Aim: To evaluate the joint action of phoxim and fenvalerate on the reproductive function in male Sprague-Dawley rats.
Methods: The 2 x 2 factorial analysis experiment was used in the study. The pesticides were orally given at daily doses of phoxim (Pho) 8.2 mg/kg, fenvalerate (Fen) 3.3 mg/kg and Pho 8.2+Fen 3.3 mg/kg (Pho:Fen = 5:2), 5 days a week for 60 days. Sperm motility was measured with computer-assisted sperm motility analysis (CASA) and daily sperm production estimated. Immunoenzymatic method and electron microscopy were used to evaluate the serum testosterone and the testicular morphology, respectively.
Results: There were significant decreases in sperm motility parameters in the treated animals, including straight line velocity (VSL), beat cross frequency (BCF), linearity (LIN) and straightness (STR). After treated with Fen, significant decreases in VSL, LIN and STR were demonstrated. Significant decreases of daily sperm production were seen in animals treated with Pho and Pho+Fen in comparison with the controls. Serum testosterone levels were not significantly changed in the treated groups. Factorial ANOVA showed that no significant interactions were noted between Pho and Fen in sperm motility, sperm production and serum testosterone. Both the single and mixed pesticides caused various degrees of testicular lesions, involving vacuolation of endoplasmic reticulum and necrosis of Sertoli cells.
Conclusion: The pesticides may cause sperm motility changes and testicular lesions in male rats. The action of Pho and Fen may be additive.