The role of alpha1- and beta-adrenoceptors in initiation and development of thermoregulatory reactions during fast and slow cooling.

摘要

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.