Study on the effects of nano zinc oxide on oogenesis of adult NMRI mouse strain

Increase in the use of nano zinc oxide in medicine، manufacturing cosmetic products and research، have raised the questions about their toxicity. Zinc has direct role in growth، maturation and ovulation through influence on production of estradiol and progesterone. In this study the effects of nano zinc oxide on oogenesis of adult NMRI mouse strain have been investigated. The adult female mice were randomly divided into six groups، including control، sham and four experimental groups. Experimental groups were injected nano-ZnO (50-100-150-300 mg/kgbw) Intraperito-neally، respectively for 3 days. After 7 day، histological changes of ovaries were studied. Data indicated increase of numbers of Graafian follicles and corpora lutea in 100 and 150 mg/kg bw doses. Increase in estradiol and progestron levels with increase on dose was observed. Data indicated increase of numbers of atretic follicles with decreased body weight in higher doses. Results indicated oogenesis under 100 and 150 doses nano-Zno has improved with enhancing the number of Graafian follicles and corpora lutea، and decrease of body weight and increase of number of atretic follicles under higher doses. The results also indicated that nano-Zno has toxic effects on reproductive organs in female animal.