[Efficiency of muscle work in white rats adapting to cold]. / Issledovanie éffektivnosti raboty myshts u belykh krys pri adaptatsii k kholodu.

The correlation between heat production and muscular work with loads from 50 to 500 g was studied in white rats adapted to cold.

[Sensitivity of skin cold receptors to noradrenaline in control and cold-adapted rats]. / Chuvstvitel'nost' kozhnykh kholodovykh retseptorov k noradrenalinu u kontrol'nykh i adaptirovannykh k kholodu krys.

I. a. administration of noradrenaline (NA) activated cold receptors both in control and in cold-adapted rats. Various doses of NA induced the receptors reaction of different duration. After adaptation to cold the sensitivity of receptors to NA increased. The data obtained suggest that the sympathetic systems and the receptors sensitivity to NA play an important role in static activity of the skin cold receptors.

[Work capacity of skeletal muscles and energetics of muscular work during adaptation to cold]. / Rabotosposobnost' skeletnykh myshts i énergetika myshechnoi raboty pri adaptatsii k kholodu

After the cold adaptation muscle contraction and the working capacity decreased. However, the muscles of the adapted to cold rats are able to save the initial power for a longer time. The muscular work of adapted to cold rats involves a greater expenditure of energy as compared with the control rats. Changes of the working capacity of skeletal muscles in control rats after noradrenalin administration are similar to those occurring in adapted to cold rats.

[Thermoregulatory effect of beta-adrenoreceptor block in the cold-adapted rat at rest and during exertion]. / Termoreguliatsionnyi éffekt blokady beta-adrenoretseptorov u adaptirovannykh k kholodu krys v pokoe i pri rabote.

Inderal does not affect the thermoregulatory system in thermoneutral conditions. Blockade of beta-adrenoreceptors at 6 degrees C decreases the oxygen consumption in cold-acclimated rats and reduces it down to the level of control animals. Cold-acclimated rats have the same level of work hyperthermia at different ambient temperatures (26 degrees C, 6 degrees C) and under inderal injection. Control animals can only the same in warm environment.