冷应激对大鼠血管平滑肌细胞钙通道表达的影响

目的 观察冷应激对大鼠血管平滑肌细胞钙通道α1C亚基表达的影响.方法 建立冷应激高血压模型.每2周测量大鼠的血压.24只健康成年SD大鼠随机分为对照组(6只)和寒冷暴露组(18只),寒冷暴露组大鼠分别于暴露的第2、4、6周处死,应用半定量反转录-聚合酶链反应(RTPCR)检测主动脉钙离子通道α1C亚基的表达.结果 寒冷暴露组大鼠血压从第2周开始升高,2周时冷应激大鼠模型血压为(102.8±2.25)mm Hg,对照组大鼠血压为(89.2±3.73)mm Hg,差异有统计学意义(P＜0.05);4、6周时冷应激大鼠模型血压分别为(114.5±4.21)、(121.9±3.03)mm Hg,与对照组比,差异有统计学意义(P＜0.01).寒冷暴露组血管平滑肌钙离子通道α1C亚基mRNA水平升高,2、4、6周冷应激大鼠模型钙离子通道α1C亚基mRNA分别为0.21±0.02、0.33±0.05、0.57±0.08,与对照组(0.13±0.02)比,差异有统计学意义(P＜0.01).钙通道α1C亚基mRNA的相对表达量与血压呈高度相关(r=0.86,P＜0.01).结论 反复寒冷暴露能诱发冷应激性高血压,导致血管平滑肌细胞上钙通道α1C亚基表达水平升高.

Abstract：

Objective To observe the expression of vascular smooth muscle cells calcium channel α1C subunit (LTCCα1C) in rats exposed in low temperature. Methods Cold-induced hypertension was established and blood pressure was measured every two weeks. The mRNA expression of L type calcium channel α1C was determined by RT-PCR. Results The blood pressure of the rats exposed to cold environment increased. The blood pressure of experimental groups [( 102.8±2.25)mm Hg] began to increase from the first two weeks, compared with the control group[(89.2±3.73 )mm Hg], there were significant difference (P＜0.05). The blood pressure of experimental groups were ( 114.5 ±4.21 ), ( 121.9±3.03 ) mm Hg respectively at 4, 6 weeks. Compared with the control group, the expression of LTCCα1C mRNA of the cold exposure group increased significantly (P＜0.01). There was a significant correlation between the expression of LTCCα1C mRNA and the blood pressure of the rats (r=0.86,P＜0.01 ). Conclusion Repeated cold exposure can establish cold-induced hypertension, and the level of vascular smooth muscle cells LTCCα1C expression increase.

Effect on expression of vascular smooth muscle cell calcium channel in rats exposed in low temperature

Objective To observe the expression of vascular smooth muscle cells calcium channel α1C subunit (LTCCα1C) in rats exposed in low temperature. Methods Cold-induced hypertension was established and blood pressure was measured every two weeks. The mRNA expression of L type calcium channel α1C was determined by RT-PCR. Results The blood pressure of the rats exposed to cold environment increased. The blood pressure of experimental groups [( 102.8±2.25)mm Hg] began to increase from the first two weeks, compared with the control group[(89.2±3.73 )mm Hg], there were significant difference (P＜0.05). The blood pressure of experimental groups were ( 114.5 ±4.21 ), ( 121.9±3.03 ) mm Hg respectively at 4, 6 weeks. Compared with the control group, the expression of LTCCα1C mRNA of the cold exposure group increased significantly (P＜0.01). There was a significant correlation between the expression of LTCCα1C mRNA and the blood pressure of the rats (r=0.86,P＜0.01 ). Conclusion Repeated cold exposure can establish cold-induced hypertension, and the level of vascular smooth muscle cells LTCCα1C expression increase.