AIM:To study the changes of concentration of intracellular free calcium i) under hypoxia,and investigate the relieving effect of lycium barbarum glycopeptide(LbGp) on myocardial calcium overload induced by hypoxia and the protective effects of LbGp on the hypoxic cardiomyocytes. METHODS:Eighty neonatal rats of 2 or 3 days old were selected for culture of cardiomyocytes,and then made into models of myocardial ischemia. The rats were divided into control group, hypoxia group (cardiomyocytes under hypoxia for 6 hours) and LbGp group(50 mg/L LbGp was added,then hypoxia for 6 hours).The(i concentration of cardiomyocytes induced by ischemia was observed with the laser confocal microscope and the calcium fluorescent probe Flou 3/AM after loaded with Fluo/AM fluorescent indicator. RESULTS:After 6 hour hypoxia, there were fewer connection between cardiomyocytes,most of the cells became swelling,refraction was weaken,part of the cells even turned round, and the cellular membrane of a few cells were broken, indicating that there was myocardial injury.After hypoxia, cardiomyocytes in the LbGp group became swelling and had particles inside,refraction was weaken,but had the role of amelioration as compared with the hypoxia model group.
The results observed under laser confocal microscope after loaded with Fluo/AM showed that the distribution and outline form of cells were coincident with those observed under inverted microscope:the cells appeared irregular edges and multi angles,astrocyte, clear outline,spontaneous,synchronic and rhythmic beats were observed in the clustering cardiomyocytes.After Flu3 AM labeling,the cells appeared regular sparkling.The myocardial i fluorescent intensity and absorbance(A) in the control group were lower, and the fluorescent intensity after hypoxia for 6 hours was obviously increased(P< 0.05); the myocardiali fluorescent density was significantly lower in the LbGp group(62.86 ± 28.71) than in the hypoxia group(156.76± 55.39) (P< 0.01). CONCLUSION: LbGp can relieve the calcium overload induced by hypoxia.