physiology Authors: Goetze JP, Hansen LH, Terzic D, Mark PD Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Circadian clock genes and respiratory neuroplasticity genes oscillate in the phrenic motor system.
Abstract Circadian rhythms are endogenous and entrainable daily patterns of physiology and behavior. Molecular mechanisms underlie circadian rhythms, characterized by an ~24-hour pattern of gene expression of core clock genes. Although it has long been known that breathing exhibits circadian rhythms, little is known concerning clock gene expression in any element of the neuromuscular system controlling breathing. Further, we know little concerning gene expression necessary for specific respiratory functions, such as phrenic motor plasticity. Thus, we tested the hypotheses that transcripts for clock genes (Bmal1, C...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 29, 2020 Category: Physiology Authors: Kelly MN, Smith DN, Sunshine MD, Ross A, Zhang X, Gumz ML, Esser KA, Mitchell GS Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Muscle Metaboreflex-Induced Increases in Effective Arterial Elastance: Effect of Heart Failure.
Abstract Dynamic exercise elicits robust increases in sympathetic activity in part due to muscle metaboreflex activation (MMA) - a pressor response triggered by activation of skeletal muscle afferents. MMA during dynamic exercise increases arterial pressure by increasing cardiac output via increases in heart rate, ventricular contractility, and central blood volume mobilization. In heart failure ventricular function is compromised and MMA elicits peripheral vasoconstriction. Ventricular-vascular coupling reflects the efficiency of energy transfer from the left ventricle to the systemic circulation and is calculate...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 29, 2020 Category: Physiology Authors: Mannozzi J, Kaur J, Spranger MD, Al-Hassan MH, Lessanework B, Alvarez A, Chung CS, O'Leary DS Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Cx30.2 deletion causes imbalances in testicular Cx43, Cx46 and Cx50 and insulin receptors. Reciprocally, diabetes/obesity alters Cx30.2 in mouse testis.
Abstract Cx30.2 protein content and localisation were assessed during development. An account of Cx30.2, Cx43, Cx46 and Cx50, and insulin receptor (IR) responses to Cx30.2, Cx46 or Cx50 deficiency in mouse interstitial tissue- (ITf) and seminiferous tubule-enriched fractions (STf) is given. The impact of high glucose/insulin on Cx30.2 was investigated in spontaneously diabetic and obese db/db and ob/ob mouse testis and anterior pituitary (AP). Cx30.2 labelled contacts in vascular endothelial and Leydig cells and Sertoli cell junctions in stage V-VII. Cx30.2 expression is regulated differently in the interstitium a...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 29, 2020 Category: Physiology Authors: Pelletier RM, Layeghkhavidaki H, Kumar NM, Vitale ML Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Interleukin-17 Signaling Mediates Cytolytic Natural Killer Cell Activation in Response to Placental Ischemia.
Abstract TH17s, IL-17, and cytolytic natural killer cells (cNKs) are increased in preeclampsia and contribute to the hypertension, inflammation, and fetal growth restriction that occurs in response to placental ischemia in the Reduced Uterine Perfusion Pressure (RUPP) rat model of preeclampsia. As IL-17 stimulates NK cytotoxicity in vitro, we tested the hypothesis that IL-17 inhibition in RUPP rats would decrease cNK activation as a mechanism to improve maternal and fetal outcomes. On gestation day (GD)14, rats undergoing RUPP received a mini-osmotic pump infusing IL-17RC (100 pg/day), a soluble IL-17 receptor (RU...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 22, 2020 Category: Physiology Authors: Travis OK, White D, Baik CH, Giachelli C, Thompson W, Stubbs C, Greer M, Lemon JP, Williams JM, Cornelius DC Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Characteristics of Myoelectrical Activities along the Small Intestine and Their Responses to Test Meals of Different Glycemic Index in Rats.
CONCLUSIONS: In addition to the well-known frequency gradient, there is also a gradual decrease in the DP and spikes along the small intestine in the fasting state. Glucose and hyperglycemic meals inhibit myoelectrical activities in the proximal small intestine, but result in enhanced but more dysrhythmic intestinal myoelectrical activities. There is a significant negative correlation between the normality of intestinal slow-waves and blood glucose. PMID: 32320266 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 22, 2020 Category: Physiology Authors: Liu Y, Ye F, Zhang S, Li S, Chen JD Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Thrombin action on astrocytes in the hindbrain of the rat disrupts glycemic and respiratory control.
