胰岛素对大鼠血管平滑肌细胞增殖和凋亡的影响

Effects of insulin on proliferation and apoptosis of rat vascular smooth muscle cells

目的 探讨胰岛素对血管平滑肌细胞增殖和凋亡的影响 .方法 体外进行大鼠血管平滑肌细胞的培养 ,以 5～ 10代细胞为实验对象 ,随机分成空白对照组和胰岛素组 ,胰岛素组又按浓度 1× 10 - 9、1× 10 - 8、1× 10 - 7和 1× 10 - 6 mol· L- 1分为 4小组 ,在加药后 2 4 h、4 8h和 72 h用 MTT法分析细胞增殖活力 ,免疫细胞化学观察细胞核增殖抗原 (PCNA)的表达 ,用末端脱氧核苷酸转移酶介导的 d UTP缺口末端标记法检测 H2 O2 诱导的细胞凋亡 .结果 加药 4 8h后 ,1× 10 - 9mol· L- 1胰岛素组的 MMT A值 (0 .4 2± 0 .0 4 )高于空白组(0 .30± 0 .0 2 ) ,P<0 .0 5 ,低于 1× 10 - 6 mol· L- 1 胰岛素组(0 .5 2± 0 .0 5 ) ,P<0 .0 5 ;1× 10 - 9mol·L- 1胰岛素作用 4 8h后细胞的 MMT A值比空白组增加 4 0 % ,高于 2 4 h细胞的MMT A值增加率 (2 7% ) ,P<0 . 0 5 ;1× 10 - 9～ 1× 10 - 6mol· L- 1 胰岛素作用 4 8h后细胞 PCNA的表达率 (5 0 %～80 % )均高于空白对照组的 (30 % ) P<0 .0 5 ;加药 2 4 h后 ,1× 10 - 6 mol· L- 1胰岛素组细胞凋亡率 (30 % )低于空白组(70 % ) P<0 .0 5 .结论 胰岛素有明显促 VSMC(vascularsmooth m uscle cells)增殖的作用 ,并且这种作用时间和浓度依赖性 ;

AIM To study the effects of insulin on the proliferation and apoptosis of rat vascular smooth muscle cells. METHODS The cells of 5~10 passages of cultured VSMC were used in the experiment and were divided into control group and insulin group. Insulin group was sabdivided into four groups by 1×10 -9 , 1×10 -8 , 1×10 -7 and 1×10 -6 mol·L -1 concentration. MTT assay, terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) and immunocytochemistry were used respectively to detect the VSMC proliferation, apoptosis and expression of proliferating cell nuclear antigene (PCNA) at 24 h, 48 h and 72 h. RESULTS The value of MTT absorbance of 1×10 -9 mol·L -1 group (0.42±0.04) was higher than that of the control group (0.30±0.02), but lower than that of 1×10 -6 mol·L -1 group (0.52±0.05), P <0.05. The increased percentage of MTT absorbance of 1×10 -9 mol·L -1 group at 48 h (40%) was higher than that of 1×10 -9 mol·L -1 group at 24 h (27%), P <0.05. The percentage of PCNA expression of VSMCs with 1×10 -9 ~1×10 -6 mol·L -1 insulin (50~80%) at 48 h was higher than that of the control group. The percentage of apoptotic cells of 1×10 -6 mol·L -1 insulin group (30%) decreased compared with the control group (30%). CONCLUSION Insulin can stimulate the proliferation of VSMC in a time and dose dependent manner. Insulin can inhibit the apoptosis of VSMCs.