Letrozole and/or Fructose Induced‐Polycystic Ovarian Syndrome in Animal Model

Abstract

Polycystic ovarian syndrome (PCOS) is one of the most common causes of infertility among women, with about 10% of women affected in the general populace. The etiology of PCOS has not been fully elucidated; it is genetically based on ovarian disorder accompanied by excess production of androgen. The study was carried out to investigate in animal model Letrozole (L) and/or Fructose (F) induced polycystic ovarian syndrome using female Wistar rats. Ethical approval was obtained from National Institute for Pharmaceutical Research and Development (NIPRD) and the experiment conducted was in conformance with guidelines for experimental procedures as set forth in the Declaration of Helsinki and the APS Guiding Principals in the care and Use of Animals. Twenty virgin female rats were used and grouped into four groups of five rats each. Group served as the one control group, group two was treated with fructose (25% F mixed with 75% normal rodent diet), group three was treated with L (0.5mg/kg) and group four was treated with L and F. The experiment lasted for a period of 21 days. At the end of the experiment the animals were anesthetized with Thiopental (50mg/kg). Blood samples were obtained via cardiac puncture; sera obtained were analyzed for hormonal concentration of follicle stimulating hormone (FSH), luteinizing hormone (LH) and androgen (A) by ELISA technique. The ovaries, uteri and fallopian tubes were harvested and fixed in 10% formalin for histological evaluation. There was no significant increase in the % body weight in L and/or F treated rats compared with the control rats. Insignificant difference (p>0.05) in serum FSH was observed in groups treated with L (12.52±1.73 mIU/ml), F (11.22±1.76 mIU/ml) and L+F (11.72±1.83 mIU/ml) in comparison with their control counterpart (10.39±1.79 mIU/ml). However, insignificant differences were also observed in the serum levels of LH and A in L compared with the control group. The histological examination of the female reproductive organ (fallopian tube) of letrozole and/or fructose treated rats showed infiltration of inflammatory cells with severely congested epithelial cells and also hyperplasia of the tubular epithelial cells. Chronic intake of fructose and the use of letrozole in the treatment of cancer should be taken into consideration as both can cause imbalance in the level of androgen in females which was evident in the results obtained in our study.