Effect of monosodium glutamate on the expression of α7nAchR and α4nAchR subunits in rat testis tissue: An experimental study

Document Type : Original Article


1 Department of Operating Room, Faculty of Paramedical Sciences, Gonabad University of Medical Sciences, Gonabad, Iran

2 Department of Anatomy and Cell Biology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

3 Department of Basic Medical Sciences, Neyshabur University of Medical Sciences, Neyshabur, Iran.



Background: Monosodium glutamate (MSG) is a popular food flavor enhancer, and a subset of glutamate induces different toxicities such as hepatotoxicity, neurotoxicity, reproductive toxicity, and nephrotoxicity. Mechanisms of MSG-Induced different toxicities are oxidative stress, lipid peroxidation, and decreased antioxidant activity. This study was conducted to assess the effects of monosodium glutamate on α7 and α4 nicotinic Acetylcholine Receptor (nAchR) subunits expression of adult rat testis and the safety role of vitamin C.

Materials and Methods: For this experimental research, rats were haphazardly distributed into 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). Rats received distilled water, MSG, and Vit C via oral gavage for 30 days. On day 30, the rats were anesthetized, and the left testes were used for immunohistochemistry (IHC) evaluation. In IHC, the brown color indicates the intensity of distribution of α4nAchR and α7nAchR subunits in testis tissue. For quantification, the severity of the brown color was converted to an optical density (OD).

Results: The study revealed a significant reduction in the expression and OD of α7nAchR and α4nAchR in the seminiferous tubules (p=0. 0.0017 and p=0.0031 respectively) and intertubular connective tissue (p=0.0025 and p=0.0009 respectively) in the MSG group compared to the control group. Vitamin C in the co-treatment group (MSG+ vitamin C) increased the expression and OD of α7nAchR and α4nAchR in the seminiferous tubules and intertubular connective tissue but this improvement was not significant compared to the MSG group.

Conclusion: Considering the vital role of 7nAchR and α4nAchR subunits in testicular tissue involved in germ cell differentiation, cell proliferation, and sperm transport, the decrease in the expression of these subunits following toxicity with MSG can be improved and restored by higher doses of vitamin C.


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