[Differences in the mechanisms of thermoregulation in rats in separate and combined adaptation to cold and heat]. / Razlichiia mekhanizmov termoreguliatsii krys pri razdel'noi i kombinirovannoi adaptatsii k kholodu i teplu.

Combined adaptation of rats to heat and cold increasing mechanisms of thermogenesis enhances resistance to both factors and heat dissipation. Adaptive changes in thermogenesis are mainly a result of activation of adrenergic mechanisms, while the separate cold adaptation is accompanied by hyperfunction of thyroid glands. Mechanisms of heat dissipation in rats of the "combined" group increase even more than those of "heat" group.

[Mechanisms of the thermogenic action of noradrenaline during adaptation to cold]. / O mekhanizmakh termogennogo deistviia noradrenaline pri adaptatsii k kholodu

In white rats both adapted and unadapted to cold, the RQ dynamics during cold exposure, noradrenaline and ganglion blocking agent administration, were studied. The adapted animals' RQ in thermoneutral conditions was shown to be a little higher than in the control rats; 0.5 mg/kg noradrenaline injections induced a clear RQ decrease in the former and did not influence the latters' RQ. Cold exposure was followed by a RQ decrease in both. Ganglion blocking agent administration decreased the RQ in the adapted animals and prevented it from falling in the control those. Noradrenaline is supposed to be the main but not the only factor activating lipolysis in the cold adapted animals.