PARTICIPATION OF HORMONE IN THE EARLY STAGES OF THE IMMUNE RESPONSE

Immunization of weanling rats with sheep erythrocytes leads within 24 hours to an increase in DNA synthesis in the spleen but not in the lymph nodes. Growth hormone, insulin and oestradiol, given together with the antigen, increase the response of the spleen to antigenic stimulation, and initiate a pronounced increase in DNA synthesis of the lymph nodes in response to antigen. On the other hand, thyrotrophin reduces the rate of DNA synthesis in spleen and in lymph nodes following antigenic stimulation. When administered singularly, only growth hormone and insulin increase DNA synthesis in spleen, but not in lymph nodes.It is suggested that growth hormone, oestradiol, or insulin are involved in the proliferative response of lymphoid organs following an antigenic stimulation.