拉西地平对CTGF诱导大鼠心肌细胞肥大的影响及其与ERK1/2的关系

目的 观察拉西地平对结缔组织生长因子（CTGF）诱导大鼠心肌细胞肥大的作用，探讨其作用与细胞外信号调节激酶1/2（ERK1/2）的关系。方法 以培养的新生SD大鼠的心肌细胞为实验模型，用图象分析法、3H-亮氨酸掺入法、考马斯亮蓝染色、蛋白免疫印迹法（Western blot）等，评价拉西地平对CTGF诱导心肌细胞肥大的抑制作用及其与ERK1/2的关系。结果 ①以50 ng/L的CTGF作用24 h后，心肌细胞表面积为（1 812.52±168.73）μm2，与对照组（689.31±96.58）μm2比较显著增加（P<0.01）；5、10、25及50 μmol/L拉西地平干预组的心肌细胞表面积分别为（1 476.52±156.73）μm2、（1 120.39±149.68）μm2、（926.10±101.44）μm2及（739.81±91.55）μm2，与CTGF组比较呈浓度依赖性降低（P<0.01）。②以50 ng/L的CTGF作用24 h后，心肌细胞的3H-亮氨酸掺入率为（2 368.72±122.45）cpm/孔，与对照组（950.26±89.43）cpm/孔比较显著增加（P<0.01）。 5、10、25及50 μmol/L拉西地平干预组的心肌细胞的3H-亮氨酸掺入率，分别为（2023.12±106.15）cpm/孔、（1629.15±103.46）cpm/孔、（1302.19±98.53）cpm/孔及（1 055.72±90.96）cpm/孔，与CTGF组比较呈浓度依赖性降低（P<0.01）。③以50 ng/L的CTGF作用24 h后，心肌细胞蛋白的含量为（1.692±0.203）ng/细胞,与对照组（0.622±0.068）ng/细胞比较显著增加（P<0.01）;5、10、25及50 μmol/L拉西地平干预组的心肌细胞蛋白的含量分别为（1.269±0.167）ng/细胞、（0.923±0.119）ng/细胞、（0.766±0.085）ng/细胞及（0.682±0.063）ng/细胞，与CTGF组比较呈浓度依赖性降低（P<0.01）。④50 ng/L CTGF组的心肌细胞p-ERK1/2表达强度明显高于对照组，5 μmol/L、10 μmol/L、25 μmol/L、50 μmol/L拉西地平干预组心肌细胞p-ERK1/2的表达强度与CTGF组比较呈浓度依赖性降低。心肌细胞t-ERK1/2的表达在各组之间没有明显的差异。结论 拉西地平可抑制CTGF诱导的心肌细胞肥大，其作用机制可能与ERK1/2磷酸化有关。

Effect of lacidipine on cardiac myocyte hypertrophy induced by CTGF and its relationship with ERK1/2

AIM To study the effect of lacidipine on cardiac myocytes hypertrophy induced by connective tissue growth factor(CTGF) and its relationship with ERK1/2. METHODS Neonatal cardiomyocytes were obtained from Sprague-Dawley (SD) rats. Image analysis system, 3H-leucine incorporation technique, Coomassie Brilliant blue staining and Western-blot were used to investigate the inhibitory effect of lacidipine on cardiac myocytes hypertrophy induced by CTGF and its relationship with ERK1/2. RESULTS ①50ng/L CTGF significantly increased cardiomyocyte surface area ［(1812.52±168.73)μm2］ in comparison with that in control group ［(689.31±96.58)μm2, P<0.01)］. Lacidipine in the range of 5-50 μmol/L (5, 10, 25 and 50 μmol/L respectively) attenuated the cardiomyocyte surface area in a concentration dependent manner ［(1 476.52±156.73), （1 120.39±149.68）, （926.10±101.44） and （739.81±91.55）μm2, P<0.01］. ②Compared with that in control group ［(950.26±89.43)cpm/well)］, the 3H-leucine incorporation rate was markedly increased by 50 ng/L CTGF ［(2 368.72±122.45)cpm/well, P<0.01］. Lacidipine in the range of 5-50 μmol/L attenuated the 3H-leucine incorporation rate in a concentration dependent manner［(2 023.12±106.15), （1 629.15±103.46）, （1302.19±98.53） and （1055.72±90.96）cpm/well, P<0.01］. ③The cardiomyocyte protein content in 50 ng/L CTGF group ［(1.692±0.203)ng/cell］ was significantly higher than that in control group ［(0.622±0.068)ng/cell, P<0.01］. Lacidipine in the range of 5-50 μmol/L attenuated the cardiomyocyte protein content in a concentration dependent manner ［(1.269±0.167, 0.923±0.119), （0.766±0.085） and （0.682±0.063）ng/cell, P<0.01］. ④The protein level of p-ERK1/2 was markedly increased by 50 ng/L CTGF than that in control group. Lacidipine in the range of 5-50 μmol/L attenuated the protein level of p-ERK1/2 in a concentration dependent manner compared with that of the control group. But thers is no significant distinction among the different lacidipine intervention groups. CONCLUSION Lacidipine can inhibit cardiac myocytes hypertrophy induced by CTGF and the mechanism of this effect may be related to the phosphorylation of ERK1/2.