Aim: 

Cypermethrin and trifluralin are widely used synthetic pyrethroid insecticide and herbicide, respectively. We have investigated their effects on serum levels of testosterone, luteinising hormone (LH) and follicle stimulating hormone (FSH) levels and weights of androgen-sensitive tissues in peri-pubertal male rats using Hershberger assay.

Methods: 

Male Sprague-Dawley rats (42-day old) were used. First group was sham-orchidectomized. The remaining rats were orchidectomized and then divided into five groups: Group II (orchidectomy), Group III (testosterone propionate, TP, 0.5 mg/ kg/day sc), Group IV (TP+flutamide, reference anti-androgen), Group V (TP+Cypermethrin; 20 mg/kg/day, oral gavage) and Group VI (TP+Trifluralin, 15 mg/kg/day, oral gavage). All drugs were administered for 10 days, and animals decapitated 24h after the last injections. Prostate gland, seminal vesicles and m. levator ani (mLA) were weighed out. Serum levels of testosterone, LH and FSH were determined by ELISA.

Results: 

Serum levels of testosterone were significantly reduced in orchidectomy and flutamide groups (p < 0.001). Serum LH and FSH levels were significantly increased by both trifluralin and cypermethrin (p < 0.05). Flutamide significantly increased serum gonadotrophin levels and decreased weights of androgen sensitive tissues compared to sham or TP groups (p < 0.01). Weights of prostate (p < 0.05; except cypermethrin group), seminal vesicles (p < 0.01) and mLA (p < 0.01) were significantly reduced by both pesticides.

Conclusion: 

These findings indicate that both cypermethrin and trifluralin produced anti-androgenic effects in pre-pubertal rat model using Hershberger assay. We suggest that these pesticides may cause endocrine disruptive effects. Supported by TUBITAK (project # 104-T-240).