:: Volume 14, Issue 1 (5-2012) ::
2012, 14(1): 81-87 Back to browse issues page
Effects of Testosterone and Growth Hormone on Plasma Concentrations of Orexin in Diet Restricted Rams
Fatemeh Davari , Homayoon Khazali , Hasan Rokni , Zahra Fatehi
Shahid Beheshti University , fatemeh2665@yahoo.com
Abstract:   (30622 Views)
Introduction: It has been established that multiple neuroendocrine factors such as orexin operate as metabolic signals for the reproductive tract. Since the effects of testosterone and growth hormone on concentration of orexin in rams have not been studied, the goal of this study was to determine the effect of testosterone and growth hormone on mean plasma concentrations of orexin in rams fed restricted diets. Materials and Methods: Rams were randomly divided into 2 groups. Animals in first group were fed 100% of their required daily food and those in the second group were fed 50% of food fed to the first group for 10 days. Consequently, the rams in all groups received 6μg /Kg BW testosterone on days 7 and 8 and 6μg /Kg BW Testosterone and 5 μg /Kg BW growth hormone on days 9 and 10 of the experiment. Blood samples were collected from the jugular veins at -120 and +120 minutes of infusions. for orexin assay, Plasma orexin were measured by a homologous double-antibody radioimmunoassay (RIA). Results: Injection of different dosages of testosterone and combination of testosterone and growth hormone in the 50%-diet, significantly (P<0.05*) increased the mean plasma concentrations of orexin, while in the 100%-diet this had no effect. Conclusion: Results indicate that testosterone and growth hormone may increase mean concentrations of orexin in animals fed lower than their daily food requirement.
Keywords: Orexin, Testosterone, Growth hormone, Food restriction, Rams
Full-Text [PDF 291 kb]   (6025 Downloads)    
Type of Study: Original | Subject: Endocrinology
Received: 2011/10/16 | Accepted: 2011/12/24 | Published: 2012/05/15


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Volume 14, Issue 1 (5-2012) Back to browse issues page