Abstract Severe trauma can produce a post-injury "metabolic self-destruction" characterized by catabolic metabolism and hyperglycemia. The severity of the hyperglycemia is highly correlated with post-trauma morbidity and mortality. Although no mechanism has been posited to connect severe trauma with a loss of autonomic control over metabolism, traumatic injury causes other failures of autonomic function, notably, gastric stasis and ulceration ("Cushing's Ulcer") which has been connected with the generation of thrombin. Our previous studies established that proteinase-activated receptors (PAR1; ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 22, 2020 Category: Physiology Authors: Rogers RC, Hasser EM, Hermann GE Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Peroxiredoxin 1 plays a primary role in protecting pancreatic ß-cells from hydrogen peroxide and peroxynitrite.
Peroxiredoxin 1 plays a primary role in protecting pancreatic ß-cells from hydrogen peroxide and peroxynitrite. Am J Physiol Regul Integr Comp Physiol. 2020 Apr 15;: Authors: Stancill JS, Happ JT, Broniowska KA, Hogg N, Corbett JA Abstract Both reactive nitrogen and oxygen species (RNS and ROS) such as nitric oxide, peroxynitrite, and hydrogen peroxide have been implicated as mediators of pancreatic ß-cell damage during the pathogenesis of autoimmune diabetes. While ß-cells are thought to be vulnerable to oxidative damage due to reportedly low levels of antioxidant enzymes such as ca...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 15, 2020 Category: Physiology Authors: Stancill JS, Happ JT, Broniowska KA, Hogg N, Corbett JA Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

A Novel Regulator of Thirst Behavior: Phoenixin.
Abstract There are examples of physiologic conditions under which thirst is inappropriately exaggerated, and the mechanisms for these paradoxical ingestive behaviors remain unknown. We are interested in thirst mechanisms across the female life cycle and have identified a novel mechanism through which ingestive behavior may be activated. We discovered a previously unrecognized, endogenous hypothalamic peptide, phoenixin (PNX, 21), identified physiologically relevant actions of the peptide in brain and pituitary gland to control reproductive hormone secretion in female rodents (17, 21) and in the process identified ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 15, 2020 Category: Physiology Authors: Haddock CJ, Almeida-Pereira G, Stein LM, Yosten GLC, Samson WK Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Ghrelin signaling contributes to fasting-induced attenuation of hindbrain neural activation and hypophagic responses to systemic cholecystokinin in rats.
Abstract In rats, overnight fasting reduces the ability of systemic cholecystokinin-8 (CCK) to suppress food intake and to activate cFos in the caudal nucleus of the solitary tract (cNTS), specifically within glucagon-like peptide-1 (GLP-1) and noradrenergic (NA) neurons of the A2 cell group. Systemic CCK increases vagal sensory signaling to the cNTS, an effect which is amplified by leptin and reduced by ghrelin. Since fasting reduces plasma leptin and increases plasma ghrelin levels, we hypothesized that peripheral leptin administration and/or antagonism of ghrelin receptors in fasted rats would rescue the abilit...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 15, 2020 Category: Physiology Authors: Maniscalco JW, Edwards CM, Rinaman L Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Sympathetic neural recruitment strategies following acute intermittent hypoxia in humans.
We examined the effect of acute intermittent hypoxia (IH) on sympathetic neural firing patterns and the role of the carotid chemoreceptors. We hypothesized exposure to acute IH would increase muscle sympathetic nerve activity (MSNA) via an increase in action potential (AP) discharge rates and within-burst firing. We further hypothesized any change in discharge patterns would be attenuated during acute chemoreceptor deactivation (hyperoxia). METHODS: MSNA (microneurography) was assessed in 17 healthy adults (11M/6F; 31±1 yrs) during normoxic rest prior to and following 30-min of experimental IH. Prior to and fol...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 8, 2020 Category: Physiology Authors: Ott EP, Jacob DW, Baker SE, Holbein WW, Scruggs ZM, Shoemaker JK, Limberg JK Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Human thermoregulation during prolonged exposure to warm and extremely humid environments expected to occur in disabled submarine scenarios.
Abstract Military and civilian emergency situations often involve prolonged exposures to warm and very humid environments. We tested the hypothesis that increases in core temperature and body fluid losses during prolonged exposure to warm and very humid environments are dependent on dry bulb temperature. On three occasions, fifteen healthy males (23±3 y) sat in 32.1±0.1°C, 33.1±0.2°C or 35.0±0.1°C, and 95±2% relative humidity normobaric environments for 8 h. Core temperature (telemetry pill) and percent change in body weight, an index of changes in total body water oc...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 1, 2020 Category: Physiology Authors: Schlader ZJ, Johnson BD, Pryor RR, Stooks J, Clemency BM, Hostler D Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Experimental oxygen concentration influences rates of mitochondrial hydrogen peroxide release from cardiac and skeletal muscle preparations.
