CHANGES IN SOME PARAMETERS OF THE IMMUNE-RESPONSE IN RATS AFTER COLD STRESS

The influence of stress upon the endocrine system and its relationship to the immune system have been studied. The simulation of chronic col d stress in rats caused an increase in ACTH, corticosterone, and T-3 a nd T-4 levels. The different hormonal background in stressed animals a ffected the characteristics and the intensity of the immune response, which was traced in dynamics and through the action of 10(9) ovine ery throcytes. A strong suppression of B-lymphocytes and of PFC count was observed. Increased Fc gamma-RFC-suppressing activity was also determi ned. The PFC suppression changed simultaneously with the rate and dyna mics of Fc gamma-RFC-suppressing activity in animals under stress. In control rats (immunized with ovine erythrocytes only), the antigen cau sed insignificant changes in corticosterone level, which was not typic al for stress and was not accompanied by suppressing activity in the i mmune response.