Acetylcholine-induced initiation of thymic lymphoblast DNA synthesis and proliferation

Low (5 times 10-9 M to 10-7 M) acetylcholine concentrations cause a calcium-independent stimulation of the initiation of DNA synthesis and proliferation of lymphoblasts which are part of rat thymocyte populations suspended in vitro. A much higher (5 times 10-5 M) acetylcholine concentration also stimulates lymphoblast DNA synthesis and proliferation, but this action is calcium-dependent. This proliferogenic response to acetylcholine is however not clearly mediated by either cyclic GMP or cyclic AMP.