scholarly journals Effects of temperature on plasma corticosterone in a native lizard

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Andrea Racic ◽  
Catherine Tylan ◽  
Tracy Langkilde
Keyword(s):  
Stress Response ◽  
Body Temperature ◽  
Restraint Stress ◽  
Field Measurements ◽  
Plasma Corticosterone ◽  
Lower Body ◽  
Body Temperatures ◽  
Sceloporus Undulatus ◽  
Laboratory Conditions ◽  
Effects Of Temperature

Abstract The glucocorticoid stress response is frequently used to indicate vertebrate response to the environment. Body temperature may affect glucocorticoid concentrations, particularly in ectotherms. We conducted lab manipulations and field measurements to test the effects of body temperature on plasma corticosterone (predominant glucocorticoid in reptiles) in eastern fence lizards (Sceloporus undulatus). First, we acclimated lizards to one of 4 treatments: 22 °C, 29 °C, 33 °C, or 36 °C, and measured cloacal temperatures and plasma corticosterone concentrations at baseline and after exposure to a standardized stressor (cloth bag). Both baseline and stress-induced corticosterone concentrations were lower in lizards with lower body temperatures. Second, we acclimated lizards to 22 °C or 29 °C and exposed them to a standardized (cloth bag) stressor for 3 to 41 min. Lizards acclimated to 29 °C showed a robust increase in plasma corticosterone concentrations with restraint stress, but those at 22 °C showed no such increases in corticosterone concentrations. Third, we measured lizards upon capture from the field. There was no correlation between body temperature and baseline plasma corticosterone in field-caught lizards. These results suggest body temperature can significantly affect plasma corticosterone concentrations in reptiles, which may be of particular concern for experiments conducted under laboratory conditions but may not translate to the field.

Adrenocorticotropic hormone and corticosterone responses to acute hypoxia in the neonatal rat: effects of body temperature maintenance

2011 ◽  
Vol 300 (3) ◽  
pp. R708-R715 ◽  
Author(s):  
Eric D. Bruder ◽  
Kimberli J. Kamer ◽  
Mitchell A. Guenther ◽  
Hershel Raff
Keyword(s):  
Stress Response ◽  
Body Temperature ◽  
Acute Hypoxia ◽  
Plasma Corticosterone ◽  
Neonatal Rat ◽  
Plasma Acth ◽  
Neonatal Hypoxia ◽  
Rat Pups ◽  
Expression Of Genes ◽  
Corticosterone Response

The corticosterone response to acute hypoxia in neonatal rats develops in the 1st wk of life, with a shift from ACTH independence to ACTH dependence. Acute hypoxia also leads to hypothermia, which may be protective. There is little information about the endocrine effects of body temperature maintenance during periods of neonatal hypoxia. We hypothesized that prevention of hypothermia during neonatal hypoxia would augment the adrenocortical stress response. Rat pups separated from their dams were studied at postnatal days 2 and 8 ( PD2 and PD8). In one group of pups, body temperature was allowed to spontaneously decrease during a 30-min prehypoxia period. Pups were then exposed to 8% O2 for 3 h and allowed to become spontaneously hypothermic or externally warmed (via servo-controlled heat) to maintain isothermia. In another group, external warming was used to maintain isothermia during the prehypoxia period, and then hypoxia with or without isothermia was applied. Plasma ACTH and corticosterone and mRNA expression of genes for upstream proteins involved in the steroidogenic pathway were measured. Maintenance of isothermia during the prehypoxia period increased baseline plasma ACTH at both ages. Hypothermic hypoxia caused an increase in plasma corticosterone; this response was augmented by isothermia at PD2, when the response was ACTH-independent, and at PD8, when the response was ACTH-dependent. In PD8 rats, isothermia also augmented the plasma ACTH response to hypoxia. We conclude that maintenance of isothermia augments the adrenocortical response to acute hypoxia in the neonate. Prevention of hypothermia may increase the stress response during neonatal hypoxia, becoming more pronounced with increased age.

A STUDY OF BLOOD PRESSURE RESPONSES DURING HYPOTHERMIA IN HYPOPHYSECTOMIZED RATS

1964 ◽  
Vol 42 (2) ◽  
pp. 209-215 ◽  
Author(s):  
J. Hunter ◽  
R. E. Haist
Keyword(s):  
Blood Pressure ◽  
Body Temperature ◽  
The Body ◽  
Lower Body ◽  
Body Temperatures ◽  
Renal Vessels ◽  
Hypophysectomized Rats ◽  
Blood Pressure Responses ◽  
Cooling Procedure ◽  
Intact Rats

