Gene expression of insulin receptor in the hypothalamus of female rat in model of polycystic ovary syndrome induced by sexual steroids

• Grant number: 12/07764-3
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): September 01, 2012
• Effective date (End): August 31, 2013
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Gustavo Arantes Rosa Maciel
• Grantee: Daniele Coelho Duarte
• Home Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Polycystic ovary syndrome (PCOS) is a complex disorder of unknown etiology, which is the leading cause of female infertility. It is characterized by hyperandrogenism, amenorrhea and the presence of polycystic ovaries. Regarding the hormonal profile typical of the syndrome, it displays a predominance of the secretion of luteinizing hormone (LH) in relation to follicle-stimulating hormone (FSH), and suggests that this observation is due to a dysregulation of the hypothalamic -pituitary-gonadal axis. This axis is in turn subject to various regulatory processes, either through the mechanism of negative feedback exerted by gonadal hormones produced under gonadotropin stimulation, either through other biological mediators - such as kisspeptins, beta-endorphins and dopamine. Another factor for regulation of this axis, and that has been gaining momentum, is insulin, the hormone that stands out primarily for their roles in energy metabolism. With regard to reproductive functions, we highlight the role of insulin receptors in the central nervous system, stimulating the release of GnRH from the hypothalamus by specific neurons. This research project aims to evaluate the expression of these receptors for insulin in animal models to SOP. The experimental design includes 30 female rats treated with subcutaneous injection on days 0 to 3 of age. The animal were divided into three groups according to the administered compound: testosterone, which is given 1.25 mg of testosterone propionate (n = 10), estradiol, where will be administered 0.5 mg of estradiol benzoate (n = 10), and control, where it is administered vehicle alone (n = 10). Upon reaching 90 days of age, the animals are sacrificed and the hypothalamic is removed, to be used for analysis of expression of insulin receptors by quantitative PCR Real Time. Statistical analysis will be carried out using analysis of variance (ANOVA) with the multiple comparison test by Tukey-Kramer.