TY - JOUR ID - 45378 TI - Orexin Decreases Aromatase Gene Expression in The Hypothalamus of Androgenized Female Rats JO - International Journal of Fertility and Sterility JA - IJFS LA - en SN - 2008-076X AU - Salimi, Maliheh AU - Alishah, Zahra AU - Khazali, Homayoun AU - Mahmoudi, Fariba AD - Department of Physiology, Faculty of Biological Sciences, Shahid Beheshti University, Tehran, Iran AD - Department of Biology, Facualty of Basic Sciences, University of Mohaghegh Ardabili, Ardabil, Iran Y1 - 2016 PY - 2016 VL - 10 IS - 2 SP - 190 EP - 195 KW - Orexin KW - Cyp19 KW - Female Rats DO - 10.22074/ijfs.2016.4909 N2 - Background Orexin is a hypothalamic orexigenic neuropeptide, which third cerebral injection of it mainly exerts inhibitory effects on reproductive functions. It increases significantly the Aromatase (Cyp19) gene expression in the hypothalamus of male rats. Aromatase is an enzyme which converts androgens to estradiol in the hypothalamus of rats. Prenatal or neonatal exposure of females to testosterone masculinizes the pattern of Cyp19 mRNA levels in adulthood. In the present study the effects of central injections of orexin-A on hypothalamic Cyp19 gene expression of adult female rats were investigated, while they had been androgenized on third day of postnatal life. Materials and Methods In this experimental study, twenty female Wistar rats received subcutaneous injections of testosterone propionate (50 µg/100 µl) on their third day of postnatal life. Adult androgenized rats weighing 180-220 g, received either 3 µl saline or one of 2, 4 or 8 µg/3 µl concentration of orexin via third cerebral ventricle. Five non-an- drogenized rats, as control group, received intra cerebral ventricle (ICV) injection of 3 µl saline. The hypothalamuses were dissected out and mean Cyp19 mRNA levels were de- termined by semi-quantitative real time-polymerase chain reaction (PCR) method. Data were analyzed by unpaired t test and one-way ANOVA using SPSS software, version 16. Results Mean relative Cyp19 mRNA level was significantly increased in the hypo- thalamus of androgenized compared to non-androgenized female rats. Central injec- tions of 2, 4 or 8 µg/3 µl orexin decreased significantly the hypothalamic Cyp19 mRNA level of androgenized rats compared to androgenized-control groups. Conclusion The results suggested that the orexin may exert inhibitory effects on the gene expression of Cyp19 in the hypothalamus of neonatal androgenized female rats in adulthood. UR - https://www.ijfs.ir/article_45378.html L1 - https://www.ijfs.ir/article_45378_c789a50a84d5019e96464e154fe9212f.pdf ER -