journal
MENU ▼
Read by QxMD icon Read
search

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

journal
https://www.readbyqxmd.com/read/28432393/more-functions-of-torpor-and-their-roles-in-a-changing-world
#1
Julia Nowack, Clare Stawski, Fritz Geiser
Increased winter survival by reducing energy expenditure in adult animals is often viewed as the primary function of torpor. However, torpor has many other functions that ultimately increase the survival of heterothermic mammals and birds. In this review, we summarize new findings revealing that animals use torpor to cope with the conditions during and after natural disasters, including fires, storms, and heat waves. Furthermore, we suggest that torpor, which also prolongs longevity and was likely crucial for survival of mammals during the time of the dinosaur extinctions, will be advantageous in a changing world...
April 21, 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
#2
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...
April 18, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28417150/torpor-patterns-in-common-hamsters-with-and-without-access-to-food-stores
#3
Carina Siutz, Eva Millesi
Hibernating species significantly reduce energy expenditure during winter by entering torpor. Nevertheless, the various benefits of hibernation might be counteracted by negative effects of torpor such as immune depression, oxidative stress, or neuronal impairment. Considering these trade-offs, adequate energy reserves could allow animals to reduce the time spent in torpor or the extent of metabolic depression. Common hamsters use food stores during hibernation and previously documented high individual variations in body temperature patterns during winter could, therefore, be related to differences in external energy reserves...
April 17, 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
#4
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...
April 13, 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
#5
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)...
April 12, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28401294/drinking-and-water-permeability-in-the-pacific-hagfish-eptatretus-stoutii
#6
Chris N Glover, Chris M Wood, Greg G Goss
Hagfish are osmoconformers, maintaining an internal osmolality that matches their seawater habitats. Hagfish would, therefore, appear to have no physiological need to drink, but previous studies are equivocal regarding whether drinking in hagfish occurs. The current study addressed this knowledge gap, by examining drinking and water permeability in the Pacific hagfish, Eptatretus stoutii. One-third of analysed hagfish were shown to accumulate radiolabelled drinking rate markers (tritiated inulin and polyethylene glycol-4000) in their gut tissues; however, this was attributed to the presence of markers in the blood perfusing the digestive tract, following absorption through paracellular pathways at the gill...
April 11, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28401293/how-low-can-you-go-an-adaptive-energetic-framework-for-interpreting-basal-metabolic-rate-variation-in-endotherms
#7
REVIEW
David L Swanson, Andrew E McKechnie, François Vézina
Adaptive explanations for both high and low body mass-independent basal metabolic rate (BMR) in endotherms are pervasive in evolutionary physiology, but arguments implying a direct adaptive benefit of high BMR are troublesome from an energetic standpoint. Here, we argue that conclusions about the adaptive benefit of BMR need to be interpreted, first and foremost, in terms of energetics, with particular attention to physiological traits on which natural selection is directly acting. We further argue from an energetic perspective that selection should always act to reduce BMR (i...
April 11, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28397031/living-in-a-seasonal-world-15th-international-hibernation-symposium
#8
EDITORIAL
Frank van Breukelen, Jenifer Utz
No abstract text is available yet for this article.
April 10, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28391591/syrian-hamster-neuroplasticity-mechanisms-fail-as-temperature-declines-to-15%C3%A2-%C3%A2-c-but-histaminergic-neuromodulation-persists
#9
Jock S Hamilton, Sat M Chau, Kevin J Malins, Giancarlo G Ibanez, John M Horowitz, Barbara A Horwitz
Previous research suggests that hippocampal neurons in mammalian hibernators shift their major function from memory formation at euthermic brain temperatures (T b = ~37 °C) to modulation of hibernation bout duration as T b decreases. This role of hippocampal neurons during torpor is based in part on in vivo studies showing that histamine (HA) infused into ground squirrel hippocampi lengthened torpor bouts by ~50%. However, it was unclear if HA acted directly on hippocampal neurons or on downstream brain regions via HA spillover into lateral ventricles...
