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Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology

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https://www.readbyqxmd.com/read/29313093/baseline-glucose-level-is-an-individual-trait-that-is-negatively-associated-with-lifespan-and-increases-due-to-adverse-environmental-conditions-during-development-and-adulthood
#1
Bibiana Montoya, Michael Briga, Blanca Jimeno, Sander Moonen, Simon Verhulst
High baseline glucose levels are associated with pathologies and shorter lifespan in humans, but little is known about causes and consequences of individual variation in glucose levels in other species. We tested to what extent baseline blood glucose level is a repeatable trait in adult zebra finches, and whether glucose levels were associated with age, manipulated environmental conditions during development (rearing brood size) and adulthood (foraging cost), and lifespan. We found that: (1) repeatability of glucose levels was 30%, both within and between years...
January 9, 2018: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29299670/flexibility-is-the-key-metabolic-and-thermoregulatory-behaviour-in-a-small-endotherm
#2
Franz Langer, Nadine Havenstein, Joanna Fietz
Hibernation is the most effective way to reduce thermoregulatory costs during periods of unfavourable environmental conditions. In preparation to hibernation, fat-storing hibernators accumulate large quantities of body fat, which increases their locomotor costs and also the risk of predation. As a consequence, there should be a strong selective pressure to restrict pre-hibernation fattening to a short-time period before the onset of hibernation. The edible dormouse (Glis glis) is characterized by having adapted its whole life history to the irregularly occurring mast-seeding pattern of the European beech (Fagus sylvaticus)...
January 3, 2018: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29299669/air-breathing-behavior-oxygen-concentrations-and-ros-defense-in-the-swimbladders-of-two-erythrinid-fish-the-facultative-air-breathing-jeju-and-the-non-air-breathing-traira-during-normoxia-hypoxia-and-hyperoxia
#3
Bernd Pelster, Chris M Wood, Ellen Jung, Adalberto L Val
The jeju Hoplerythrinus unitaeniatus and the traira Hoplias malabaricus are two neighboring genera from the family of erythrinid fish, both possessing a two-chambered physostomous swimbladder. In the jeju the anterior section of the posterior bladder is highly vascularized, and the swimbladder is used for aerial respiration; the traira, in turn, is a water-breather that uses the swimbladder as a buoyancy organ and not for aerial oxygen uptake. Measurement of swimbladder oxygen partial pressure (PO2) of fish kept at 26 °C in normoxic, hyperoxic (28-32 mg O2 L- 1) or hypoxic (1-1...
January 3, 2018: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29290001/dropping-the-base-recovery-from-extreme-hypercarbia-in-the-co2-tolerant-pacific-hagfish-eptatretus-stoutii
#4
Alexander M Clifford, Alyssa M Weinrauch, Greg G Goss
Hagfish are capable of tolerating extreme hypercapnia (> 30 Torr) by mounting substantial plasma [HCO3-] (hypercarbia) to compensate for CO2-mediated acidosis. The goal of this study was to characterize the mechanistic hypercarbia-recovery strategies in the highly CO2 tolerant hagfish. We exposed hagfish to hypercapnia (30 Torr) for 48 h and allowed a 24 h recovery period in normocapnic seawater. Within 8 h of the recovery period, the compensatory plasma [HCO3-] load (~ 70 mmol L-1) was rapidly offloaded...
December 30, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29218398/enhanced-hemoglobin-oxygen-unloading-in-migratory-salmonids
#5
Jacelyn J Shu, Till S Harter, Phillip R Morrison, Colin J Brauner
Recent findings indicate that some teleost fishes may be able to greatly enhance hemoglobin-oxygen (Hb-O2) unloading at the tissues under conditions that result in catecholamine release. The putative mechanism relies on the high pH sensitivity of teleost hemoglobin (Hb), intracellular red blood cell (RBC) pH regulation via β-adrenergic Na+/H+ exchanger (β-NHE) activity, and plasma-accessible carbonic anhydrase at the tissues that short-circuits RBC pH regulation. Previous studies have shown that in rainbow trout, this system may double Hb-O2 unloading to red muscle compared to a situation without short-circuiting...
