The NO synthase inhibitors L-Name and L-NMMA, but not L-arginine, block the mammalian nicotinic acetylcholine receptor channel

(1) Nitric oxide (NO) synthase inhibitors (NOS-I) such as L-Name (N-G-nitro L-arginine methyl ester) and L-NMMA (N-G-monomethyl L-arginine) may enhanc e anesthesia indirectly by inhibiting the NO pathway. Moreover, NOS-I inter act directly with receptor proteins. In an animal study, L-NMMA potentiated muscle relaxants. (2) The present experiments investigate the effects of L -NMMA, L-Name, and L-arginine on the nicotinic acetylcholine receptor chann el (nAChR) using patch clamp techniques and a piezo-driven application syst em. Both NOS-I appear to directly interact with the nAChR in the open as we ll as in the closed conformation. L-Arginine has no effect. (C) 1998 Elsevi er Science Ireland Ltd. All rights reserved.