Objective:To examine the role of p38 mitogen-activated protein kinase (MAPK) in NO production and Inos expression in human endothelial cells stimulated by lipopolysaccharide (LPS). Methods: The NO level in the supernatant of the cell culture media was measured with Griess method, expressions of Inos protein and Mrna in vitro cultured endothelial cell line ECV304 were detected with immunofluorescence analysis and reverse transcriptase-PCR respectively. Immunokinase assay was employed to measure P38mapk activity. Results: Compared with the basal level of Inos expression and NO production, the NO level and the expressions of Inos Mrna and protein in the cells were increased after LPS stimulation. P38mapk activity in ECV304 cells exhibited a marked increase at 15 min after LPS stimulation, lasting for about 45 min before gradually decline. The Inos protein and Mrna expressions induced by LPS stimulation was significantly inhibited by SB203580 [4-(4-fluorophenyl)-2-(4- methylsulfinylphenyl)-5-(4-pyridyl) imidazole], a highly specific inhibitor of p38 MAPK. Conclusion: p38 MAPK plays an important role in iNOS expression and NO production in ECV304 cells, and the inhibition of the signal transduction pathway can be effective to reduce the production of iNOS and other cytokines, and therefore constitutes a useful strategy for treating septic shock or inflammation.
目的探讨平滑肌细胞外钙内流对正常膜电位和休克后期超极化膜电位状态的影响。方法制作失血性休克大鼠模型,分离血管平滑肌细胞(ASMCs),用DiBAC4(3)标记细胞膜电位,共聚焦显微镜观察Bay k 8644和TEA对正常对照组和休克组细胞膜电位的影响。结果 Bay k 8644使正常对照组的ASMCs膜电位超极化,而Bay k 8644对休克组 ASMCs膜电位的作用是去极化,但这种作用可被TEA逆转。结论在正常情况下外钙大量内流会激活BKCa使细胞膜电位超极化,而在休克后期外钙内流会直接导致ASMCs膜电位的去极化,对于休克后期低反应性的治疗有重要意义。
