[Ca(2+) level in the animal blood and their cold resistance]

Administration of small doses of the EDTA decreased by 15-20% the Ca2+ contentn in the blood plasma of rabbits and rats. The decrease coincided with an abrupt stimulation of the thermoregulation system of cooled animals. Restoration of the Ca2+ content in circulating blood coincided in time with repeated suppression of the system's functions. The findings corroborate the theory of a key role of the Ca2+ in sensitivity of the homoiothermal organism to cold and substantiates the method of restoring physiological functions in deep hypothermia without rewarming the body.