When intact rats are cooled, the blood pressure is well maintained down to a body temperature of 22 °C, below which it rapidly falls. When hypophysectomized rats are cooled the reduction in blood pressure bears a linear relation to the body temperature. The infusion of Pitressin into hypophysectomized animals during the cooling procedure restores the blood pressure – body temperature relationship to that seen in intact rats. This occurs whether or not the renal vessels are ligated and hence appears to be independent of renal factors. However, when the kidneys are exteriorized and warmed and, at the same time, Pitressin is infused into the hypophysectomized cooled rats, there is an excellent maintenance of blood pressure at the lower body temperatures, the blood pressure being 110 mm Hg when the body temperature is 12 °C. Infusions of angiotensin II and of renin also are effective in maintaining blood pressure in hypothermic hypophysectomized animals. This effect of renin is not influenced by exteriorizing and warming the kidneys, hence the enhancement of the effect of Pitressin by this procedure is not a consequence of the warming alone. Warming the exteriorized kidneys may release some factor or cause some change which, in the presence of Pitressin, effectively maintains blood pressure at low body temperatures.

scholarly journals The Effects of Temperature on the Kinematics of Rattlesnake Predatory Strikes in Both Captive and Field Environments

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
M D Whitford ◽  
G A Freymiller ◽  
T E Higham ◽  
R W Clark
Keyword(s):  
Body Temperature ◽  
New World ◽  
Environmental Temperature ◽  
Maximum Velocity ◽  
Locomotor Performance ◽  
Body Temperatures ◽  
Predator Prey ◽  
Predatory Strike ◽  
Effects Of Temperature ◽  
The Difference

Abstract The outcomes of predator–prey interactions between endotherms and ectotherms can be heavily influenced by environmental temperature, owing to the difference in how body temperature affects locomotor performance. However, as elastic energy storage mechanisms can allow ectotherms to maintain high levels of performance at cooler body temperatures, detailed analyses of kinematics are necessary to fully understand how changes in temperature might alter endotherm–ectotherm predator–prey interactions. Viperid snakes are widely distributed ectothermic mesopredators that interact with endotherms both as predator and prey. Although there are numerous studies on the kinematics of viper strikes, surprisingly few have analyzed how this rapid movement is affected by temperature. Here we studied the effects of temperature on the predatory strike performance of rattlesnakes (Crotalus spp.), abundant new world vipers, using both field and captive experimental contexts. We found that the effects of temperature on predatory strike performance are limited, with warmer snakes achieving slightly higher maximum strike acceleration, but similar maximum velocity. Our results suggest that, unlike defensive strikes to predators, rattlesnakes may not attempt to maximize strike speed when attacking prey, and thus the outcomes of predatory strikes may not be heavily influenced by changes in temperature.

scholarly journals The effects of temperature on the defensive strikes of rattlesnakes

2020 ◽  
Vol 223 (14) ◽  
pp. jeb223859 ◽  
Author(s):  
Malachi D. Whitford ◽  
Grace A. Freymiller ◽  
Timothy E. Higham ◽  
Rulon W. Clark
Keyword(s):  
Body Temperature ◽  
Effect Of Temperature ◽  
Muscle Physiology ◽  
Marginal Effect ◽  
Body Temperatures ◽  
Predator Prey ◽  
Skeletal Muscle Contraction ◽  
Risk Of Predation ◽  
Crotalus Oreganus ◽  
Effects Of Temperature

ABSTRACTMovements of ectotherms are constrained by their body temperature owing to the effects of temperature on muscle physiology. As physical performance often affects the outcome of predator–prey interactions, environmental temperature can influence the ability of ectotherms to capture prey and/or defend themselves against predators. However, previous research on the kinematics of ectotherms suggests that some species may use elastic storage mechanisms when attacking or defending, thereby mitigating the effects of sub-optimal temperature. Rattlesnakes (Crotalus spp.) are a speciose group of ectothermic viperid snakes that rely on crypsis, rattling and striking to deter predators. We examined the influence of body temperature on the behavior and kinematics of two rattlesnake species (Crotalus oreganus helleri and Crotalus scutulatus) when defensively striking towards a threatening stimulus. We recorded defensive strikes at body temperatures ranging from 15–35°C. We found that strike speed and speed of mouth gaping during the strike were positively correlated with temperature. We also found a marginal effect of temperature on the probability of striking, latency to strike and strike outcome. Overall, warmer snakes are more likely to strike, strike faster, open their mouth faster and reach maximum gape earlier than colder snakes. However, the effects of temperature were less than would be expected for purely muscle-driven movements. Our results suggest that, although rattlesnakes are at a greater risk of predation at colder body temperatures, their decrease in strike performance may be mitigated to some extent by employing mechanisms in addition to skeletal muscle contraction (e.g. elastic energy storage) to power strikes.

