The effects of central ghrelin on serum parameters related to energy metabolism in neonatal chicks

BACKGROUND: Ghrelin is a regulatory peptide that has endocrine and metabolic effects in mammalian and birds.OBJECTIVES: The aim of this study was to investigate the possible effects of intracerebroventricular (ICV) injection of ghrelin on the plasma level of some hormones and biochemical indices that are involved in the energy balance of neonatal chicks. METHODS: Intracerebroventricular injection of 20 or 40 pmol ghrelin/individual was done and blood samples were collected from jugular vein, 15 and 30 minutes after the ICV injection ghrelin for measurement of serum parameters. RESULTS: The ICV administration of 20 and 40 pmol ghrelin/individual had no effects at 15 min post-injection, but at 30 min post-injection, the triiodothyronine (T3) level significantly decreased in a dose-dependent manner. The leptin level also declined significantly compared to that of the control group. There were no significant changes in other parameters, including insulin, T4, triglyceride, cholesterol and glucose. CONCLUSIONS: It can be concluded that the changes that occurred in T3 and leptin levels may have been due to the effects of ghrelin on the metabolic rate and food intake (with regard to T3) and the parallel action of ghrelin and leptin (with regard to leptin).