Cholinergic stimulation of RNA synthesis in rat lymphocytes.

In unstimulated lymphocytes acetylcholine caused concentration-dependent increase of RNA synthesis. Atropine and tubocurarine did not inhibit this stimulating effect, but, on the contrary, gave an additional peak of uridine incorporation. In lymphocytes stimulated previously with PHA, acetylcholine produced changes in RNA synthesis which did not depend on the dose of the mitogen. The stimulating effect of acetylcholine was inhibited at all concentrations by tubocurarine, while atropine abolished only the positive effects of higher acetylcholine concentrations. The results suggest occurrence of three different types of acetylcholine action on rat lymphocytes.