Toxic effects of ketamine on reproductive system via disrupting hypothalamic-pituitary-testicular axis.

OBJECTIVE: In this paper, we focused on the toxic effect of ketamine on the reproductive system in male rats and its underlying mechanisms. MATERIALS AND METHODS: Rats were randomly allocated into four groups (n=10), i.e. a control group and 3 ketamine groups (high-dose, mid-dose, low-dose). Animals in the ketamine groups received an intraperitoneal injection of ketamine (20, 40 or 60 mg/kg) every 3 days for 7 times. Control rats were injected with normal saline instead. To investigate the disruption potential on the hypothalamic- pituitary-testicular (HPG) axis, the relative hormone levels in serum and mRNA expressions for some reproduction-related genes in reproductive organs were evaluated. RESULTS: Ketamine significantly decreased the serum concentrations of testosterone (T), inhibin B, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Meanwhile, the mRNA expressions of GnRH in the hypothalamus, GnRH receptor, LH-beta and FSH-beta in the pituitary, and LH receptor and FSH receptor in testes were also significantly inhibited by ketamine compared with the control (p < 0.01). CONCLUSIONS: These results demonstrated that the ketamine had a toxic effect on the reproductive system via breaking the HPG equilibrium.