Nicotinic acetylcholine receptor: evidence for a functionally distinct receptor on human lymphocytes

The presence of three distinct cholinergic receptors on human lymphocytes was suggested by the effects of carbamoylcholine on lymphocyte proliferation in vitro. The cells responded to both 0.1 nM and 1 microM carbamoylcholine by increased proliferation which was blocked by the muscarinic antagonist atropine. This effect occurred in both mitogen-stimulated cells (maximum effect at 24 hr) and nonstimulated cells (maximum effect at 72 hr). In contrast, 1--10 nM carbamoylcholine produced diminished in vitro proliferation, an effect which was blocked by the nicotinic antagonists alpha-bungarotoxin and d-tubocurarine.