Abstract Mitochondria utilize the majority of oxygen (O2) consumed by aerobic organisms as the final electron acceptor for oxidative phosphorylation (OXPHOS), but also to generate reactive oxygen species (mtROS) that participate in cell signaling, physiological hormesis and disease pathogenesis. Simultaneous monitoring of mtROS production and oxygen consumption (JO2) from tissue mitochondrial preparations is an attractive investigative approach, but introduces dynamic changes in media O2 concentration ([O2]) that can confound experimental results and interpretation. We utilized high-resolution fluoro-respirometry ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - April 1, 2020 Category: Physiology Authors: Li Puma LC, Hedges M, Heckman JM, Mathias AB, Engstrom MR, Brown AB, Chicco AJ Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Phoenixin-20 (PNX-20) Suppresses Food Intake, Modulates Glucoregulatory Enzymes, and Enhances Glycolysis in Zebrafish.
Abstract Phoenixin is a 20 amino acid peptide (PNX-20) cleaved from the small integral membrane protein 20 (SMIM20), with multiple biological roles in mammals. However, its role in non-mammalian vertebrates is poorly understood. This research aimed to determine whether PNX-20 influences feeding and metabolism in zebrafish. The mRNAs encoding SMIM20 and its putative receptor, super conserved receptor expressed in brain 3 (SREB3), are present in both central and peripheral tissues of zebrafish. Immunohistochemical analysis confirmed the presence of PNX-like immunoreactivity in the gut and zebrafish liver (ZFL) cell ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - March 25, 2020 Category: Physiology Authors: Rajeswari JJ, Blanco AM, Unniappan S Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Relationship between impaired parasympathetic vasodilation and hyposalivation in parotid glands associated with type 2 diabetes mellitus.
We examined the relationship between hemodynamics in the three major salivary glands and salivary secretion in urethane-anesthetized and sympathectomized type 2 diabetic and nondiabetic rats via laser speckle imaging and by collecting saliva. Lingual nerve stimulation elicited rapid increases in glandular blood flow and induced salivary secretion from the three glands in both diabetic and nondiabetic rats. However, the magnitude of blood flow increase and salivary secretion in the parotid gland was significantly lower in the diabetic rats compared with the nondiabetic rats, although this was not observed in the other gland...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - March 25, 2020 Category: Physiology Authors: Sato T, Mito K, Ishii H Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Rats are Protected from the Stress of Chronic Pressure Overload as Compared with Mice.
Abstract The goal of this investigation was to compare the effects of chronic (4 weeks) transverse aortic constriction (TAC) in Sprague Dawley rats and C57BL/6J mice. TAC, after 1 day, induced similar left ventricular (LV) pressure gradients in both rats (n=7) and mice (n=7) (113 ± 5.4 vs. 103 ± 11.5 mmHg) and after 4 weeks, the % increase in LV hypertrophy, as reflected by LV/tibial length (51% vs 49%) were similar in rats (n=12) and mice (n=12). After 4 weeks of TAC LV systolic and diastolic function were preserved in TAC rats. In contrast, in TAC mice LV ejection fraction decreased by 31% compared...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - March 25, 2020 Category: Physiology Authors: Nishimura K, Oydanich M, Zhang J, Babici D, Fraidenraich D, Vatner DE, Vatner SF Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Challenges in the interpretation and therapeutic manipulation of human ingestive microstructure.
Abstract This Mini-Review focuses on the interpretative value of ingestive microstructure by summarizing observations from both rodent and human studies. Preliminary data on the therapeutic manipulation of distinct microstructural components of eating are also outlined. In rodents, the interpretative framework of ingestive microstructure mainly concentrates on deprivation state, palatability, satiation and on the role of learning from previous experiences. In humans, however, the control of eating is further influenced by genetic, psychosocial, cultural, and environmental factors which add complexity and challenge...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - March 19, 2020 Category: Physiology Authors: Gero D Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research

Cisplatin Nephrotoxicity Is Induced via Poly(ADP-ribose) Polymerase Activation in Adult Zebrafish and Mice.
In conclusion, these data suggest that adult zebrafish is not only suitable for drug screening and genetic manipulation, but also useful as a simplified but powerful model to study the pathophysiology of cisplatin nephrotoxicity and establish new therapies for treating human kidney diseases. PMID: 32186196 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology)
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - March 18, 2020 Category: Physiology Authors: Kim MJ, Moon D, Jung S, Lee J, Kim J Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research