The Role of Growth Hormone in Regulation and Secretion of Ghrelin

Year 2013, Volume: 5 Issue: 2, 1 - 8, 01.12.2013

Basra Deniz Obay Hakkı Murat Bilgin Ezel Taşdemir Yaşar Yıldırım Abdurrahman Şermet Yüksel Koçyiğit

Abstract

Background: Ghrelin is a novel growth hormone (GH) releaser acylated peptide that has recently
been purified from stomach and potently binds to the GH secretagogue receptor. In rats, fasting
leads to elevated serum GH concentrations. Age-related decreases in energy expenditure have been
associated with the loss of skeletal muscle and decline of food intake, possibly through a mechanism
involving changes of GH secretion and feeding behavior. Ghrelin releases GH in vitro and in vivo
in animal models, however its actions and specificity in humans are unknown.
Method: We investigate the relationship between age-related changes of growth hormone secretion
and/or food intake and ghrelin function. Ghrelin (10 nmol/kg body weight) was administered
intravenously to male 3-, 12-, 24-and 27-month-old Wistar adult rats, after which growth hormone
concentrations and 2 h food intake were measured.
Results: Intravenous administration of ghrelin to rats increased food intake in all generations. In
addition ghrelin administration elicited a marked increase in plasma GH levels, with the peak
occurring 15 min after administration.
Conclusion: These changes in serum ghrelin concentrations during fasting were followed by
similar, profound changes in serum GH levels. These data indicate that ghrelin is the main driving
force behind the enhanced GH secretion during fasting.

Keywords

Ghrelin, growth hormon, food intake

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