Effects of N omega- Nitro-L-arginine methyl ester hydrochloride on nitric oxide synthase expression in rabbit sublingual glands

Abstract

Aim: In the present study, we investigated the expression of nitric oxide synthase in the rabbit sublingual glands and evaluated the effects of N omega-Nitro-L-arginine methyl ester hydrochloride (L-NAME) on NOS expression. Methodology: In order to identify the morphological characteristics of sublingual glands, histological analysis of HE staining was performed. Immunohistochemistry using monoclonal mouse anti-endothelial NOS and anti-neuronal NOS was performed oneday and three days after L-NAME treatment in the salivary glands of rabbits. Results: Endothelial NOS (eNOS) immunoreactivity was observed in the secretory duct system of sublingual gland of rabbit. L-NAME administration significantly decreasede NOS-positive immunoreactivities, but restored three days after L-NAME administration. Neuronal NOS (nNOS)-positive immunoreactivity was detected in the nerve fibers, however, unlike eNOSexpression, L-NAME administration did not significantly decrease nNOS immunoreactivity one day after treatment. Interpretation: The present study suggests that endogenous NOS is certainly present in sublingual glands of rabbits, and that the presence of eNOS and nNOS in the sublingual glands may be closely related with the actions of NO on regulating salivary secretion.