ABSTRACT
A number of widely used organophosphorus compounds have been demonstrated to cause male reproductive system toxicity. Reports have been shown that the mechanisms of these adverse effects are still vague. These reports initiated the designation of the present study to compare and evaluate the potential gonadal toxicity of two different organophosphorus compounds, viz Parathion [dimethyl-O-4-nitrophenyl phosphothioate] and TOCP [Tri-O-cresyl phosphate]. Rats treated with TOCP 75 mg/kg/day for 7 weeks revealed almost cessation of sperm motility and dramatic disturbance in testicular cytoarchitecture, without significant alteration in plasma testosterone concentration. Regarding these parameters, Parathion 0.2 mg/kg/day for the same period showed no significant abnormalities, except for 20% decline in serum testosterone level compared to the control. This study confirmed the direct gonadal toxicity of TOCP, and demonstrated that it can not be attributed to androgenic mechanisms, or to depression of weight gain