Effect Of GHRELIN On Cultured Cardiomyocytes Apoptosis Induced By High Glucose

【Objective】To investigate effect and mechanism of Ghrelin on hyperglycemia-induced apoptosis in cultured rat cardiomyocytes.【Methods】Cultured cardiomyocytes were randomly divided into 3 groups:Group N (cardiomyocytes were exposed to hypoglycemia type DMEM medium containing 15% FBS to continue to culture for 3 days (glucose level is 5.5mmol/L));Group H (After being cultured for 1 day in hypoglycemia type DMEM medium containing 15% FBS, cardiomyocytes were exposed to hyperglycemia type DMEM (glucose level is 25.0mmol/L)containing 15% FBS to culture for 2 days;Group G (After being pretreated 24 hours with Ghrelin( final concentration of 10-7mmol/L,each well added 50μl), cardiomyocytes were exposed to hyperglycemia type DMEM(glucose level is 25.0mmol/L)containing 15% FBS to continue to culture 2 days ).Apoptosis in different groups was determined by TUNEL.Change of caspase-3 activity in cardiomyocytes was detecetd by caspase-3 activity assay kit. RT-PCR was used to examine caspase-3 mRNA level in different groups.【Results】Compared with group N,the number of apoptotic cardiomyocytes was significantly increased in group H . The expression of caspase-3 in mRNA level and caspase-3 activity in group H was higher than that in group N(p<0.05).The number of apoptotic cardiomyocytes was significantly decreased in group G relative to group H.The expression of caspase-3 in mRNA level and caspase-3 activity in group G was markedly lower than that in group H.(p<0.05).【Conclusion】1.High glucose could make the expression of caspase-3 mRNA and caspase-3 activity increased,to cause a significant increase in apoptosis of myocardial cells.2.Ghrelin could inhibit hyperglycemia-induced apoptosis in cultured rat cardiomyocytes by decreasing the expression of caspase-3 mRNA and caspase-3 activity .