Lasting consistency of cold adaptability in rats reared in cold for many generations.
Wistar rats were successively reared in cold at 5 degrees C from 1969 to 1984. The historical changes observed in these rats were reported. The cold-adapted rats reared in cold for 8 to 11 successive generations (C8-11G) were examined on their cold tolerance and non-shivering thermogenesis. C8-11G rats showed greater nonshivering thermogenesis than that of the warm-adapted control group (W), and rats exposed to cold for periods of 2 to 8 weeks (C). The nonshivering thermogenesis of C8-11G rats was diminished to a similar level to that of W and C rats by administration of a ganglion blocker, of reserpine, or of beta-adrenoceptor blocker. The de-adapted rats reared in warm at 25 degrees C for 3 generations after being reared for many generations in cold (DA-3G) showed much more nonshivering thermogenesis as compared to W rats. Cold tolerance of DA-3G rats was at a level of intermediate between that of W and C rats. Brown adipose tissue (BAT) weight of DA-3G rats was similar to that of C rats, while chemical composition of BAT in DA-3G rats differed from that of C and W rats.
Moriya
K
K
Yahata
T
T
Kuroshima
A
A
D000222:Adaptation, Physiological; D002001:Adipose Tissue, Brown / Q000502:physiology; D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects; D003080:Cold Temperature; D005260:Female; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D006358:Hot Temperature; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D011247:Pregnancy; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012110:Reserpine / Q000494:pharmacology; D012768:Shivering; D013045:Species Specificity; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology
D006584:Hexamethonium Compounds; D018738:Hexamethonium; D012110:Reserpine; D011433:Propranolol; D009638:Norepinephrine