冬虫夏草对豚鼠心室肌细胞胞浆钙离子浓度及L-型钙电流的影响

目的　研究冬虫夏草 (Codycepssinensis,CS)水提液对豚鼠单个心室肌细胞胞浆内钙离子浓度 (Ca2 ]i)及L 型钙电流 (ICa L)的影响。方法　酶解法分离豚鼠单个心室肌细胞 ,应用激光扫描共聚焦显微镜联合全细胞膜片钳技术测定豚鼠心室肌细胞 Ca2 ]i以及ICa L的变化。结果　应用 0 1mg/mL (生药浓度 )冬虫夏草水提液 ,在静息状态下对 Ca2 ]i 无影响 ;对 6 0mmol/LKCl诱导的胞浆 Ca2 ]i升高有促进作用 ,峰值荧光强度在 12 0s时由12 0 4 3± 2 38 4增加至 185 5 2± 32 1 0 (n =6 ,P <0 0 5 )。膜片钳研究结果表明 ,冬虫夏草水提液可明显促进ICa L,使ICa L从 (- 15 1± 2 3)pA/ pF增加到 (- 19 7± 3 2 ) pA/pF (刺激电压为 10mV ,n =8,P <0 0 1)。 结论　冬虫夏草水提液促进心肌细胞钙内流 ,是该药治疗缓慢型心律失常的机制之一。

Effects of Cordyceps sinensis on intracellular calcium concentration and L-type calcium current of ventricular mytocytes in guinea pig

Object To study the effects of Cordyceps sinensis (Berk.) Sacc. (CS) on intracellular calcium concentration (Ca²⁺]_i) and L-type calcium current (I Ca-L) of the single cell from ventricular myocytes in guinea pig. Methods Zymolytic method was used to isolate single cell of ventricular myocytes in adult guinea pig, which were loaded with Ca ²⁺]_isensitive fluorescent indicator Fluo-3/AM. Ca²⁺]_i represented by fluorescent intensity (FI) was measured by laser scanning confocal microscope. Whole cell patch clamp technique was used to record I Ca-L. Results At resting state, CS (0.1 mg/mL) did not affect Ca²⁺]_i compared with the control. CS (0.1 mg/mL) enhanced the increase of Ca²⁺]_i induced by KCl 60 mmol/L. The peak value of fluorescent intensity was increased from 1 204.3±238.4 to 1 855.1±321.0 (n=6, P0.05); I Ca-L was increased by CS (0.1 mg/mL) from (-15.1±2.3) pA/pF to (-19.7± 3.2) pA/pF, corresponding to a percent increase of 30.07% (n=8, P0.05) in guinea pig ventricular myocytes for the treatment of bradyrhythmia. Conclusion Elevation of intracellular calcium concentration by CS may contribute to its positively inotropic effects for the treatment of bradyrhythmia.