The role of alpha1- and beta-adrenoceptors in initiation and development of thermoregulatory reactions during fast and slow cooling.
Ionophoretic application of alpha1- and beta-adrenoceptor blockers into the skin produces no effect on the parameters of thermal homeostasis under thermoneutral conditions. alpha1-Adrenoblocker verapamil inhibits cold shivering during fast and slow cold exposure; it elevates the temperature threshold and moderates the vasoconstrictor response during rapid cooling. These changes are accompanied by a compensatory decrease in the threshold and stimulation of non-shivering thermogenesis. Application of non-selective beta-blocker propranolol had no effect on the temperature thresholds of the thermoregulatory reactions, but augmented the maximum amplitude of shivering during both cooling protocols, thereby compensating the decrease in non-shivering thermogenesis. In the whole organism, block of one type adrenoceptors during cold exposure is accompanied by activation of the compensatory mechanisms mediated by adrenoceptors of the other type.
Tkachenko
E Y
EY
Department of Thermophysiology, Institute of Physiology, Siberian Division of the Russian Academy of Medical Sciences, Novosibirsk.
Gonzalez
E V
EV
Kozaruk
V P
VP
Kozyreva
T V
TV
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001833:Body Temperature Regulation / Q000502:physiology*; D003080:Cold Temperature; D008297:Male; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018340:Receptors, Adrenergic, alpha-1 / Q000502:physiology*; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D012881:Skin Temperature / Q000187:drug effects; D014700:Verapamil / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D018340:Receptors, Adrenergic, alpha-1; D011943:Receptors, Adrenergic, beta; D011433:Propranolol; D014700:Verapamil