Guan Qi-gang, Zeng Ding-yin, Sun Xi-zhuo, Miao Zhi-Lin, Zhou Xu-chen, He Xue-zhi, Han Feng-tong, Cheng Ying, Zhang Li
Department of Cardiology, First Affiliated Hospital of China Medical University, Shenyang 110001, China.
Zhonghua Xin Xue Guan Bing Za Zhi. 2006 Jan;34(1):50-3.
Phosphorylation of myosin light chain (MLC) is one of the most important steps for vascular smooth muscle contraction and Rho-kinase is involved in this process. We investigated the role of Rho-kinase in a porcine coronary artery spasm model with interleukin-1beta.
Segments of left coronary artery adventitia were surrounded by normal saline (n = 8) or IL-1beta agarose microne (n = 8) for 2 weeks. Vasospastic responses to intracoronary serotonin or histamine then studied at the saline or IL-1beta-treated site. The Rho-kinase mRNA expression in the treated site was measured by reverse transcription-polymerase chain reaction analysis (RT-PCR). The extent of phosphorylation of myosin-binding subunit of myosin phosphates (MBS, one of the major substrates of Rho-kinase) were quantified by Western blot analysis.
Intracoronary serotonin or histamine repeatedly induced coronary artery spasm and coronary arterial stenosis was evidenced at IL-1beta-treated site. Expression of Rho-kinase mRNA in IL-1beta-treated site was significantly increased compared to saline treated site (98.20% +/- 7.66% vs. 63.70% +/- 4.26%, P < 0.05). Western blot analysis showed that during the serotonin-induced contractions the extent of phosphorylation of MBS was also significantly increased in the spastic site (25,485 +/- 4745 vs. 6510 +/- 779, P < 0.05).
Rho-kinase upregulation at the spastic site and increased phosphorylation of myosin-binding subunit of myosin phosphates are key players in inducing vascular smooth muscle hypercontraction in this porcine model.
肌球蛋白轻链（MLC）磷酸化是血管平滑肌收缩的最重要步骤之一，Rho激酶参与这一过程。我们研究了Rho激酶在白细胞介素-1β诱导的猪冠状动脉痉挛模型中的作用。
将左冠状动脉外膜段分别用生理盐水（n = 8）或白细胞介素-1β琼脂糖微珠（n = 8）包绕2周。然后在生理盐水或白细胞介素-1β处理部位研究对冠状动脉内5-羟色胺或组胺的血管痉挛反应。通过逆转录-聚合酶链反应分析（RT-PCR）测量处理部位Rho激酶mRNA的表达。通过蛋白质印迹分析定量肌球蛋白磷酸酶的肌球蛋白结合亚基（MBS，Rho激酶的主要底物之一）的磷酸化程度。
冠状动脉内5-羟色胺或组胺反复诱发冠状动脉痉挛，白细胞介素-1β处理部位出现冠状动脉狭窄。与生理盐水处理部位相比，白细胞介素-1β处理部位Rho激酶mRNA的表达显著增加（98.20%±7.66%对63.70%±4.26%，P < 0.05）。蛋白质印迹分析显示，在5-羟色胺诱导的收缩过程中，痉挛部位MBS的磷酸化程度也显著增加（25485±4745对6510±779，P < 0.05）。
在该猪模型中，痉挛部位Rho激酶上调以及肌球蛋白磷酸酶的肌球蛋白结合亚基磷酸化增加是诱导血管平滑肌过度收缩的关键因素。
