中国病理生理杂志2012，Vol.28Issue(4)：589-594,6.DOI:10.3969/j.issn.1000-4718.2012.04.003
肌球蛋白轻链激酶在失血性休克大鼠离体淋巴管收缩性双相变化中的作用
Role of myosin-light-chain kinase in biphasic contractile activity of lymphatics isolated from hemorrhagic shock rats
摘要
Abstract
AIM: To elucidate the mechanism by which myosin -light -chain kinase (MLCK) modulates the biphasic contractile activity of lymphatics isolated from the rats subject to hemorrhagic shock ( HS). METHODS: Male Wistar rats were randomiz to control group and HS group . In HS group, the rats were subject to HS and then further divided into HS 0 h, 0. 5 h, 1 h, 2 h and 3 h subgroups. Thoracic ducts of control and shock rats were isolated and used to deter -mine the protein levels of phosphorylated MLCK (p - MLCK). In addition, thoracic ducts obtained from control , 0. 5 h - and 2 h - shocked rats were used to observe the contractile properties of lymphatics by a pressure myograph in vitro. Lymphatic rings were prepared and incubated with ML - 7 (a specific inhibitor of MLCK) or substance P (SP, an agonist of MLCK). During the experiment, the contractile frequency (CF) , end - diastolic diameter, end - systolic diameter and passive diameter in Ca - free PSS buffer were measured and used to calculate the lymphatic tonic index (TI) , contractile amplitude ( CA) and fractional pump flow (FPF) as the indexes of lymphatic contraction activity . RESULTS: The levels of p - MLCK in lymphatics in 0 h - and 0. 5 h - shocked rats were significantly increased compared with the control rats , and it was gradually decreased with the development of shock . The values of CF , TI and FPF in 0. 5 h - shocked lymphatics were significantly increased at transmural pressure of 1 , 3 and 5 cmH2 0 compared with those in control group , and significantly blunted by ML -7. SP obviously increased the suppressive effects induced by ML -7 and restored the values ofCF, TI and FPF to the levels of HS 0. 5 h group. CF, TI and FPF in 2 h - shocked lymphatics significantly declined under different transmural pressure as compared with those in control group , and significantly elevated by SP. Similarly, ML - 7 depressed the effects of SP. No significant difference was found in CA between 0. 5 h - and 2 h - shocked lymphatics. SP decreased the CA of lymphatics obtained from 2 h - shocked rats and this effect was suppressed by ML -7. However, both agents had no effects on CA of 0. 5 h - shocked lymphatics. CONCLUSION; MLCK, as an essential enzyme that influences the contraction of lymphatic smooth muscle cells , involves in the modulation of biphasic changes of lymphatic contrac -tile activity during the process of HS.关键词
休克/出血性/淋巴管/收缩性/肌球蛋白轻链激酶Key words
Shock , hemorrhagic/Lymphatics/Contractility/Myosin-light-chain kinase分类
医药卫生引用本文复制引用
张玉平,牛春雨,赵自刚,秦立鹏,司永华,张立民,张静..肌球蛋白轻链激酶在失血性休克大鼠离体淋巴管收缩性双相变化中的作用[J].中国病理生理杂志,2012,28(4):589-594,6.基金项目
国家自然科学基金资助项目(No.30770845) （No.30770845）
河北省自然科学基金资助项目(No.C2008000503) （No.C2008000503）
河北省教育厅科学研究重点项目(No.ZH2007101) （No.ZH2007101）
河北省百名优秀人才支持计划(No.CPRC047) （No.CPRC047）
