Selective display of histamine receptors on lymphocytes.

Histamine, acting on histamine type 2 receptors, increases intracellular cyclic adenosine monophosphate (AMP) and thus modulates the immunologic functions of lymphocytes. Lymphocyte cyclic AMP levels were used to follow the development of histamine receptors. The B lymphocytes have no functional histamine receptors. As T lymphocytes "mature" in immunologic function--from thymocytes to cortisone-resistant thymocytes to splenic T lymphocytes--their response to histamine increases. The response of these subpopulations of lymphocytes to isoproterenol is the inverse of the histamine response. It is suggested that the changing display of histamine receptors plays an important part in the control of immunologic responses.