Nitric oxide synthase inhibitor reduces muscarinic-mediated depression of EPP values at the frog neuromuscular junction

Abstract

We investigated the role of nitric oxide (NO) in the modulation of muscarinic receptor-mediated depression of acetylcholine (ACh) release at the frog neuromuscular junction (NMJ). We activated muscarinic receptors at the frog NMJ using Oxotremorine-M (Oxo-M), a muscarinic agonist, in the presence and absence of N-?-Nitro-Larginine- methyl-ester (L-NAME), an NO synthase inhibitor. We found that Oxo-M depressed end plate potential (EPPs) values in the absence of L-NAME. However, we found that pretreatment with L-NAME eliminated this Oxo-M-induced depression at the frog NMJ.