Zinat Sargari - M.Sc., Department of Basic Sciences, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran
Mohammad Reza Kikravesh - Ph.D.,Department of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Mehdi Jalali - Ph.D., Department of Anatomy and Cell Biology, School of Medicine, Mashhad University of MedicalSciences, Mashhad, Iran
Hamid Reza Sadeghnia - Ph.D., Department of Pharmacology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

Background: Diazinon (DZN) is an organophosphate insecticide that has been widelyutilized in agriculture all over the world and caused many negative effects on differentspecies such as plants and animal species, especially on a human.Objective: The aim of the present study was to evaluate the protective effect of vitaminE on rats’ ovarian follicles following an administration of diazinon.Materials and Methods: A total of 30 adult female Wistar rats were divided into fivegroups: a control group (without any intervention), sham group (received only pureolive oil, as solvent), experimental group I (DZN+olive oil, 60 mg/kg), experimentalgroup II (vitamin E, 200 mg/kg), and experimental group III (DZN: 60 mg/kg+vitaminE: 200 mg/kg). All drugs were injected intraperitoneally, except vitamin E which wasadministrated by gavage. The animals were scarified after two weeks and left ovary wasused to measure proliferation of ovarian follicles. Tissues were analyzed by the PCNAtechnique and viewed with an optical microscope for evaluating cells proliferation.Results: The result of the present study revealed that the number of proliferative cellsin the experimental group I decreased significantly in contrast to the control groupin secondary and Graffian follicles (p< 0.001). The administration of vitamin E plusDZN significantly increased proliferative cells compared to the DZN group (p< 0.001).Primordial follicles showed that all study groups were lacking PCNA positive cells,which means no expression of PCNA in these follicles. The results of this study showedthat primary follicles in all study groups had a few and scattered PCNA positive cellswith no significant difference between the groups (p> 0.05).Conclusion: Results showed that DZN reduced proliferation in secondary and Graffianfollicles and vitamin E increased it. The results of this study suggested that vitamin Eby its antioxidant activity was able to improve the DZN-induced ovarian toxicity.

Diazinon, Proliferation, Ovary, Vitamin E, Rat