Investigation of the effects of vitamin d on the polycysticovary syndrome (PCOS) modeled rats

Polycystic ovary syndrome (PCOS) is a disease that is mostly seen in adolescent women and progresses with infertility. Despite its high incidence, its etiology and diagnostic criteria are still unclear. The lack of a specific treatment protocol for PCOS and its economic cost necessitate studies aimed at developing new diagnostic and treatment criteria. Our study aimed to investigate the biochemical and histopathological changes in the ovaries of PCOS model rats induced with Letrozole and the effect of Vitamin D (Vit D) on the immunohistochemical distribution of adipokines. In our study, 40 Spraque Dawley female rats (7 weeks old) were randomly divided into 5 groups as control group, Dimethyl sulfoxide group (DMSO), PCOS group, Vit D group and PCOS+Vit D group and the experimental period was determined as 21 days. Control group was made no other application except for food and water throughout the experiment. DMSO group was administered by oral gavage 2% DMSO throughout the experiment. PCOS group was administered by oral gavage letrozole at a dose of 1 mg/kg/day dissolved in 2% DMSO solution throughout the experiment Vit D group was administered by orally 200 IU/day Vit D throughout the experiment. PCOS+Vit D group was administered by oral gavage letrozole at a dose of 1 mg/kg/day throughout the experiment while was administered orally 200 IU/day Vit D simultaneously. At the end of the experiment, blood samples were taken from anesthetized rats by cardiac puncture. Ovarian tissues were taken from decapitated rats and routine tissue follow-up was performed. 5 micrometer (µm) thick sections were taken from ovarian paraffin tissue blocks for histopathological and immunohistochemical examinations. Histopathological findings and Omentin, Visfatin and Resistin immunoreactivity were determined from the obtained sections. Follicle XXI stimulating hormone (FSH), luteinizing hormone (LH), testosterone, interleukin-1 (IL-1), tumor necrosis factor-alpha (TNFα), insulin, glucose, homeostatic model assessment of Insulin Resistant (HOMA-IR) values were examined biochemically from blood samples. As a result of biochemical analysis; it was observed that FSH levels decreased, LH, testosterone, IL-1, TNFα, insulin, glucose levels and HOMA-IR values increased in the PCOS group. As a result of biochemical analyses, it was observed that FSH levels decreased and LH, testosterone, IL-1, TNFα, insulin, glucose levels and HOMA-IR values increased in the PCOS group. As a result of histomorphometric examinations, it was observed that the granulosa cell layer in secondary, tertiary and cystic follicles got thinner and theca follicle layer was thickened in the PCOS group. It was determined that the granulosa cell layer was thickened and the theca follicle layer got thinned in the PCOS+ Vit D group compared to the PCOS group. Histopathological examinations revealed a decrease of follicles in the developmental stages and numerous cystic follicle structures in the PCOS group compared with control, DMSO and Vit D groups. It was observed that cystic follicle structures were decreased and primary, secondary and tertiary follicle structures were more in the PCOS+ Vit D group compared to the PCOS group. According to the immunohistochemical histoscore results; it was observed that omentin immunoreactivity was lower, visfatin and resistin immunoreactivity was higher in the PCOS group compared to the control group. In the PCOS+ Vit D group, it was found that these values approached the control group values. In conclusion, it can be said that Vit D has positive effects on biochemical, histopathological and immunohistochemical changes seen in PCOS.