Effect of Environmental Temperature on Reaction of Mice to Parathion, an Anticholinesterase Agent

1956 ◽  
Vol 186 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Anna M. Baetjer ◽  
Raymond Smith

Mice were exposed to three environmental temperatures, 60°, 73° and 96°F, for 3 days before and after intraperitoneal injection with an anticholinesterase, parathion. The onset of deaths, rate of dying and rate of recovery were more rapid, the survival time of the fatal cases was shorter, and the mortality was higher at 96° than at 73°F. At 60°F, the onset of deaths was delayed, and the final but not the early mortality exceeded that at 73°F. Somewhat similar, though less significant, differences occurred with intravenous injections. Experiments with different pre- and postinjection temperatures showed that mortality varied directly with pre- and inversely with postinjection temperatures and latent period varied inversely with preinjection temperatures. For comparison, acetylcholine and neostigmine were injected intraperitoneally in mice at these three temperatures. The rate of dying and mortality were only slightly greater at 96° than at 73°F. At 60°F the onset of deaths was delayed, the animals died more slowly and the mortality was significantly lower than at 73°F. The results cannot be attributed to acceleration of chemical reactions with changes in body temperature but appear to be due to variations in rate of absorption and other factors.

2020 ◽  
Vol 128 (4) ◽  
pp. 768-777
Author(s):  
Robert Shute ◽  
Katherine Marshall ◽  
Megan Opichka ◽  
Halee Schnitzler ◽  
Brent Ruby ◽  
...  

Cold environmental temperatures during exercise and recovery alter the acute response to cellular signaling and training adaptations. Approximately 3 wk is required for cold temperature acclimation to occur. To determine the impact of cold environmental temperature on training adaptations, fitness measurements, and aerobic performance, two groups of 12 untrained male subjects completed 1 h of cycling in 16 temperature acclimation sessions in either a 7°C or 20°C environmental temperature. Fitness assessments before and after acclimation occurred at standard room temperature. Muscle biopsies were taken from the vastus lateralis muscle before and after training to assess molecular markers related to mitochondrial development. Peroxisome proliferator-activated receptor-γ coactivator 1α ( PGC-1α) mRNA was higher in 7°C than in 20°C in response to acute exercise before training ( P = 0.012) but not after training ( P = 0.813). PGC-1α mRNA was lower after training ( P < 0.001). BNIP3 was lower after training in the 7°C than in the 20°C group ( P = 0.017) but not before training ( P = 0.549). No other differences occurred between temperature groups in VEGF, ERRα, NRF1, NRF2, TFAM, PINK1, Parkin, or BNIP3L mRNAs ( P > 0.05). PGC-1α protein and mtDNA were not different before training, after training, or between temperatures ( P > 0.05). Cycling power increased during the daily training ( P < 0.001) but was not different between temperatures ( P = 0.169). V̇o2peak increased with training ( P < 0.001) but was not different between temperature groups ( P = 0.460). These data indicate that a 3-wk period of acclimation/training in cold environmental temperatures alters PGC-1α gene expression acutely but this difference is not manifested in a greater increase in V̇o2peak and is dissipated as acclimation takes place. NEW & NOTEWORTHY This study examines the adaptive response of cellular signaling during exercise in cold environmental temperatures. We demonstrate that peroxisome proliferator-activated receptor-γ coactivator 1α mRNA is different between cold and room temperature environments before training but after training this difference no longer exists. This initial difference in transcriptional response between temperatures does not lead to differences in performance measures or increases in protein or mitochondria.


2021 ◽  
Vol 224 (3) ◽  
pp. jeb141309
Author(s):  
Danielle L. Levesque ◽  
Katie E. Marshall

ABSTRACTTemperature is an important environmental factor governing the ability of organisms to grow, survive and reproduce. Thermal performance curves (TPCs), with some caveats, are useful for charting the relationship between body temperature and some measure of performance in ectotherms, and provide a standardized set of characteristics for interspecific comparisons. Endotherms, however, have a more complicated relationship with environmental temperature, as endothermy leads to a decoupling of body temperature from external temperature through use of metabolic heat production, large changes in insulation and variable rates of evaporative heat loss. This has impeded our ability to model endothermic performance in relation to environmental temperature as well as to readily compare performance between species. In this Commentary, we compare the strengths and weaknesses of potential TPC analogues (including other useful proxies for linking performance to temperature) in endotherms and suggest several ways forward in the comparative ecophysiology of endotherms. Our goal is to provide a common language with which ecologists and physiologists can evaluate the effects of temperature on performance. Key directions for improving our understanding of endotherm thermoregulatory physiology include a comparative approach to the study of the level and precision of body temperature, measuring performance directly over a range of body temperatures and building comprehensive mechanistic models of endotherm responses to environmental temperatures. We believe the answer to the question posed in the title could be ‘yes’, but only if ‘performance’ is well defined and understood in relation to body temperature variation, and the costs and benefits of endothermy are specifically modelled.


