观察乙酰胆碱 (ACh)诱发的豚鼠心室肌肌力及钙电流的反跳作用 ,并探讨其作用机制。采用豚鼠离体左室乳头肌观察 1μmol/LACh单独对心室肌收缩力 (Fc)的影响及在 10nmol/L异丙肾上腺素 (Iso)存在时对Fc的影响 ,并应用膜片钳全细胞记录方法分别观察 1μmol/LACh和 1μmol/LACh +10nmol/LIso及迅速洗脱ACh对豚鼠心室肌细胞L型钙通道电流 (ICa L)的影响。结果 :1μmol/LACh对心室肌Fc有直接抑制作用 ,抑制率为 30 .8%± 10 .7%(P <0 .0 5 ) ,而快速洗脱ACh后 ,Fc反跳性增强了 2 5 .5 %± 10 .3% (n =7,P <0 .0 1)。而在应用 10nmol/LIso后 1μmol/LACh对Fc有间接的抑制作用 ,快速冲洗ACh后亦引起Fc的反跳性增强 ,与Iso组相比增强了 2 7.1%±13.2 % (n =7,P <0 .0 1)。 1μmol/LACh对心室肌细胞基础峰电流无明显影响 (n =8,P >0 .0 5 ) ;而以基础ICa L峰值(931± 16 1pA)作对照 ,在加入 10nmol/LIso后 ,ICa L峰电流增强到 1889± 331pA(n =7,P <0 .0 1) ;再给予 10nmol/LIso +1μmol/LACh快速灌流 2min ,峰电流降低为 15 12± 2 0 2pA(P <0 .0 1) ,用含 10nmol/LIso的细胞外液快速洗脱ACh ,峰电流增强到 2 10 7± 2 0 5pA ,较Iso组反跳性增强了 15 .8%± 4 .0 % (n =7,P <0 .0 1)。结论 :ACh对豚鼠心室肌收缩 To observe the rebound effect of acetylcholine (ACh) -induced ventricular cardiac muscle strength and calcium current in guinea pigs and to explore its mechanism. The left ventricular papillary muscle of guinea pigs was used to observe the effects of 1μmol / LACh alone on the contractile force (Fc) of ventricular muscles and the effect of Fc on the Fc in the presence of 10nmol / L isoproterenol (Iso) Methods The effects of 1μmol / LACh, 1μmol / LACh + 10nmol / LIso ​​and rapid elution of ACh on L-type calcium channel current (ICa L) of guinea pig ventricular myocytes were observed. Results: 1 μmol / LACh had a direct inhibitory effect on Fc of ventricular myocardium with an inhibitory rate of 30.8% ± 10.7% (P <0.05), while Fc was rapidly reversed after ACh was accelerated .5% ± 10 .3% (n = 7, P <0.01). However, 1μmol / LACh had an indirect inhibitory effect on Fc at 10nmol / L O after administration of ACh, and the fast rebound of Fc was also enhanced after ACh treatment, which increased by 21.1% ± 13.2% compared with Iso group (n = 7, P <0 .0 1). 1μmol / LACh had no significant effect on the basal peak current of ventricular myocytes (n = 8, P> 0.05); while the ICa L peak (931 ± 161pA) The peak current was increased to 1889 ± 331pA (n = 7, P <0.01), and then rapidly perfused with 10nmol / LIso ​​+ 1μmol / LACh for 2min, the peak current decreased to 1512 ± 202pA ), The ACh was rapidly eluted with extracellular solution containing 10nmol / L Lso, the peak current increased to 2 10 7 ± 20 05pA, which was 15.8% ± 4. 0% (n = 7, P <0 .0 1). Conclusion: ACh contracted guinea pig ventricular muscle