Studies on cyclic AMP-cyclic GMP cooperation and on the influence of acetylcholine, adrenaline and thiols in lymphocyte reactivity.

In rat's lymph node lymphocytes, maximal stimulation of the response after suboptimal doses of PHA (1/2 of the optimal dose), measured by the incorporation of 3H-thymidine, after 10(-6) M acetylcholine and after 10 min interval between PHA and acetylcholine application was obtained. In these experiments inhibition of acetylcholine action by its muscarainic antagonists was not observed. It was shown that exogeneous cAMP as well as other factors, which increase cAMP level in lymphocytes had opposite effects to those, which could be caused by increasing of cGMP. Acetylcholine in optimal concentration (10(-6) M) as well as thiols, did not increase the level of endogeneous cAMP in rat lymphocytes.