AIM: To investigate the cardiac effects of ghrelin in rats with myocardial injury induced by isoprenaline (ISO).
METHODS: Forty healthy adult male albino rats weighting 180 – 200 gm were included in this study. The rats were randomly classified into 4 equal experimental groups; Group I (Control group):Received no medication and given free access to food and water. Group II (ghrelin group):Received Ghrelin (Gh) only in a dose of 10nmol/kg subcutaneous(S.C)for 2 days. GroupIII (isoprenaline group):Received single dose of isoprenaline (ISO) 75mg/kg intraperitoneal(i.p.)for induction of myocardial infarction (M.I).Group IV(ghrelin treated group):Received ghrelin in adose of 10 nmol/kg/day SC for 2 days before induction of myocardial infarction with ISO (as in ISO group).Thirty minutes after induction of M.I., a blood sample was collected from the right ventricle for estimation of plasma CK-MB, ghrelin and endothelin-1 levels and heart was excised for measurement of infarction size as percentage of left ventricle. RESULTS: About 20 % of rats after treatment with ISO alone died during experimental periods. However, no rats died after administration with ghrelin 10 nmol/Kg/d. Endothelin-1 and CK-MB level in plasma was decreased by ghrelin (10 nmol/kg) with significant reduction of the infarction size. Plasma ghrelin level was increased in the rats after ISO. The plasma ghrelin level was further increased after ghrelin administration.
CONCLUSION: Ghrelin has a protective effect against ISO-induced myocardial injury.