Cyclic GMP stimulates lymphocyte nucleic acid synthesis

Abstract

AGENTS that trigger proliferation of lymphocytes¹ and other cultured cells² have also been reported to stimulate increases in intracellular guanosine 3′,5′-monophosphate (cyclic GMP). These observations raise the interesting possibility that endogenous cyclic GMP acts as the intracellular mediator of some of the effects of mitogenic agents: if so, then it might be possible to demonstrate experimentally that cyclic GMP, introduced exogenously, has a mitogenic effect. We tested this possibility in mouse splenic lymphocytes and compared the mitogenic effects of cyclic GMP and two of its synthetic derivatives, 8-bromo-cyclic GMP (8-Br cyclic GMP) and N² O²-dibutyryl-cyclic GMP (dibutyryl cyclic GMP), with that of concanavalin A (con A), a mitogenic lectin reported¹ to increase the cyclic GMP content of human lymphocytes. Our results indicate that, like con A, cyclic GMP and its derivatives can stimulate RNA and DNA synthesis in lymphocytes.