The Effect of Ghrelin and Morphine on mean concentration of Thyroid hormones

Ghrelin is a novel peptide hormone that has GH releasing activity and also other endocrine and metabolic functions. It can also increase food intake and decrease T۳ and T۴ concentrations. Several parameters of hypothalamic-pituitary-thyroid (HPT) axis function are modulated by morphine. The purpose of this study was to investigate the effect of interactions between ghrelin and morphine (injected via ICV route) on plasma T۳ and T۴ concentrations in female rats. Eighteen Wistar female rats (bodyweight, ۲۰۰-۲۵۰ g) were randomly divided into three groups. Group ۱ received Morphine, Group ۲ received Ghrelin and Group ۳ received ghrelin and morphine. Plasma samples were used to assess T۳ and T۴ concentration by RIA. The results indicated that ghrelin significantly decreased thyroid hormone concentrations, and also morphine decreased these concentrations. The simultaneous injection of ghrelin and morphine significantly decreased the thyroid hormone concentrations but Shows less reduction than the two individual effects (P < ۰.۰۵) According to the results of this study, both Ghrelin and morphine affect the concentration of thyroid hormone is decreased. Ghrelin increases dopamine. Morphine also increases Dopamine. Dopamine is a common mechanism in the downregulation of Ghrelin and opioid peptides in the control of thyroid hormone secretion.

کلیدواژه ها:

Ghrelin ، morphine ، Injection