Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Genetic repression of the antioxidant enzymes reduces the lifespan in Drosophila melanogaster
AbstractAging is a biological process associated with gradual loss of function caused by cellular and molecular damages ultimately leading to mortality. Free radicals are implicated in oxidative damage which affects the longevity of organisms. Natural cellular defenses involving antioxidant enzymes delay or prevent oxidative damage and, therefore, influence the aging process and longevity has been shown in many species includingDrosophila. We and others have shown that oxidative resistance is an important mechanism in the aging process inDrosophila. Therefore, we hypothesized that repressing endogenous antioxidant defenses...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - October 8, 2021 Category: Physiology Source Type: research

Continuous gastric saline perfusion elicits cardiovascular responses in freshwater rainbow trout (Oncorhynchus mykiss)
AbstractWhen in seawater, rainbow trout (Oncorhynchus mykiss) drink to avoid dehydration and display stroke volume (SV) mediated elevations in cardiac output (CO) and an increased proportion of CO is diverted to the gastrointestinal tract as compared to when in freshwater. These cardiovascular alterations are associated with distinct reductions in systemic and gastrointestinal vascular resistance (RSys andRGI, respectively). Although increased gastrointestinal blood flow (GBF) is likely essential for osmoregulation in seawater, the sensory functions and mechanisms driving the vascular resistance changes and other associate...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - October 7, 2021 Category: Physiology Source Type: research

Cold and warm waters: energy metabolism and antioxidant defenses of the freshwater fish Astyanax lacustris (Characiformes: Characidae) under thermal stress
In this study, we addressed the effects of temperature variation on the metabolism ofAstyanax lacustris, a species of freshwater fish common in the subtropical region of Brazil. Biomarkers of carbohydrate and protein metabolism, antioxidant defense, and oxidative damage were evaluated in the liver ofA. lacustris exposed to low (15  °C) and high (31 °C) temperature thermal shock, with controls at 23 °C for 2, 6, 12, 24, 48, 72, and 96 h. A high energy demand was observed during the first 48 h of exposure to 15 °C, which is necessary for metabolic adjustment at low temperatures, with an increase in glycolysis, citr...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 30, 2021 Category: Physiology Source Type: research

Significance of variation in basal metabolic rate in laboratory mice for translational experiments
AbstractThe basal metabolic rate (BMR) accounts for 60 –70% of the daily energy expenditure (DEE) in sedentary humans and at least 50% of the DEE in laboratory mice in the thermoneutral zone. Surprisingly, however, the significance of the variation in the BMR is largely overlooked in translational research using such indices as physical activity level (PAL), i.e., the ratio of DEE/BMR. In particular, it is unclear whether emulation of human PAL in mouse models should be carried out within or below the thermoneutral zone. It is also unclear whether physical activity within the thermoneutral zone is limited by the capacity...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 30, 2021 Category: Physiology Source Type: research

Mitogen-activated protein kinases contribute to temperature-induced cardiac remodelling in rainbow trout (Oncorhynchus mykiss)
AbstractRainbow trout (Oncorhynchus mykiss) live in environments where water temperatures range between 4  °C and 20 °C. Laboratory studies demonstrate that cold and warm acclimations of male trout can have oppositional effects on cardiac hypertrophy and the collagen content of the heart. The cellular mechanisms behind temperature-induced cardiac remodelling are unclear, as is why this response diff ers between male and female fish. Studies with cultured trout cardiac fibroblasts suggests that collagen deposition is regulated, at least in part, by mitogen-activated protein kinase (MAPK) cell signalling pathways. We, th...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 29, 2021 Category: Physiology Source Type: research

Intracellular taurine deficiency impairs cardiac contractility in rainbow trout (Oncorhynchus mykiss) without affecting aerobic performance
AbstractTaurine is a non-proteinogenic sulfonic acid found in high concentrations inside vertebrate cardiomyocytes and its movement across the sarcolemmal membrane is critical for cell volume regulation. Taurine deficiency is rare in mammals, where it impairs cardiac contractility and leads to congestive heart failure. In fish, cardiac taurine levels vary substantially between species and can decrease by up to 60% in response to environmental change but its contribution to cardiac function is understudied. We addressed this gap in knowledge by generating a taurine-deficient rainbow trout (Oncorhynchus mykiss) model using a...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 28, 2021 Category: Physiology Source Type: research

An expos é of Frappellian Motion
AbstractContrary to the well-recognised role of an abstract in helping to summarise the main points of the following article, this abstract takes its influence from Peter B. Frappell ( ‘Frapps’) and, therefore, is distracted from its key purpose. While the abstract was supposed to discuss the serious phenomenon of ‘Frappellian Motion’ (FM), someone just passed along some gossip that is heaps more exciting, so “let’s go grab a beer and I’ll talk at you”. (Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology)
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 14, 2021 Category: Physiology Source Type: research

