LIMITATION OF STRESS REACTION INTENSITY UNDER THE CONDITIONS OF OPEN-FIELD TEST THROUGH RATS ADAPTATION TO COLD-EXPOSURE AND EXERCISE TRAINING

Male Wistar rats' adaptation to the periodical cold exposure (3 hours daily, 6 times a week within 2 months at the air temperature of 1-2-degrees-C) and to the exercise training (swimmimg 1 hour daily, 6 times a week within 2 months at the water temperature of 32-33-degrees-C) was resulted in a limitation of motional and vegetative manifestations of the stress reaction in the <<open field>> test. Activation of the stress limiting systems in the organism could be one of the main causes of these adaptive effects. There was an elevation of beta-endorphin concentration and that of the ratio <<prostacycline/thromboxane>> in some tissues of adapted animals.