新生鼠心室成纤维细胞条件培养液增加心肌细胞搏动频率的作用

THE EFFECT OF CONDITIONED GROWTH MEDIUM OF VENTRICULAR FIBROBLASTS INCREASE BEATING RATE ON CULTURED NEONATAL RATS CARDIOMYOCYTES

目的和方法 :利用细胞培养和RT PCR技术研究新生大鼠心脏成纤维细胞增加心肌细胞搏动频率的作用。结果 :成纤维细胞条件培养液在 48h内能明显增加心肌细胞的搏动频率 ,并具有时间依赖性和剂量依赖性 ,内皮素 1(ET 1)ETA 受体拮抗剂BQ12 3 能部分阻断成纤维细胞条件培养液增加心肌细胞搏动频率作用 ,而血管紧张素ⅡATl 受体拮抗剂CV 11974和α 肾上腺素受体拮抗剂Regitin却无此效果 :RT PCR的结果显示心室成纤维细胞、心肌细胞和皮肤成纤维细胞均有 ppET 1mRNA的表达 ,心室成纤维细胞中表达的丰度大于心肌细胞和皮肤成纤维细胞。百日咳毒素 (PTX)也能部分阻断成纤维细胞条件培养液增加心肌细胞搏动频率的作用。结论 :心室成纤维细胞能分泌ET 1等生物活性物质 ,对心肌细胞具有正性变时作用 ,同时提示分泌ET 1的功能并非心室成纤维细胞所特有 。

Aim and Methods:To study the effect of ventricular fibroblasts increase beating rate on cultured neonatal rat cardiomyocytes by using cell culture and RTPCR technique. Results: We found that conditioned growth medium (FCGM) of cultured neonatal rat ventricular fibroblast within 48 h could significantly increase beating rate of neonatal rat cardiomyocyte, the response was the timedependent and dosedependent; BQ 123 , an ET A receptor antagonist, partly blocked the effect, but CV11974, Ang Ⅱ Itype receptor antagonist and Regitin, αadrenergic receptor antagonist did not. The results of RTPCR indicated that there was the expression of ppET1 mRNA in venticular fibroblasts, cardiac myocytes and skin fibroblasts, but the abundance of ppET1 mRNA was the highest in the ventricular fibroblasts. The FCGMinduced increase in cardiomyocyte beating rate was inhibited partly by pertuses toxin (PTX).Conclusion: There were substances in FCGM on positive chromotropic actions of cardiomyocytes,which were ET1 and others. The groups of fibroblasts could secreted ET1, and this was not the specify of ventricular fiblroblast. The effect of FCGM increase beating rate on cultured cardiomyocytes was related with PTX sensitive G protein.