Mouse growth hormone-releasing hormone (mGHRH) is synthesized by the hypothalamus, but is present also in the immune cells. Some recent data indicate also an immunomodulatory role of the neuropeptide. It can be examined that the influence of GHRH (1-44) on interleukin-6 and interleukin-8 secretion from human peripheral blood mononuclear cells cultured in vitro.