2014 ◽  
Vol 35 (2) ◽  
pp. 161-172 ◽  
Author(s):  
Rafael Alejandro Lara-Resendiz ◽  
Tereza Jezkova ◽  
Philip C. Rosen ◽  
Fausto Roberto Méndez-de La Cruz

Reptiles in desert environments depend on habitat thermal quality to regulate their body temperature and perform biological activities. Understanding thermoregulation with respect to habitat thermal quality is critical for accurate predictions of species responses to climate change. We evaluated thermoregulation in Goode’s horned lizard, Phrynosoma goodei, and measured habitat thermal quality at the Reserva de la Biosfera El Pinacate y Gran Desierto de Altar, Sonora, Mexico, during the hottest season of the year. We found that field-active body temperature averaged 38.1 ± 0.38°C, preferred body temperature in laboratory averaged 34.9 ± 0.18°C and preferred body temperature range was 32.5-37.3°C. Operative temperature (i.e. environmental temperature available to the lizards) averaged 43.0 ± 0.07°C, with maximum temperature being near 70°C, and 62.9% of operative temperatures were above preferred body temperature range of P. goodei. Microhabitat thermal quality occupied by the lizards was high in the morning (7:00-10:30) and afternoon (5:50-dusk). We found that despite strong thermal constraints P. goodei was highly accurate and efficient in regulating its body temperature and that it presented a bimodal thermoregulatory pattern, being active in the mornings and in the evenings in order to avoid high mid-day environmental temperatures. Despite its thermoregulatory ability, P. goodei may be vulnerable to climate warming.


1963 ◽  
Vol 60 (2) ◽  
pp. 169-173 ◽  
Author(s):  
E. Eyal

1. A comparison was made between the pulse rate of shorn and unshorn sheep maintained in the shade and direct sunlight during the various seasons of the year.2. The variability of the pulse rate during the day generally agreed with the daily changes in body temperature and presumed level of metabolism. Fluctuations were greater in unshorn sheep.3. Pulse rate was lower during summer (60–100 for unshorn and 63–100 for shorn sheep) than in winter (90–130 for unshorn and 90–115 for shorn sheep). It tended to increase with a rise in ambient temperature, especially during winter and spring. A lower pulse rate accompanied a rise in environmental temperature, during summer. The slowest pulse rate of 42 per minute was observed during summer in the hot dry area.4. The pulse rate of both groups increased with a rise in rectal temperature, particularly at low ambient temperatures. At comparable rectal temperatures, a higher average pulse rate was observed in shorn sheep during winter and spring. With elevated summer temperatures, equal pulse rates were noted in both groups of equal rectal temperatures. Since the rectal temperatures of the shorn exceeded that of unshorn sheep, in high environmental temperatures, and in the sun, their pulse rate under these conditions was also higher.5. The differences in pulse rate between the two groups appeared to reflect the combined effects of metabolic rate, body temperature and the vasomotor activity, all of which vary with season and environmental temperatures.


1962 ◽  
Vol 42 (1) ◽  
pp. 1-8 ◽  
Author(s):  
C. B. Bailey ◽  
R. Hironaka ◽  
S. B Slen

Temperatures in the rumen, rectum, and subcutaneous tissues of four sheep receiving [Formula: see text] pounds of alfalfa hay per day were recorded at environmental temperatures of 15 °C. and −12 °C. The temperature of the drinking water was 20 °C. when the environmental temperature was 15 °C. and variously 0°, 10°, 20°, and 30 °C. during four different periods when the environmental temperature was −12 °C. At both environmental temperatures, the temperature in the rumen was higher than that in the rectum which, in turn, was higher than that in the subcutaneous tissues. The consumption of feed caused a transient increase in the temperature in the rumen and rectum while the consumption of water caused a transient decrease in the temperature in the rumen. A reduction in environmental temperature from 15 °C. to −12 °C. caused decreases in the temperatures in the rumen, rectum, and subcutaneous tissues, and reduced water intake from about 1600 to about 800 milliliters/day. At an environmental temperature of −12 °C., the temperature of the drinking water did not influence the amount of water consumed. It did, however, have an effect on body temperature because the average temperature in the rectum was slightly higher when the drinking water was 0 °C. than when it was 30 °C.


1936 ◽  
Vol 26 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Albert O. Rhoad

That extreme environmental temperatures have a marked influence on metabolism is a well-established fact. The early investigators, Kellner, Atwater, Armsby and others, studied the energy income and output of farm animals in relation to various conditions of the environment, and from these studies the principles of basal metabolism, critical temperature, and physical and chemical regulation of body temperature have evolved.