scholarly journals Contrasting Responses of Lizards to Divergent Ecological Stressors Across Biological Levels of Organization

2019 ◽  
Vol 59 (2) ◽  
pp. 292-305 ◽  
Author(s):  
Rory S Telemeco ◽  
Dasia Y Simpson ◽  
Catherine Tylan ◽  
Tracy Langkilde ◽  
Tonia S Schwartz
Keyword(s):  
Stress Response ◽  
Cellular Response ◽  
Plasma Corticosterone ◽  
Cellular Level ◽  
Sceloporus Undulatus ◽  
Context Specific ◽  
Shock Proteins ◽  
Blood Glucose Concentrations ◽  
Red Imported Fire Ants ◽  
Generalized Stress Response

Abstract It is frequently hypothesized that animals employ a generalized “stress response,” largely mediated by glucocorticoid (GC) hormones, such as corticosterone, to combat challenging environmental conditions. Under this hypothesis, diverse stressors are predicted to have concordant effects across biological levels of an organism. We tested the generalized stress response hypothesis in two complementary experiments with juvenile and adult male Eastern fence lizards (Sceloporus undulatus). In both experiments, animals were exposed to diverse, ecologically-relevant, acute stressors (high temperature or red imported fire ants, Solenopsis invicta) and we examined their responses at three biological levels: behavioral; physiological (endocrine [plasma corticosterone and blood glucose concentrations] and innate immunity [complement and natural antibodies]); and cellular responses (gene expression of a panel of five heat-shock proteins in blood and liver) at 30 or 90 min post stress initiation. In both experiments, we observed large differences in the cellular response to the two stressors, which contrasts the similar behavioral and endocrine responses. In the adult experiment for which we had innate immune data, the stressors affected immune function independently, and they were correlated with CORT in opposing directions. Taken together, these results challenge the concept of a generalized stress response. Rather, the stress response was context specific, especially at the cellular level. Such context-specificity might explain why attempts to link GC hormones with life history and fitness have proved difficult. Our results emphasize the need for indicators at multiple biological levels and whole-organism examinations of stress.

Thermal biology of the spotted snow skink, Niveoscincus ocellatus, along an altitudinal gradient

2018 ◽  
Vol 66 (4) ◽  
pp. 235 ◽  
Author(s):  
Luh P. E. K. Yuni ◽  
Susan M. Jones ◽  
Erik Wapstra
Keyword(s):  
Body Temperature ◽  
High Altitude ◽  
Altitudinal Gradient ◽  
Thermal Environment ◽  
The Body ◽  
Activity Period ◽  
Lower Body ◽  
Body Temperatures ◽  
Mean Body Temperature ◽  
Thermal Biology

Body temperatures in ectotherms are strongly affected by their thermal environment. Ectotherms respond to variation in the thermal environment either by modification of behavioural thermoregulation to maintain their optimal body temperature or by shifting their optimal body temperature. In this study, the body temperatures of males of three populations of spotted snow skinks, Niveoscincus ocellatus, living along an altitudinal gradient (low, mid, and high altitude) were studied in the field and laboratory in spring, summer, and autumn, representing the full activity period of this species. The environmental variation across both sites and seasons affected their field active body temperatures. At the low and mid altitude, N. ocellatus had a higher mean body temperature than at the high altitude. Animals achieved their thermal preference at the low and mid altitude sites in all seasons. At the high altitude, however, N. ocellatus struggled to reach its preferred body temperatures, especially in autumn. The lower body temperature at the high-altitude site is likely due to limited thermal opportunity and/or an effect of avoiding the costs associated with increased intensity of basking.

scholarly journals Body Temperature and Reproductive Performance of Beef Heifers Supplemented With Rumen-Protected Methionine

2020 ◽  
Vol 8 (3) ◽  
pp. 601
Author(s):  
José Henrique Dominguez ◽  
Matheus Gomes Lopes ◽  
Fabrício Amadori Machado ◽  
Ederson Dos Santos ◽  
Fernanda Lopes ◽  
...  
Keyword(s):  
Body Temperature ◽  
Reproductive Performance ◽  
Fixed Time ◽  
The Body ◽  
Mineral Salt ◽  
Control Group ◽  
Lower Body ◽  
Body Temperatures ◽  
Beef Heifers ◽  
Data Logger