December 7, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29214347/partial-phenotype-conversion-and-differential-trait-response-to-conditions-of-husbandry-in-mice
#6
Julia Brenmoehl, Christina Walz, Marion Spitschak, Elisa Wirthgen, Michael Walz, Martina Langhammer, Armin Tuchscherer, Ronald Naumann, Andreas Hoeflich
Functional genome analysis usually is performed on the level of genotype-phenotype interaction. However, phenotypes also depend on the relations between genomes and environment. In our experimental system, we observed differential response to environmental factors defined by different conditions of husbandry in a semi-barrier unit or in a SPF (specific pathogen free) barrier unit, which resulted in partial reversal of phenotypes previously observed under semi-barrier conditions. To provide an update of basic phenotypes in unselected and randomly mated controls (DUC) and long-term selected DUhTP (Dummerstorf high treadmill performance) mice in the SPF facility, we compared growth parameters, reproductive performance, the accretion of muscle and fat mass, physical activity, and running performance as well as food intake in all experimental groups...
December 6, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29189935/the-physiology-of-the-tambaqui-colossoma-macropomum-at-ph-8-0
#7
Chris M Wood, R J Gonzalez, Márcio Soares Ferreira, Susana Braz-Mota, Adalberto Luis Val
The Tambaqui is a model neotropical teleost which is of great economic and cultural importance in artisanal fisheries and commercial aquaculture. It thrives in ion-poor, often acidic Amazonian waters and exhibits excellent regulation of physiology down to water pH 4.0. Curiously, however, it is reported to perform poorly in aquaculture at pH 8.0, an only slightly alkaline pH which would be benign for most freshwater fish. In initial experiments with Tambaqui of intermediate size (30-50 g), we found that ammonia excretion rate was unchanged at pH 4, 5, 6, and 7, but elevated after 20-24 h at pH 8, exactly opposite the pattern seen in most teleosts...
November 30, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29150716/slow-life-histories-in-lizards-living-in-the-highlands-of-the-andes-mountains
#8
Jorgelina M Boretto, Facundo Cabezas-Cartes, Nora R Ibargüengoytía
In the highlands of the Andes, lizards must balance precisely the allocation of energy for growth and reproduction to ensure their survival. We studied the individuals' age, growth rates, age at sexual maturity, and maximum life span of the viviparous lizard Phymaturus antofagastensis, endemic of cold and harsh environments at high altitudes in the Andes Mountains of Catamarca province, Argentina. We also estimated key life history parameters like reproductive effort, lifetime reproductive effort, net reproductive rate, and relative reproductive time in P...
November 17, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29130117/correction-to-the-metabolic-cost-of-nesting-body-condition-and-blood-parameters-of-caiman-crocodilus-and-melanosuchus-niger-in-central-amazonia
#9
José António Lemos Barão-Nóbrega, Boris Marioni, Robinson Botero-Arias, António José Arsénia Nogueira, Emerson Silva Lima, William Ernest Magnusson, Ronis Da Silveira, Jaydione Luiz Marcon
Although nesting ecology is well studied in several crocodilian species, it is not known how nest attendance influences physiology and body condition of nesting females. In this study, we describe body condition and serum biochemical values of nesting female, non-nesting female and male spectacled caiman (Caiman crocodilus) and black caiman (Melanosuchus niger) in two areas of Central Amazonia. We also evaluated the effect of nest age and nest distance to water on body condition and blood parameters of nesting females...
November 13, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29124322/air-breathing-changes-the-pattern-for-temperature-induced-ph-regulation-in-a-bimodal-breathing-teleost
#10
Christian Damsgaard, Mikkel Thy Thomsen, Mark Bayley, Tobias Wang
It is well established that ectothermic vertebrates regulate a lower arterial pH when temperature increases. Typically, water-breathers reduce arterial pH by altering plasma [HCO3(-)], whilst air-breathers rely on ventilatory adjustments to modulate arterial PCO2. However, no studies have investigated whether the shift from water- to air-breathing within a species changes the mechanisms for temperature-induced pH regulation. Here, we used the striped catfish Pangasianodon hypophthalmus to examine how pH regulation is affected by water- versus air-breathing, since P...
