Effect of Alpha-2 adenoceptor inhibitors on the growth of ovarian follicles in patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common complex condition. Evidences from studies on women with PCOS and rat PCO model suggest that the sympathetic regulatory drive to the ovary may be unbalanced (hyperactivity). Findings that support the involvement of sympathetic nervous system in the pathophysiology of PCOS are that the catecholaminergic nerve fibers in the polycystic ovaries of women with PCOS are denser than in normal ovaries. The purpose of this study was reduction of this hyperactivity. This study was clinical trial and was performed in Reproductive Health Research Center, Tehran University of Medical Sciences, Iran, during January 2013 to 2015. A total of 61 women between aged 20-40 years and BMI under 28 kg/m2, who were previously diagnosed with PCOS were assessed. The diagnosis of PCOS was made according to joint criteria of the European Society of Human Reproduction and Embryology and the American Society of Reproductive Medicine (ESHRE/ASRM). The study objectives were explained to the patients before they entered the study, and an informed consent was obtained from all. They were divided into three groups as follows: (i) two study group (n=39) and (ii) control group (n=22). For evaluating effects of alpha-2 inhibitors (Clonidine and Yohimbine) by Eliza, the following variables were evaluated before and after drug therapy: serum cortisol adrenaline (A) noradrenalin (NA) beta-endorphin (&beta-End) insulin as well as sex hormones including FSH, LH and Estradiol. Our results showed that, Clonidine as central anti-adrenergic drug causes 61% of all pregnancies in the study group. This is high percentage of the pregnancy rate compared with yohimbine (P< 0.001). Yohimbine (Indol alkaloid) as alpha-2 adenoceptor antagonist increases follicular development in this disease. This follicle growth is higher than clonidine (P< 0.01). Our findings showed that increasing the pregnancy rate and follicular development represent the strategic role of sympathetic nervous system (SNS) in polycystic ovary syndrome and) SNS may thus offer a novel biological and pharmacological target in treatment of PCOS.