Objective To explore the role of potassium channel in cardiomyocyte apoptosis induced by ischemia/reperfusion process. Methods Cell viability,caspase-3 activity,intracellular reactive oxygen species(ROS)levels and cell membrane integrity were observed in apoptotic model of mouse cardiomyocytes induced by ischemia/reperfusion(I/R).Experiment groups included negative control,positive control(I/R)and drug treatment group(I/R + potassium channel blocker).Results (1)Potassium channel blockers potently inhibited cardiomyocyte apoptosis induced by I/R.Cell viability in Quinine(81.1%)and BaCl2(82.3%)groups were higher than in positive group (52.1%)(all P＜0.01).(2)Compared with positive control group(482.3%),potassium channel blockers(188.3% in Quinine group and 191.4% in BaCl2 group)inhibited caspase-3 activity significantly 24 hours after reperfusion(P＜0.01).(3)In both positive control and drug groups,the cell lactate dehydrogenase(LDH)leakage was less than 10% at 96 hours after reperfusion.Conclusions Potassium channel blockers can protect injured cardiomyocyte by inhibiting caspase-3 activity and ROS production in I/R process.

AIM:To investigate whether the chloride/bicarbonate (Cl-/HCO-3) exchanger is involved in staurosporine (STS) induced mouse cardiomyocyte apoptosis,and further understand the function of Cl-/HCO-3 exchanger in cell apoptosis. METHODS:To induce mouse cardiomyocyte apoptosis and to explore the effect of Cl-/HCO-3 exchanger,STS was used with two methods:⑴ different blocker,the chloride channel as well as exchanger blocker DIDS and the chloride channel blocker NPPB; ⑵ different culture medium with or without HCO-3 component. RESULTS:The cell viability and caspase-3 activity of DIDS and NPPB on STS-induced cardiomyocyte apoptosis were 59.7% and 47.2%,175.0% and 212.0% respectively with significant statistic differences (both P0.05,n=20). The cell viability and caspase-3 activity of STS-induced cardiomyocyte apoptosis in culture medium with or without HCO-3 were 29.8% and 41.6%,553.4% and 424.7%,respectively (both P

Objective By analyzing the clinical symptoms, heart rate ( HR) , arterial oxygen saturation ( SaO2 ) and the number of white blood cells (WBC), we aimed to explore the implication of the above-mentioned indexes for early warning of high altitude pulmonary edema ( HAPE) .Methods Based on the Lake Louise Self-assessmeat Scoring System ( LLSS) and the scoring of respiratory symptoms, 628 subjects were divided into three groups: group A ( the healthy;score<3),group B(acute mountain sickness, AMS; score>3 and excluding HAPE),and group C (HAPE).Moreover, we analyzed the incidence of some clinical symptoms, HR and SaO2 , as well as the WBC number of some subjects in the three groups.Results The incidence of respiratory symptoms and WBC number were significantly increased in group C compared with group B(P<0.05).In addition,unlike group A and B, the mean HR in group C rose gradually in the first 3 days and was markedly increased at the third day(F=6.37,P<0.05).The mean SaO2in group C was remarkably lower than in group A and B in the first 3 days(F=8.21,F=8.77,F=9.58,P<0.01).Conclusion Those who enter high altitude for the first time with notable respiratory symptoms, WBC increase, HR maladaptation and decrease in SaO2 (>30%) have high risk of HAPE.It is of special importance to detect HAPE earlier at high altitude.