November 9, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29119278/development-of-endothermy-in-birds-patterns-and-mechanisms
#11
REVIEW
Edwin R Price, Edward M Dzialowski
Endothermy is a conspicuous and important adaptation in birds. Even though juvenile and adult birds are endothermic and maintain a constant, high body temperature by means of internal heat production, they begin life expressing an ectothermic phenotype. Depending on where a species falls along a continuum of maturity at hatching, from precocial to altricial, they begin to express endothermic traits either close to the time of hatching or as nestlings over a period of 1-3 weeks. Developing endothermy requires attaining a high basal metabolic rate and associated aerobic scope to produce sufficient internal heat, insulation to retain the internally produced heat, and a thermostat that "turns on" heat production in response to cooling ambient temperatures...
November 8, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29075844/changes-in-thermoregulation-and-monoamine-release-in-freely-moving-rats-during-cold-exposure-and-inhibition-of-the-ventromedial-dorsomedial-or-posterior-hypothalamus
#12
Takayuki Ishiwata, Benjamin N Greenwood
The hypothalamus is critical for regulating thermogenesis, but the role of monoamines in specific hypothalamic subregions in thermogenesis is not thoroughly established. The purpose of this study was to confirm changes of body temperature (T b) and thermoregulatory parameters upon inhibition of neural activity in hypothalamic subregions in freely moving rats. In addition, the pattern of monoamine release in these nuclei was measured during active thermoregulation using microdialysis. Tetrodotoxin (TTX) was perfused into the ventromedial hypothalamus (VMH), dorsomedial hypothalamus (DMH), or posterior hypothalamus (PH) at two different ambient temperatures (5 or 23 °C)...
October 26, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29071420/venous-pressures-and-cardiac-filling-in-turtles-during-apnoea-and-intermittent-ventilation
#13
William Joyce, Catherine J A Williams, Dane A Crossley, Tobias Wang
The amount of blood pumped by the heart (cardiac output) must be matched to the amount of blood returning to the heart (venous return), but the factors determining cardiac filling are sparsely understood in ectothermic vertebrates. Stroke volume is affected by heart rate along with central and peripheral venous pressures. In the present study, we investigated the heart rate dependency of cardiac filling in turtles, along with the changes in venous pressures that accompany ventilation. Experimental reductions in heart rate of anaesthetised turtles (Trachemys scripta) by the specific bradycardic agent zatebradine (2-3 mg kg(-1)) resulted in an elevation of stroke volume that compensated cardiac output...
October 25, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/29067494/effects-of-water-ionic-composition-on-acid-base-regulation-in-rainbow-trout-during-hypercarbia-at-rest-and-during-sustained-exercise
#14
Katelyn J Tovey, Colin J Brauner
Aquatic hypercarbia (elevated environmental CO2) results in a blood acidosis in fish, which is compensated by the exchange of Na(+) and/or Cl(-) for its acid/base counterpart (H(+), HCO3(-)) across the gill epithelium. To date, no studies exist on how a single species, capable of inhabiting both fresh and saltwater, responds to hypercarbia, at rest or during sustained exercise. Rainbow trout was acclimated to soft water (in mmol l(- 1): Na(+), 0.08; Cl(-), 0.05; pH 6.7-6.8), hard water (in mmol l(- 1): Na(+), 2...
October 24, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28447151/rhythms-in-the-endocrine-system-of-fish-a-review
#15
REVIEW
Mairi Cowan, Clara Azpeleta, Jose Fernando López-Olmeda
The environment which living organisms inhabit is not constant and many factors, such as light, temperature, and food availability, display cyclic and predictable variations. To adapt to these cyclic changes, animals present biological rhythms in many of their physiological variables, timing their functions to occur when the possibility of success is greatest. Among these variables, many endocrine factors have been described as displaying rhythms in vertebrates. The aim of the present review is to provide a thorough review of the existing knowledge on the rhythms of the endocrine system of fish by examining the hormones that show rhythmicity, how environmental factors control these rhythms and the variation in the responses of the endocrine system depending on the time of the day...
