Muscarinic cholinergic activation of mouse spleen cells cytotoxic to tumor cells in vitro.

Carbamylcholine, acting via a pharmacologically specific receptor, had the ability to activate effector populations of spleen cells from female BALB/cfC3H and BALB/c mice; those cell populations were then significantly reactive in vitro against syngeneic tumor target cells but were only minimally reactive to normal syngeneic target tissues. The induced reactivity was inhibited by the muscarinic cholinergic antagonists atropine, scopolamine, and isopropamide, but not by the nicotinic antagonist d-tubocurare, and it appeared to involve both T-cell and non-T-cell effectors.