胰岛素对心脏细胞增殖的影响及其在心肌肥厚中的作用

目的　研究胰岛素对心肌细胞和心肌成纤维细胞增殖的影响 ,探讨其在心肌肥厚中的作用。方法　①乳鼠心肌细胞和心肌成纤维细胞的培养及光镜、电镜和免疫细胞化学染色的鉴定。②两种细胞在不同浓度胰岛素作用下细胞数量、代谢活性与DNA合成 (WST 1、BrdUELISA法 )的测定及细胞周期分析 (流式细胞仪 )。结果　①培养的心脏细胞分别为心肌细胞和成纤维细胞。②胰岛素作用下 ,心肌细胞的数量、WST 1与BrdU的OD值及S +G2 +M期细胞百分比无变化 (P >0 0 5 ) ;而心肌成纤维细胞的数量、WST 1与BrdU的OD值及S +G2 +M期细胞百分比均升高 (P <0 0 1或P <0 0 5 )。结论　胰岛素可促进培养的心肌成纤维细胞增殖 ,可能在心肌肥厚中起重要作用

Effects of insulin on proliferation of heart cells and its role in induction of cardiac hypertrophy

AIM To study the effects of insulin on proliferation of cardiac myocytes and cardiac fibroblasts and its role in induction of cardiac hypertrophy. METHODS ① The neonatal rat cardiac myocytes and cardiac fibroblasts were cultured and identified with light , electron microscopy and immunocytochemistry respectively. ②After the cells were treated with different concentration of insulin, cell proliferation were measured with cell counting , WST 1 metabolic activity and BrdU enzyme linked immunosorbent assay (ELISA) and cell cycle analysis by flow cytometry. RESULTS ① The cultured heart cells showed the morphology and immunocytochemistry characteristic of myocytes and fibroblasts respectively. ② Cell number, optical density of WST 1 cleavage products,BrdU incorporation and the percentage of S+G 2+M of cardiac fibroblasts increased significantly in the presence of insulin ( P <0 01 or P< 0 05). However, the above parameters of cardiac myocytes were not different between insulin treated group and blank control group ( P> 0 05). CONCLUSION Insulin can promote proliferation of the cultured cardiac fibroblasts. Therefore it may play an important role in induction of cardiac hypertrophy.