Changes in hypothalamic noradrenaline and 5-hydroxytryptamine levels during the development of warm- and cold-adaptation in the rat.
Hypothalamic 5-hydroxytryptamine (5-HT) and noradrenaline (NA) as well as plasma corticosterone levels were studied in male rats after 1, 2, 4 and 6 weeks of exposure to 4--7 or 30--31 degrees C. An increase of the NA concentration and a decrease of the 5-HT level was observed after the first week in both cold and warm environment together with an increase of plasma corticosterone levels in both groups. NA, 5-HT and plasma corticosterone levels returned to normal in cold-exposed animals by the 6th week whereas in warm-acclimated rats NA and corticosterone levels regained their initial values and 5-HT concentrations remained low. Changes by the end of the first week of exposure may result from the thermal stress. The low 5-HT levels of warm-adapted animals at the end of the 6th week were probably secondary to the process of adaptation.
D000222:Adaptation, Physiological; D000818:Animals; D003080:Cold Temperature; D003345:Corticosterone / Q000097:blood; D006358:Hot Temperature; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D012701:Serotonin / Q000378:metabolism*
D012701:Serotonin; D003345:Corticosterone; D009638:Norepinephrine