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.

Platelets from 13-lined ground squirrels are resistant to cold storage lesions
AbstractDuring torpor in a 13-lined ground squirrel heart rate and blood flow decrease, increasing the risk of blood clot formation. In response, cells involved in clotting calledplatelets are sequestered in the liver, stored in the cold for months, and released back into circulation upon arousal. This is in contrast to non-hibernating mammals, including humans, in which chilled platelets undergo cold storage lesions and phagocytosis, leading to rapid clearance from circulation post-transfusion. Because of this, human platelets must be stored at room temperature, limiting their shelf life to 7  days due to the increased r...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - December 10, 2022 Category: Physiology Source Type: research

Insect phenoloxidase and its diverse roles: melanogenesis and beyond
AbstractInsect life on earth is greatly diversified despite being exposed to several infectious agents due to their diverse habitats and ecological niche. One of the major factors responsible for their successful establishment is having a powerful innate immune system. The most common and effective method used by insects in recognizing pathogen and non-self-substances is the melanization process among others. The key enzyme involved in melanin biosynthesis is the copper containing humoral defense enzyme, phenoloxidase (PO). This review focused on understanding about PO and that had been in research for nearly a century. Th...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - December 6, 2022 Category: Physiology Source Type: research

Differences in the regulatory mechanism of blood flow in the orofacial area mediated by neural and humoral systems
This study examined whether there are differences in changes in the BF and vascular conductance (VC) between the masseter muscle and lower lip mediated by autonomic neural and humoral systems in urethane-anesthetized rats. Electrical stimulation of the central cut end of the lingual nerve elicited BF increases in the masseter (mainly cholinergic) and lower lip (mainly non-cholinergic), accompanied by an increase in arterial blood pressure (ABP), while cervical sympathetic trunk stimulation consistently decreased BF at both sites. The lingual nerve stimulation induced a biphasic change in the VC in the masseter, consisting ...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - November 27, 2022 Category: Physiology Source Type: research

Social isolation does not alter the relationship between flexibility in metabolic rate and growth in grass carp (Ctenopharyngodon idella) under changing food availability
AbstractGrowth and energy metabolism are highly flexible in fish species in response to food availability, and these two traits depend to some extent on the social rearing environment (e.g., isolatedvs. group rearing). Currently, how social rearing environments influence flexibility in metabolic rate of fish and their ecological consequences (e.g., somatic growth) remain largely unknown. Here, we investigated how social isolation (i.e., group-rearedvs. isolation-reared) and food availability (i.e., highvs. low) affect metabolic rates, growth and their correlations in a group-living fish, grass carp (Ctenopharyngodon idella...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - November 10, 2022 Category: Physiology Source Type: research

Relating spidroin motif prevalence and periodicity to the mechanical properties of major ampullate spider silks
This study serves as a primer for investigating the molecular properties of spidroins that underlie species-specificα* values. Initial findings are that while overall motif composition was similar between species, certain motifs and higher level periodicities of glycine-rich region lengths showed variation, notably greater distances between poly-A motifs inA. aurantia sequences. In addition to increased period lengths,A. aurantia spidroins tended to have an increased prevalence of charged and hydrophobic residues. These increases may impact the number and strength of hydrogen bond networks within fibers, which have been i...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - November 7, 2022 Category: Physiology Source Type: research

Energy expenditure and body composition in a hibernator, the alpine marmot
AbstractVisceral organs and tissues of 89 free-living alpine marmots (Marmota marmota) shot during a population control program in Switzerland, were collected. Between emergence from hibernation in April to July, the gastrointestinal tract (stomach to colon) gained 51% of mass and the liver mass increased by 24%. At the same time, the basal metabolic rate (BMR), determined with a portable oxygen analyzer, increased by 18%. The organ masses of the digestive system (stomach, small intestine, caecum, large intestine) were all significantly correlated with BMR. Interestingly, the mass of abdominal white adipose tissue (WAT) an...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - November 6, 2022 Category: Physiology Source Type: research

Skin ionocyte density of amphibious killifishes is shaped by phenotypic plasticity and constitutive interspecific differences
AbstractWhen amphibious fishes are on land, gill function is reduced or eliminated and the skin is hypothesized to act as a surrogate site of ionoregulation. Skin ionocytes are present in many fishes, particularly those with amphibious life histories. We used nine closely related killifishes spanning a range of amphibiousness to first test the hypothesis that amphibious killifishes have evolved constitutively increased skin ionocyte density to promote ionoregulation on land. We found that skin ionocyte densities were constitutively higher in five of seven amphibious species examined relative to exclusively water-breathing ...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - November 1, 2022 Category: Physiology Source Type: research

A comparative and ontogenetic examination of mitochondrial function in Antarctic notothenioid species
In this study we examined aerobic metabolic capacity in three species,Trematomus bernacchii,T. pennellii andT. newnesi, and between two life stages, juvenile and adult, by assessing mitochondrial function of permeabilized cardiac fibers. Respiratory capacity differed among the adult notothenioids in this study, with greater oxidative phosphorylation (OXPHOS) respiration in the pelagicT. newnesi than the benthicT. bernacchii andT. pennellii. The variation in mitochondrial respiratory capacity was likely driven by differences in the mitochondrial content, as measured by citrate synthase activity, which was the highest inT. n...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - November 1, 2022 Category: Physiology Source Type: research

Mitochondrial oxidative phosphorylation response overrides glucocorticoid-induced stress in a reptile
In conclusion, global mitochondrial functioning has to be considered to better understand the proximal causes of the energy budget under stressful periods. (Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology)
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - November 1, 2022 Category: Physiology Source Type: research