Effect of bradykinin to cyclic AMP levels and response of murine lymphocytes.

No information is available on the pharmacological effect of bradykinin to lymphocytes and immunological responses of them. In this study it was clarified that bradykinin as well as histamine elevated cyclic adenosine 3',5' monophosphate (cAMP) levels of murine splenic or lymph node lymphocytes and mature thymocytes (cortisone-resistant thymus), but did not increase cAMP levels of immature thymocytes as well as histamine. The increased cAMP ratios in T cell-enriched splenic lymphocytes by the impulse of bradykinin were higher than that in splenic and lymph node lymphoid cells by the stimulation of bradykinin. It was also demonstrated that bradykinin as well as histamine suppressed DNA synthesis by mitogenic (PHA-P, Con-A) stimulation of splenic lymphocytes, but not a effect to the response of lymphocytes by mitogenic (LPS) stimulation was observed. These facts suggest that bradykinin may play an important role in the regulation of immunologic lymphocyte responses.