4-氨基吡啶对豚鼠心室肌钙和钠电流的影响

目的研究4-氨基吡啶(4-AP)对心肌细胞L型钙通道和钠通道的影响。方法用全细胞膜片钳技术考察4-AP对豚鼠心室肌细胞L型钙电流和钠电流的作用。结果4-AP0.1,0.5,1.0mmol·L^-1浓度依赖性地抑制L型钙电流(I_Ca，L)和钠电流(I_Na),抑制率分别为(11.6±1.7)%，(37.5±8.3)%和(54.5±6.9)%以及(22.1±14.3)%，(39.4±8.8)%和(62.3±6.8)%。0.5mmol·L^-14-AP使I_Ca，L和I_NaI-V曲线均上移。结论4-AP可浓度依赖性地阻滞豚鼠心室肌细胞L型钙通道和钠通道。

EFFECTS OF 4-AMINOPYRIDINE ON CALCIUM CURRENTS AND SODIUM CURRENTS IN GUINEA PIG VENTRICULAR MYOCYTES

AIM: To investigate the effect of 4-aminopyridine (4-AP) on ion channels of myocytes. METHODS: L-type calcium channel and sodium channel currents were recorded in guinea pig single ventricular myocyte using whole-cell patch-clamp techniques. RESULTS: 4-AP, 0.1, 0.5 and 1.0 mmol.L-1 were shown to inhibit L-type calcium channel currents (ICa, L) and sodium channel currents (INa) concentration-dependently. The percentage of inhibition were (11.6 +/- 1.7)%, (37.5 +/- 8.3)% and (54.5 +/- 6.9)% (P < 0.01) respectively for ICa, L, and (22.1 +/- 14.3)% (P < 0.05), (39.4 +/- 8.8)% and (62.3 +/- 6.8)% (P < 0.01) respectively for INa. 4-AP 0.5 mmol.L-1 shifted the I-V curves of ICa, L and INa upwardly. CONCLUSION: 4-AP blocked L-type calcium channel and sodium channels in guinea-pig ventricular myocytes concentration-dependently.