EFFECT OF GHRELIN ON MYOMETRIAL CONTRACTILITY IN PREGNANT AND NON-PREGNANT RATS Mohamad Yosof Rezk Physiology Department, Faculty of medicine, Zagazig University, Egypt
Background: Ghrelin is a 28 amino acid peptide hormone, discovered as being the endogenous ligand of growth hormone secretagogue receptor (GHS-R). Ghrelin is mainly produced by a subset of stomach cells and by the hypothalamus, the pituitary, and other tissues. Ghrelin exerts wide physiological actions throughout the body, including growth hormone secretion, appetite and food intake, gastric secretion and gastrointestinal motility, glucose homeostasis, cardiovascular functions, anti-inflammatory functions, reproductive functions, and bone formation. Aim: this study investigates the effect of ghrelin on myometrial contractility in both pregnant and non-pregnant rats. Methods: This work was carried out on 40 Adult female albino rats were divided into four equal groups (each 10 rats), Group I - Non pregnant-nonestrogen primed rats. Group II- non pregnant-estrogen primed rats. Group III- early pregnant rats (day; 7). Group IV- late pregnant rats (day; 18). Each group is subdivided into two subgroups: Subgroup 1, study the effect of ghrelin on spontaneous myometrial contractility. Subgroup 2: study the effect of ghrelin on oxytocin induced myometrial contractility. Results and conclusion: we found that ghrelin has a significant inhibitory effect on non-pregnant and pregnant uteri and this effect is modulated by hormonal milieu and decreased by the end of pregnancy. We suggested that ghrelin may play a role in the maintenance of uterine relaxation during pregnancy and this inhibitory effect on myometrial contractility is decreased at labor. Further studies on pharmacological modulation of the ghrelin effect on uterine muscle are recommended.