IDENTIFICATION OF NICOTINIC ACETYLCHOLINE-RECEPTORS ON LYMPHOCYTES INTHE PERIPHERY AS WELL AS THYMUS IN MICE

The existence of nicotinic acetylcholine receptors (nAChR) on lymphocy tes remains controversial. We attempted to show the existence of nAChR on murine lymphocytes. The intraperitoneal injection of nicotine indu ced the lymphocytosis in the spleen on day 3. Although freshly isolate d lymphocytes bound small quantities of fluorescein isothiocyanate (FI TC)-conjugated alpha-bungarotoxin (alpha BuTx), they began to bind alp ha BuTx after incubation in medium. In contrast to granulocytes, vario us lymphocyte subsets obtained from various lymphoid organs were found to bind alpha BuTx. Affinity purification of alpha BuTx-binding prote in revealed that lymphocytes expressed the same nAChR molecules as tho se of muscle. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that lymphocytes expressed the alpha-subunit mRNA of nAChR. These results suggest that lymphocytes carry nAChR on the surfa ce and are stimulated directly via their nAChR by parasympathetic nerv e stimuli.