Ghrelin is a growth hormone secretagogue that plays an important role in appetite and weight regulation. We have previously demonstrated that central ghrelin stimulated pituitary ACTH synthesis and secretion. In this study we further examined the effects of intracerebroventricular (ICV) ad-mi-nistration of ghrelin on zona glomerulosa (ZG), zona fasciculata (ZF) and zona reticularis (ZR) of the adrenal cortex, as well as the blood concentrations of aldosterone, corticosterone and dehydroepiandrosterone (DHEA) in male rats. Rats received 1.0 μg of ghrelin dissolved in 5.0 μg of PBS ICV, whereas control rats received only ICV PBS, during five consecutive days. The rats were decapitated 2 h after the last ICV ghrelin injection. Blood samples were collected from each rat for hormonal analyses, while adrenal glands were excised and prepared for further histological and morphmetrical measurements. Ghrelin treatment significantly increased (P<0.05) body weight by 13% compared to controls. Absolute weight and volume of whole adrenal glands were significantly (P<0.05) increased by 17.9% and 19.7%, respectively, in comparison with control values. The absolute volume of adrenal cortex, zona glomerulosa, zona fasciculate and zona reticularis were also significantly (P<0.05) increased by 20.3, 20.9, 21.4 and 11.1%, respectively, in comparison with the corresponding controls. Serum concentrations of the aldosterone, corticosterone and DHEA were significantly (P<0.05) increased by 32.3, 66.5, and 28.0%, respectively. These re-sults indicate that central ghrelin acts stimulatory on growth and secretory function of all adrenocortical zone cells of adult male rats.
25 - 29 Apr 2009
European Society of Endocrinology