Monosodium Glutamate Effect on The Expression of alpha7nACHR and alpha4nACHR Subunits in The Testicular Tissue

Background: Monosodium glutamate (MSG) is a popular food flavor enhancer, and a glutamate subset that induces different toxicities such as hepatotoxicity, neurotoxicity, reproductive toxicity, and nephrotoxicity. This study was conducted to assess the effects of MSG on the & alpha;7 and & alpha;4 nicotinic acetylcholine receptor (nACHR) protein subunits expression of adult rat testis and the safety role of vitamin C. Materials and Methods: For this experimental research, 24 rats were haphazardly grouped into four equal groups (n=6) and orally gavaged for 30 days as follows: control group (distilled water gavage), MSG group (3 g/kg/b.w/ day), vitamin C group (150 mg/kg/b.w/day), and MSG+vitamin C group (3 g/kg/b.w/day+150 mg/kg/b.w/day, respectively) that rats of all groups on the 30th day were anesthetized, and the left testes were used for of & alpha;4 and & alpha;7 nACHR protein subunit evaluation by immunohistochemistry (IHC). Statistical computations were performed using Graph Pad Prism software. Results: The present study revealed a significant reduction in the expression and optical density (OD) of & alpha;7 nACHR and & alpha;4 nACHR in the seminiferous tubules and intertubular connective tissue in the MSG group compared to the control group. In the MSG+vitamin C group, the expression and OD of & alpha;7 nACHR and & alpha;4 nACHR increased in the seminiferous tubules and intertubular connective tissue but this improvement was not significant compared to the MSG group. Conclusion: MSG decreased the expression level of nACHR protein subunits, & alpha;7 and & alpha;4, in the seminiferous tubules and interstitial testicular tissue. Vitamin C in the MSG+vitamin C group could not significantly improve the expression of & alpha;7 and & alpha;4 nACHR subunits in testicular tissue. Probably, MSG toxicity can be compensated with higher doses of vitamin C.