1955 ◽  
Vol 33 (1) ◽  
pp. 428-435 ◽  
Author(s):  
J. S. Hart ◽  
O. Heroux

Oxygen consumption and body temperatures were determined in lemmings at environmental temperatures from 20 °C. to −10 °C. and in rabbits from 20 °C. to −50 °C. Body insulation indices were estimated as the ratio [Formula: see text]. In both species, increase in activity and decrease in temperature led to increases in oxygen consumption that were additive over the temperature range. Oxygen increments of work were independent of environmental temperature in the absence of progressive hypothermia. Work led to increases in body temperature at the upper environmental temperatures and to decreases in body temperature at the lower temperatures. In extreme cold, rabbits became progressively hypothermic during work and there was a decline in oxygen consumption. Body temperatures started to fall at environmental temperatures 18 °C. higher in working than in resting rabbits. Insulation was lower in working than in resting animals. During exercise there appears to be a readjustment of body temperature, insulation, and heat loss until thermal equilibrium is established. The regulation of heat production, within limits, seems to be independent of body-temperature changes during exercise.


1960 ◽  
Vol 54 (3) ◽  
pp. 421-426 ◽  
Author(s):  
H. D. Johnson ◽  
A. C. Ragsdale

1. There were many distinct, consistent, individual differences in the thyroid activity of several of the animals used in this study. Graphic indications of breed differences were present at several high temperatures, and statistical analyses supported differences between the Jerseys raised at each temperature and the other two corresponding breeds. The Jerseys displayed higher rates. In no instances were there thyroid 131I release rate differences between Holsteins and Brown Swiss.2. There was a negative correlation between thyroid 131I release rate and temperature for each breed raised at each temperature. Correlations for the 50° F. animals were statistically significant below the 0·05 level of probability and for the 80° F. animals they were significant below the 0·01 level. As the environmental temperature increased from 35° to 80° F. there was a gradual decrease in thyroid 131I release rate. Above 80° F. there was a sharp decline in thyroid 131I activity.3. Within the range of environmental temperatures from 35° to 70° F. the animals raised at 80° F. displayed thyroid release rates higher than those of the animals raised at 50° F. At 80° and 90° F. the 50° F. Jerseys exhibited higher activity. The Jersey differences approached statistical significance. At the lower temperatures graphic differences between the Brown Swiss and the Holsteins raised at the two temperatures appeared to be present, but they were not generally supported by statistical analysis.4. At temperatures of 80° F. and above, when regulatory mechanisms could not control body temperature, both groups showed considerable rises in body temperature concomitant with decreases in thyroid 131I activity and TDN consumption. The 80° F. group showed a rise less sharp than that of the 50° F. group.


1955 ◽  
Vol 33 (3) ◽  
pp. 428-435 ◽  
Author(s):  
J. S. Hart ◽  
O. Heroux

Oxygen consumption and body temperatures were determined in lemmings at environmental temperatures from 20 °C. to −10 °C. and in rabbits from 20 °C. to −50 °C. Body insulation indices were estimated as the ratio [Formula: see text]. In both species, increase in activity and decrease in temperature led to increases in oxygen consumption that were additive over the temperature range. Oxygen increments of work were independent of environmental temperature in the absence of progressive hypothermia. Work led to increases in body temperature at the upper environmental temperatures and to decreases in body temperature at the lower temperatures. In extreme cold, rabbits became progressively hypothermic during work and there was a decline in oxygen consumption. Body temperatures started to fall at environmental temperatures 18 °C. higher in working than in resting rabbits. Insulation was lower in working than in resting animals. During exercise there appears to be a readjustment of body temperature, insulation, and heat loss until thermal equilibrium is established. The regulation of heat production, within limits, seems to be independent of body-temperature changes during exercise.


1963 ◽  
Vol 60 (2) ◽  
pp. 159-168 ◽  
Author(s):  
E. Eyal

1. The rectal temperatures of shorn and unshorn Awassi sheep were measured at various hours of the day and during various seasons of the year in two different locations in Israel.2. An increase in body temperature accompanied an increase in environmental temperature. A steeper temperature increase was noted in shorn sheep kept in the shade. When ambient temperatures were below 30° C. the body temperature of shorn sheep was lower than that of the unshorn sheep by an average of 0·16° C.3. When ambient temperatures were above 30° C. the body temperature of shorn sheep was equal to or higher than that of unshorn ones.4. Upon exposure to direct sunlight, the body temperature of shorn sheep exceeded that of unshorn animals. However, when the animals were transferred to the shade, or after sunset, the shorn sheep cooled at a faster rate. Their body temperature fell below that of the unshorn sheep during the cool hours of the day.5. Wind velocity, both in the shade and in the sun, had a greater effect on shorn than on unshorn sheep.6. A rise in the relative humidity of ambient temperatures above 25° C. caused body temperature to rise, particularly in unshorn animals. The body temperature of shorn sheep exceeded that of unshorn ones when the animals were maintained in a hot and dry environment.7. While the body of the shorn sheep was entirely affected by the macroclimate, the unshorn sheep were greatly influenced by the microclimate existing in the fleece. Fleece temperatures always lagged behind and were rarely equal to environmental temperatures. Since it was postulated that heat tolerance of certain animals was related to their ability to exploit cool hours of the day, it is suggested that in certain ‘tolerance tests’ records should be taken not only during exposure to heat but also during cool hours of the day.


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