Effects of growth hormone and prolactin immune development and function.

Growth hormone and prolactin are neuroendocrine hormones that exert numerous effects on immune system function and development. Several fundamental questions are addressed in this review. Do neuroendocrine hormones affect specific immune cell types? What is the physiological significance of these effects? Can these effects be exploited clinically? While it is clear that there are indeed significant interactions between the neuroendocrine and immune systems, there are relatively few examples with demonstrated physiological significance. Present studies indicate that growth hormone and prolactin may exert markedly different effects on immune cell types depending on their stage in differentiation. Recent emphasis has also been focussed on the use of these hormones or their antagonists clinically in the treatment of AIDS, cancer, and autoimmune disease states due to their pleiotropic effects and low toxicity after systemic administration. However, we do not yet have a clear picture of how the influence of neuroendocrine hormones may be used to favorably alter pathophysiologic processes affecting immune function and development.