April 9, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28391590/effects-of-heat-stress-on-the-renal-and-branchial-carbohydrate-metabolism-and-antioxidant-system-of-antarctic-fish
#10
Mariana Forgati, Priscila Krebsbach Kandalski, Tatiana Herrerias, Tania Zaleski, Cintia Machado, Maria Rosa Dmengeon Pedreiro Souza, Lucélia Donatti
The objective of the present study was to assess the effect of short-term (2-144 h) heat stress (8 °C) on energy production processes and antioxidant defense systems in the kidneys and gills of Notothenia rossii and Notothenia coriiceps. Heat stress affected energy metabolism and oxidative stress parameters in a time-, tissue-, and species-dependent manner, and gills were more sensitive than kidneys to heat stress. N. rossii kidneys were able to stabilize carbohydrate metabolism after 12 h of heat stress, whereas the glycogen levels in N...
April 8, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28389697/antioxidant-capacity-lipid-peroxidation-and-lipid-composition-changes-during-long-term-and-short-term-thermal-acclimation-in-daphnia
#11
Bret L Coggins, John W Collins, Kailea J Holbrook, Lev Y Yampolsky
Examples of phenotypic plasticity-the ability of organisms of identical genotypes to produce different phenotypes in response to the environment-are abundant, but often lack data on the causative physiology and biochemistry. Phenotypes associated with increased protection against or reduced damage from harmful environments may, in fact, be downstream effects of hidden adaptive responses that remain elusive to experimental measurement or be obscured by homeostatic or over-compensatory effects. The freshwater zooplankton crustacean Daphnia drastically increases its heat tolerance as the result of acclimation to high temperatures, an effect often assumed to be based on plastic responses allowing better protection against oxidative stress...
April 7, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28389696/temperature-increases-hypoxia-and-changes-in-food-availability-affect-immunological-biomarkers-in-the-marine-mussel-mytilus-galloprovincialis
#12
M G Parisi, M Mauro, G Sarà, M Cammarata
Temperature increases, hypoxia, and changes in food availability are predicted to occur in the future. There is growing concern for the health status of wild and farmed organisms, since environmental stressors alter organism functions, and elicit coordinated physiological responses for homeostasis. Mussels are good bioindicators of environmental conditions. Their ability to maintain unaltered immunosurveillance under adverse environmental conditions may enhance their survival capability. Few studies are currently concerned with the relationships and feedback among multiple stressors...
April 7, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28389695/effects-of-low-temperature-on-breathing-pattern-and-ventilatory-responses-during-hibernation-in-the-golden-mantled-ground-squirrel
#13
Cheryl L Webb, William K Milsom
During entrance into hibernation in golden-mantled ground squirrels (Callospermophilus lateralis), ventilation decreases as metabolic rate and body temperature fall. Two patterns of respiration occur during deep hibernation. At 7 °C body temperature (T b ), a breathing pattern characterized by episodes of multiple breaths (20.6 ± 1.9 breaths/episode) separated by long apneas or nonventilatory periods (T nvp ) (mean = 11.1 ± 1.2 min) occurs, while at 4 °C T b , a pattern in which breaths are evenly distributed and separated by a relatively short T nvp (0...
April 7, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28382530/the-interactive-effect-of-digesting-a-meal-and-thermal-acclimation-on-maximal-enzyme-activities-in-the-gill-kidney-and-intestine-of-goldfish-carassius-auratus
#14
Leah A Turner, Carol Bucking
Surrounding environmental temperatures affect many aspects of ectotherm physiology. Generally, organisms can compensate at one or more biological levels, or allow temperature to dictate processes such as enzyme activities through kinetic effects on reaction rates. As digestion also alters physiological processes such as enzyme activities, this study determined the interacting effect of thermal acclimation (8 and 20 °C) and digesting a single meal on maximal enzyme activities in three tissues of the goldfish (Carrassius auratus)...
April 5, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28378088/central-activation-of-the-a1-adenosine-receptor-in-fed-mice-recapitulates-only-some-of-the-attributes-of-daily-torpor
#15
Maria A Vicent, Ethan D Borre, Steven J Swoap
Mice enter bouts of daily torpor, drastically reducing metabolic rate, core body temperature (T b), and heart rate (HR), in response to reduced caloric intake. Because central adenosine activation has been shown to induce a torpor-like state in the arctic ground squirrel, and blocking the adenosine-1 (A1) receptor prevents daily torpor, we hypothesized that central activation of the A1 adenosine receptors would induce a bout of natural torpor in mice. To test the hypothesis, mice were subjected to four different hypothermia bouts: natural torpor, forced hypothermia (FH), isoflurane-anesthesia, and an intracerebroventricular injection of the selective A1 receptor agonist N(6-)cyclohexyladenosine (CHA)...
