酮替芬对新生大鼠心肌细胞内游离钙的影响

Effect of ketotifen on the free calcium in neonatal rat myocardial cells

观察了酮替芬 (Ket)对新生鼠心肌细胞内游离钙的影响 ,以酶法制备新生大鼠心肌细胞悬液 ,用荧光探针Fura - 2 /AM检测心肌细胞内游离钙浓度的变化。结果表明 :Ket对静息状态下 [Ca2 +]i无影响 ,Ket(10～ 5 0 0 μmol/L)剂量依赖性抑制高钾去极化及NE所致的 [Ca2 +]i 升高。提示 :Ket对心肌细胞膜上电压依赖性钙通道有抑制作用 。

The effect of ketotifen (Ket) on intracellular free calcium concentration([Ca^(2+) ] i) was examined in freshly isolated myocardial cells prepared from neonatal rats using the [Ca 2+ ] i-sensitive fluorescence indicator Fura-2/AM. Ket had no effect on resting [Ca 2+ ] i whereas Ket(10～500 μmol/L) concentration-dependently inhibited[Ca 2+ ] i elevation induced by high extracellular potassium and NE. These results suggest that Ket inhibits [Ca 2+ ] i influx through voltage-dependent calcium channels and maybe through receptor-operated calcium channels in myocardial cells.