[Estradiol valerate-induced polycystic ovary syndrome: an animal model study]

ABSTRACT

Polycystic ovary syndrome [PCOS] is a complex endocrine and metabolic disorder and one of the most common causes of an ovulation among women in their reproductive age. Presence of cysts in the ovaries alteration in the blood levels of gonadotropine hormones and gaining weight are some of the main characteristics of PCOS among humans. Our goal was to investigate the possible occurrence of such conditions in animal models of PCOS. Forty five Sprague Dawely rats were divided into 3 equal groups the treatment and sham groups were intramuscularly injected by a single dose of Estradiol Valerate [4 mg/rat, dissolved in 0.4 ml] and equal volume of olive oil, respectively, and the control group without any injection. During the 12 weeks of study, the animal's weights were measured once a week. After 8 weeks, serum levels of testosterone, estrogen, progesterone, Follicular Stimulating Hormone [FSH], Latinizing Hormone [LH] and glucose were measured. Following 12 weeks, ovaries were removed and prepared for light microscopy. Histological characteristics of ovaries were observed after hematoxylin-eosin staining. Animal weight and serum level of testosterone were significantly reduced among PCOS induced rats while progesterone, LH and glucose levels were elevated. There was no significant difference in estradiol and FSH levels among different group of animals. Many cysts and degenerating follicles were observed in the treatment group. PCOS can be experimentally produced by a single injection of Estradiol Valerate in the rat, but some of the complex aspects of PCOS are not clearly defined