银杏叶提取物对D-半乳糖诱导心肌细胞老化的肌浆网钙摄取及SERCA活性的影响

Effects of extract of ginkgo biloba on calcium uptake capacity and activity of SERCA in sarcoplasmic reticulum of cardiomyocyte ageing induced by D-galactose

目的探讨银杏叶提取物EGB761对D-半乳糖诱导的心肌细胞老化肌浆网钙摄取能力及肌浆网Ca2+-ATP酶(SERCA)活性的影响。方法实验分正常对照组(C组)、D-半乳糖组(5 g/L)(A组)、D-半乳糖+EGB761组(B组)。用荧光钙离子指示剂Fura-2/AM,激光共聚焦显微镜(LSCM)测定心肌细胞肌浆网钙摄取能力及改良的p-NPP法测定SERCA活性。结果与C组相比,A组心肌细胞舒张期钙离子浓度明显升高(0.71±0.08 vs.0.59±0.06)(P<0.05);舒张期钙离子回摄时间明显延长[(1000.95±129.34)ms vs.(775.15±121.68)ms](P<0.05);咖啡因刺激后,钙离子增幅明显减少(0.11±0.02 vs.0.53±0.19)(P<0.05),细胞内SERCA活性明显降低。与A组相比,B组舒张期钙离子浓度明显降低,舒张期钙离子回摄时间明显缩短;咖啡因刺激后,钙离子瞬变增幅明显增高,细胞内SERCA活性明显提高。结论银杏叶提取物EGB761对D-半乳糖诱导老化的心肌细胞肌浆网钙摄取功能和SERCA活性有一定程度的提高。

Objective To study the effects of extract of ginkgo biloba on calcium uptake capacity and activity of sarcoplasmic reticutum Ca2＋-ATPase （SERCA） in sarcoplasmic reticulum of cardiomyocyte ageing induced by D-galactose. Methods The D-galactose-induced ageing cardiomyocytes were divided into three groups of C （control）, A（treated with D-galactose） and B （treated with D-galactose and the extract of ginkgo biloba, EGB761）. The calcium uptake capacity and activity of SERCA in sarcoplasmic reticulum of cardiomyocyte ageing were examined by fluorescent calcium indicator Fura-2/AM and laser scanning confocal microscopy（LSCM）. Results Compared to group C, the diastolic calcium concentration was higher in group A than that in group C （0.71±0. 08 vs. 0.59±0.06） （P〈0.05） ,hut the time from the maximum concentration of calcium to baseline was prolonged[（1000. 95±129.34） ms vs. （775.15±121.68） ms]（P〈0.05）. After treated with caffeine, the amplitude of calcium transient was increased （0. 11±0.02 vs. 0.53±0.19）（P〈0. 05）, but the activity of SERCA in the cells was reduced in group A. Compared to group A, the diastolic calcium concentration was lower, but the time from the maximum concentration of calcium to baseline was shorter, in group B. After treated with caffeine, the amplitude of calcium transient was reduced, but the activity of SERCA in the cells was increased in group B. Conclusion Extract of ginkgo biloba EGB761 on The capacity of calcium uptake and activity of SERCA in sarcoplasmic reticulum of D-galactoseinduced aging of cardiac myocytes are enhanced to a certain extent.