Ambient temperature effect on changes in heat exchange and skin and coat thermoisolation induced with nembutal in guinea pigs.
The experiment was carried out on adult male guinea pigs not adapted to cold at temperatures of 29 degrees, 20 degrees and 12 degrees C. During 150 minutes after nembutal injection the following values were recorded: oxygen consumption, subcutaneous, cutaneous and hair-coat temperatures. Using Hatfield's disc heat loss from the body surface by radiation and convection was measured. Nembutal not only inhibited thermogenetic processes at low ambient temperature, but decreased also heat production in a thermoneutral environment. This effect increased with decreasing ambient temperature. At the same time, there was a reduction in heat loss, although in a lower degree. The final result was a fall of the rectal temperature (even by 10 degrees C in a cold environment). Following nembutal administration skin thermoinsulation decreased slightly but the thermoinsulating activity of the hair-coat increased (the pilomotor response was more pronounced than in waking animals). Thermoregulation disturbances induced by nembutal included mainly thermogenesis impairment. The effect of general anaesthesia on heat loss was without any greater importance for maintenance of thermic homeostasis of the organism.
D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects; D003080:Cold Temperature; D003864:Depression, Chemical; D006168:Guinea Pigs; D006197:Hair / Q000502:physiology*; D007036:Hypothermia, Induced; D008297:Male; D010424:Pentobarbital / Q000494:pharmacology; D012881:Skin Temperature / Q000187:drug effects
D010424:Pentobarbital