December 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28444441/the-activity-of-the-rectal-gland-of-the-north-pacific-spiny-dogfish-squalus-suckleyi-is-glucose-dependent-and-stimulated-by-glucagon-like-peptide-1
#16
Courtney A Deck, W Gary Anderson, J Michael Conlon, Patrick J Walsh
Elasmobranchs possess a specialised organ, the rectal gland, which is responsible for excreting sodium chloride via the posterior intestine. Previous work has indicated that the gland may be activated by a number of hormones, some of which are likely related to the salt or volume loads associated with feeding. Furthermore, evidence exists for the gland being glucose dependent which is atypical for an elasmobranch tissue. In this study, the presence of sodium-glucose co-transporters (SGLTs) in the rectal gland and their regulation by feeding were investigated...
December 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28439669/effects-of-desiccation-and-starvation-on-thermal-tolerance-and-the-heat-shock-response-in-forest-ants
#17
Andrew D Nguyen, Kerri DeNovellis, Skyler Resendez, Jeremy D Pustilnik, Nicholas J Gotelli, Joel D Parker, Sara Helms Cahan
Temperature increases associated with global climate change are likely to be accompanied by additional environmental stressors such as desiccation and food limitation, which may alter how temperature impacts organismal performance. To investigate how interactions between stressors influence thermal tolerance in the common forest ant, Aphaenogaster picea, we compared the thermal resistance of workers to heat shock with and without pre-exposure to desiccation or starvation stress. Knockdown (KD) time at 40.5 °C of desiccated ants was reduced 6% compared to controls, although longer exposure to desiccation did not further reduce thermal tolerance...
December 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28421289/adult-male-northern%C3%A2-elephant-seals-maintain-high-rates-of-glucose-production-during-extended-breeding-fasts
#18
Daniel E Crocker, Brian K Wenzel, Cory D Champagne, Dorian S Houser
Many species undergo natural fasts as part of their life histories. Extended fasting is associated with increased β-oxidation of fatty acids and reduced oxidation of glucose to minimize commitment of body protein to gluconeogenesis. However, the metabolic strategies used to sustain extended fasts simultaneous with high rates of energy expenditure are not well understood. Studies in fasting adult female and weanling northern elephant seals (NES) have revealed high rates of endogenous glucose production (EGP) under constraints of high nutrient demand for lactation or development but relatively low rates of metabolism...
December 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28409226/daily-thermal-fluctuations-to-a-range-of-subzero-temperatures-enhance-cold-hardiness-of-winter-acclimated-turtles
#19
James M Wiebler, Manisha Kumar, Timothy J Muir
Although seasonal increases in cold hardiness are well documented for temperate and polar ectotherms, relatively little is known about supplemental increases in cold hardiness during winter. Because many animals are exposed to considerable thermal variation in winter, they may benefit from a quick enhancement of cold tolerance prior to extreme low temperature. Hatchling painted turtles (Chrysemys picta) overwintering in their natal nests experience substantial thermal variation in winter, and recently, it was found that brief subzero chilling of winter-acclimated hatchlings decreases subsequent chilling-induced mortality, increases blood concentrations of glucose and lactate, and protects the brain from cryoinjury...
December 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28405747/metabolic-responses-to-different-immune-challenges-and-varying-resource-availability-in-the-side-blotched-lizard-uta-stansburiana
#20
Geoffrey D Smith, Lorin A Neuman-Lee, Alison C Webb, Michael J Angilletta, Dale F DeNardo, Susannah S French
The energetic cost of immunity depends on many factors, including the type of challenge, the timing of the response, and the state of the animal. We measured changes in the standard metabolic rates of side-blotched lizards (Uta stansburiana Baird and Girard, 1852) in response to different immune challenges and nutritional states. In the first experiment, lizards were randomly assigned to one of four treatments: lipopolysaccharide (LPS) injection (to stimulate the response to a pathogen), cutaneous biopsy (as a proxy to a superficial wound), both injection and biopsy, or neither (control)...
December 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
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