This study aimed to assess the reproductive performance and body temperature of beef heifers supplemented with rumen-protected methionine (RPM) in an extensive grazing system and mated during the summer. One hundred 5/8 Angus 3/8 Brahman heifers were homogeneously divided into the control group (n=48, CG) supplemented with mineral salt ad libitum and methionine group (n=52, MG) who received the same supplementation plus 4 g of methionine per 100 g of mineral salt. The groups were fixed-time artificial inseminated (FTAI) 45 days after starting the supplementation. On day 0 of the FTAI protocol, ten animals per group received data-logger thermometers attached in progesterone implants recording the body temperature of the animals every 30 minutes. Pregnancy diagnosis was performed on days 30 and 60 after the artificial insemination to determine the rates of conception, pregnancy, and pregnancy loss. At the beginning of the supplementation, both groups had similar weights (MG was 304.6 kg and CG 304.4 kg), while on days 0 and 30 about the FTAI protocol, the MG was higher weight (365.9 vs. 346.7 and 384.8 vs. 371.5 Kg). During the FTAI protocol, the MG had lower body temperatures (38.77 vs. 38.99 °C) and a tendency to have larger dominant follicles than the CG (11.76 mm x 10.8 mm). Although it did not impact reproductive performance, the observed higher weight, dominant follicle sizes, and lower body temperatures during FTAI protocols show the potential benefits of methionine supplementation in beef heifers mated during the summer.

scholarly journals Effects of Temperature on Anoplophora chinensis (Coleoptera: Cerambycidae) Adult Survival, Reproduction, and Egg Hatch

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 432 ◽  
Author(s):  
Melody A. Keena ◽  
Paul M. Moore ◽  
Gregg Bradford
Keyword(s):  
Invasive Species ◽  
Tree Species ◽  
Adult Survival ◽  
Optimum Temperature ◽  
Egg Hatch ◽  
Laboratory Conditions ◽  
Wide Range ◽  
Survival And Reproduction ◽  
Summer Temperatures ◽  
Effects Of Temperature

Anoplophora chinensis (Forster) is an invasive species that can damage many tree species in orchard, urban, and forested habitats. Adult survival, reproduction, and egg hatch of A. chinensis from Italy and China are evaluated at eight constant temperatures (5, 10, 15, 20, 25, 30, 35, and 40 °C) under laboratory conditions. The estimated Tmax for longevity was 42 and 33 °C for females and 42 and 39 °C for males from China and Italy, respectively. The estimated Tmax, Tmin, and optimum temperature for fecundity were 35, 9, and 29 °C, respectively. Females laid eggs at 15–30 °C and eggs hatched at 15–35 °C. Days to first oviposition increased exponentially from 13 days at 30 °C to >300 days near 10 °C. The estimated Tmin for egg hatch was 13 °C, the Tmax at 38 °C, and the optimum 29 °C. Percentage hatch was estimated to be highest at 26 °C and have a Tmax of 31 °C and Tmin of 10 °C. These results indicate that summer temperatures over a wide range of latitudes should support beetle survival and reproduction, but at temperatures ≥35 °C, oviposition ceases, and adult survivorship declines. In addition, females may survive into the fall, but lay fewer eggs that may not hatch. These responses of A. chinensis to temperature can be used for developing phenological models to predict the timing of stages for management or eradication efforts.

Body temperature regulation and oxygen consumption in young chicks fed thyroid hormone

1991 ◽  
Vol 69 (7) ◽  
pp. 1842-1847 ◽  
Author(s):  
Gregory K. Snyder ◽  
Joseph R. Coelho ◽  
Dalan R. Jensen
Keyword(s):  
Oxygen Consumption ◽  
Thyroid Hormone ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Cold Exposure ◽  
Elevated Serum ◽  
Body Temperatures ◽  
Serum Thyroid Hormone ◽  
Regulate Body Temperature ◽  
Young Chicks

In chicks the ability to regulate body temperature to adult levels develops during the first 2 weeks of life. We examined whether the ability of young chicks to regulate body temperature is increased by elevated levels of the thyroid hormone 3,3′5-triiodothyronine. By 13 days following hatch, body temperatures of chicks were not significantly different from those expected for adult birds. Furthermore, at an ambient temperature of 10 °C, 13-day-old control chicks were able to maintain body temperature, and elevated serum thyroid hormone levels did not increase rates of oxygen consumption or body temperature above control values. Six-day-old chicks had body temperatures that were significantly lower than those of the 13-day-old chicks and were not able to regulate body temperature when exposed to an ambient temperature of 10 °C. On the other hand, 6-day-old chicks with elevated serum thyroid hormone had significantly higher rates of oxygen consumption than 6-day-old control chicks, and were able to maintain constant body temperatures during cold exposure. The increased oxygen consumption rates and improved ability to regulate body temperature during cold exposure were correlated with increased citrate synthase activity in skeletal muscle. Our results support the argument that thyroid hormones play an important role in the development of thermoregulatory ability in neonate birds by stimulating enzyme activities associated with aerobic metabolism.

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