【摘要】 目的:研究蜂毒肽（Melittin,Mel）对豚鼠心室肌细胞钾电流和动作电位的影响.方法:全细胞膜片箝记录.结果:蜂毒肽可呈浓度依赖性促进延迟整流钾电流（I_k）,在测定电压为40 mv时,0.05,0.1,0.2μmol·L^-1蜂毒肽分别使I_k从（295±109）增大到（371±142）（n=5 P<0.05）,（467±180）（n=5,P<0.05）,（552±248）pA（n=5,P<0.05）.但药物在三个浓度时对内向整流钾电流(I_k1)均无显著影响.蜂毒肽0.05,0.1,0.2 μmol·L^-1分别使动作电位APD₅₀由（520±55）减小到（459±91）（n=5,P>0.05）,（385±102）（n=5,P<0.01）,（281±81）ms（n=5,P<0.01）,使APD₉₀由（613±96）减小到（536±93）（n=5,P>0.05）,（467±96）（n=5,P<0.01）,（354±95）ms（n=5,P<0.01）.结论:蜂毒肽促进延迟整流钾电流,缩短动作电位时程.更多还原

【Abstract】 AIM: To examine the effects of melittin (Mel) , the major component of bee venom, on delayed rectifier K+ current (Ik), inward rectifier K+ current (Ik1) and ac-tion potential (AP) in guinea pig ventricular myocytes. METHODS: Ik, Ik1, and AP were recorded using the whole-cell patch-clamp technique. RESULTS: The ac-tion potential duration (APD) was shortened by Mel in a concentration-dependent manner. Mel 0.05, 0.1, 0.2 μmol·L-1 shortened APD50 from (520 ±55) to (459± 91) (n =5, P >0.05), (385± 102) (n =5, P < 0.01), and (281±81) ms (n=5, P<0.01), respec-tively; and APD90 from (613± 96) to (536±93) ( n = 5, P>0.05), (467±96) ms (n=5, P<0.01), and (354±95) ms (n = 5, P < 0.01), respectively. Mel increased the amplitude of Ik also in a concentration-de-pendent manner. Mel 0.05, 0.1, 0.2 μmol·L-1 in-creased Ik from (295 ±109) to (371 ± 142) (n = 5, P <0.05), (467±180) (n = 5, P<0.05), (552±248) pA (n = 5, P < 0.05), respectively at testing potential of + 40 mV. But no significant effect of Mel on Ik1 was observed at these concentrations. CONCLUSION: Mel significantly increased Ik in a concentration-dependent manner which contributed to shortening of APD.更多还原