STIMULATION OF DNA SYNTHESIS AND MITOTIC ACTIVITY OF THYMIC LYMPHOCYTES BY CYCLIC ADENOSINE 3'5'-MONOPHOSPHATE

Physiological levels (10-8 to 10-6 M) of the cyclic nucleotide, adenosine 3′5′-monophosphate (cyclic AMP), were shown to promote deoxyribonucleic acid synthesis and mitotic activity in suspension cultures of rat thymic lymphocytes. Higher concentrations of cyclic AMP inhibited cell growth. It is concluded that cyclic AMP plays a central role in the control of cell division in thymocyte populations and could be the intracellular mediator of the mitogenic actions of a wide variety of hormones on this type of cell. © 1969.