Investigation of the effect of diazinon on CatSper 1 gene expression, sperm motility and germinal epithelium thickness in adult male mice

Genetic changes and mutations in the genes involved in spermatogenesis can occur by environmental and congenital factors. Considering, the extensive use of diazinon in the farms and because we found no study on the effects of diazinon on the expression of CatSper1 gene, a key element of male fertility, we decided to perform this study in order to determine the effects of different doses of diazinon on CatSper1 gene expression, sperm motility and thickness of seminiferous tubules in adult male mice.

Twenty-four adult male Balb/c mice were randomly divided into four groups. The control group did not receive any injection. The sham group received diazinon solvent. Diazinon1 group received 7.5 mg/kg and, diazinon group 2 received 30 mg/kg of diazinon intraperitoneally, once a day for 2 weeks. After 35 days, we studied the sperms from the molecular and histological aspects and sperm motility was evaluated.

Sperm motility was significantly decreased in diazinon 1 (P-value = 0.001) and diazinon 2 (P-value = 0.001) groups compared to that in the control group. Gene expression in diazinon group 1 and diazinone group 2 (P-value = 0.002) was significantly lower than that in the control group. Histological examination also showed that diazinon treatment reduced germinal epithelium thickness and led to vacuole formation and degeneration. Epithelial thickness was significantly decreased in diazinon group 1 (P-value = 0.003) and diazinon group 2 (P-value = 0.006) in comparison to that in the control group.

Diazinon affects male fertility by reduction in sperm motility and degenerative changes in germinal epithelium. It also, decreases expression of CatSper1 gene, a key gene in fertility.