April 4, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28365894/gene-expression-analysis-and-microdialysis-suggest-hypothalamic-triiodothyronine-t3-gates-daily-torpor-in-djungarian-hamsters-phodopus-sungorus
#16
Jonathan H H Bank, Ceyda Cubuk, Dana Wilson, Eddy Rijntjes, Julia Kemmling, Hanna Markovsky, Perry Barrett, Annika Herwig
Thyroid hormones play an important role in regulating seasonal adaptations of mammals. Several studies suggested that reduced availability of 3,3',5-triiodothyronine (T3) in the hypothalamus is required for the physiological adaptation to winter in Djungarian hamsters. We have previously shown that T3 is involved in the regulation of daily torpor, but it remains unclear, whether T3 affects torpor by central or peripheral mechanisms. To determine the effect of T3 concentrations within the hypothalamus in regulating daily torpor, we tested the hypothesis that low hypothalamic T3 metabolism would favour torpor and high T3 concentrations would not...
April 1, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28364393/lipid-emulsion-enhances-cardiac-performance-after-ischemia-reperfusion-in-isolated-hearts-from-summer-active-arctic-ground-squirrels
#17
Michele M Salzman, Qunli Cheng, Richard J Deklotz, Gurpreet K Dulai, Hunter F Douglas, Anna E Dikalova, Dorothee Weihrauch, Brian M Barnes, Matthias L Riess
Hibernating mammals, like the arctic ground squirrel (AGS), exhibit robust resistance to myocardial ischemia/reperfusion (IR) injury. Regulated preference for lipid over glucose to fuel metabolism may play an important role. We tested whether providing lipid in an emulsion protects hearts from summer-active AGS better than hearts from Brown Norway (BN) rats against normothermic IR injury. Langendorff-prepared AGS and BN rat hearts were perfused with Krebs solution containing 7.5 mM glucose with or without 1% Intralipid™...
March 31, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28353178/identification-of-hif-1-signaling-pathway-in-pelteobagrus-vachelli-using-rna-seq-effects-of-acute-hypoxia-and-reoxygenation-on-oxygen-sensors-respiratory-metabolism-and-hematology-indices
#18
Guosong Zhang, Cheng Zhao, Qintao Wang, Yichun Gu, Zecheng Li, Panfeng Tao, Jiawei Chen, Shaowu Yin
Oxygen is a vital element in aquatic environments. The concentration of oxygen to which aquatic organisms are exposed is influenced by salinity, water temperature, weather, and surface water runoff. Hypoxia has a serious effect on fish populations, and can lead to the loss of habitat and die-offs. Therefore, in the present study we used next-generation sequencing technology to characterize the transcriptomes of Pelteobagrus vachelli and identified 70 candidate genes in the HIF-1 signaling pathway that are important for the hypoxic response in all metazoan species...
March 28, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28353177/embracing-heterothermic-diversity-non-stationary-waveform-analysis-of-temperature-variation-in-endotherms
#19
Danielle L Levesque, Allyson K Menzies, Manuelle Landry-Cuerrier, Guillaume Larocque, Murray M Humphries
Recent research is revealing incredible diversity in the thermoregulatory patterns of wild and captive endotherms. As a result of these findings, classic thermoregulatory categories of 'homeothermy', 'daily heterothermy', and 'hibernation' are becoming harder to delineate, impeding our understanding of the physiological and evolutionary significance of variation within and around these categories. However, we lack a generalized analytical approach for evaluating and comparing the complex and diversified nature of the full breadth of heterothermy expressed by individuals, populations, and species...
March 28, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28349198/benign-neonatal-deep-hypothermia-in-rodents-and-its-relations-to-hibernation
#20
Richard W Hill
The neonates of many rodent species survive deep hypothermia (T b = 0-8 °C). In key respects, this hypothermia is more akin to hibernation than was thought during much of the twentieth century, indicating that studies of neonatal hypothermia may usefully supplement studies of hibernation in understanding evolved tissue adaptations to near-freezing T b. To clarify evolutionary diversity in neonatal survival of deep hypothermia, neonates of six species or strains were subjected to a standardized procedure: exposure for 2...
March 27, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
journal
journal
28919
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"