Editorial: Untangling the oxygen transport cascade: a tribute to Peter Frappell (Frapps)
AbstractThis collection of research articles was put together in honour of respiratory physiologist Professor Peter Frappell ’s (Frapps’s) academic achievements. It encompasses various topics relating to the oxygen transport cascade, which was central to Frapps’ career as a comparative physiologist. This issue highlights the diversity and outreach of his influence on the field and his pioneering spirit; promoting no vel perspectives, methodologies and research techniques. This issue also demonstrates how Frapps’ knowledge and scientific findings answered some of the fundamental questions within the field of respira...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 31, 2021 Category: Physiology Source Type: research

The high-altitude bird chronicles: lessons from field work with Frapps
AbstractOver the past decade, Peter Frappell, aka Frapps, has been an integral part of an international group studying birds that migrate or reside at altitude. This research has taken the extended group from Terkhiin Tsagaan Lake on the Mongolian plateau to Chilika Lake in eastern India, Koonthankulum bird sanctuary in southern India, Lake Qinghai in Chinese Tibet, Summer Lake Wildlife and Malheur National Wildlife Refuge in Oregon, and San Pedro a Marca, Vichaycocha and Lake Titicaca National Reserve in Per ú. It has been a productive project producing over 30 manuscripts, 15 of which were based on research in the field...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 30, 2021 Category: Physiology Source Type: research

Melatonin is involved in the modulation of the hypothalamic and pituitary activity in the South American plains vizcacha, Lagostomus maximus
AbstractMelatonin, the key messenger of photoperiodic information, is synthesized in the pineal gland by arylalkylamineN-acetyltransferase enzyme (AANAT). It binds to specific receptors MT1 and MT2 located in the hypothalamus and pituitary gland. Melatonin can modulate the reproductive axis affecting the secretion of gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH). The South American plains vizcacha,Lagostomus maximus, shows natural poliovulation of up to 800  oocytes per estrous cycle, a 154-day long pregnancy, and reactivation of the reproductive axis at mid-gestation with pre-ovulatory follicular rec...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 30, 2021 Category: Physiology Source Type: research

The goldfish Carassius auratus: an emerging animal model for comparative cardiac research
AbstractThe use of unconventional model organisms is significantly increasing in different fields of research, widely contributing to advance life sciences understanding. Among fishes, the cyprinidCarassius auratus (goldfish) is largely used for studies on comparative and evolutionary endocrinology, neurobiology, adaptive and conservation physiology, as well as for translational research aimed to explore mechanisms that may be useful in an applicative biomedical context. More recently, the research possibilities offered by the goldfish are further expanded to cardiac studies. A growing literature is available to illustrate...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 28, 2021 Category: Physiology Source Type: research

Immune activation affects whole-organism performance in male but not female green anole lizards (Anolis carolinensis)
AbstractImmune responses are intuitively beneficial, but they can incur a variety of costs, many of which are poorly understood. The nature and extent of trade-offs between immune activity and other components of the integrated phenotype can vary, and depend on the type of immune challenge, as well as the energetic costs of simultaneously expressing other traits. There may also be sex differences in both immune activity and immunity-induced trade-offs, particularly in the case of trade-offs involving functional traits such as whole-organism performance capacities that might be of different fitness value to males and female...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 23, 2021 Category: Physiology Source Type: research

Similar hibernation physiology in bats across broad geographic ranges
AbstractSpecies with broad geographic ranges may experience varied environmental conditions throughout their range leading to local adaptation. Variation among populations reflects potential adaptability or plasticity, with implications for populations impacted by disease, climate change, and other anthropogenic influences. However, behavior may counteract divergent selection among populations. We studied intraspecific variation in hibernation physiology ofMyotis lucifugus (little brown myotis) andCorynorhinus townsendii (Townsend ’s big-eared bat), two species of bats with large geographic ranges. We studiedM. lucifugus...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 23, 2021 Category: Physiology Source Type: research

Sulfakinins influence lipid composition and insulin-like peptides level in oenocytes of Zophobas atratus beetles
AbstractInsect sulfakinins are pleiotropic neuropeptides with the homology to vertebrate gastrin/cholecystokinin peptide family. They have been identified in many insect species and affect different metabolic processes. They have a strong influence on feeding and digestion as well as on carbohydrate and lipid processing. Our study reveals that sulfakinins influence fatty acids composition inZophobas atratus oenocytes and regulate insulin-like peptides (ILPs) level in these cells. Oenocytes are cells responsible for maintenance of the body homeostasis and have an important role in the regulation of intermediary metabolism, ...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 20, 2021 Category: Physiology Source Type: research

Arginine vasotocin affects motivation to call, but not calling plasticity, in Cope ’s gray treefrog Hyla chrysoscelis
We examined the effects of the neuropeptide arginine vasotocin (AVT), which is implicated in social behavior in non-mammalian vertebrates, on both spontaneous acoustic advertisement calling behavior and the plastic response to a simulated competitive challenge in Cope ’s gray treefrogs,Hyla chrysoscelis. We injected males either with AVT or a saline control and then analyzed recordings of spontaneous calling prior to playback, playback of average advertisement calls, playback of highly competitive advertisement calls, and spontaneous calling after playback. We found a tendency for AVT-treated males to be more likely to r...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 16, 2021 Category: Physiology Source Type: research