目的旨在观察ＴＭＢ８对血管内皮细胞［Ｃａ２＋］ｉ水平和ＮＯ释放的影响，探讨扩张脑血管的机制。用ＡＲＣＭＭＩＣ阳离子测定系统，测量单个细胞内游离钙浓度（［Ｃａ２＋］ｉ），用血红蛋白法测量一氧化氮（ＮＯ）的释放。结果表明，在细胞外钙浓度为１３ｍｍｏｌ·Ｌ－１时，ＴＭＢ８１２５及２５０μｍｏｌ·Ｌ－１对静息［Ｃａ２＋］ｉ和甲基血红蛋白ΔＥ无明显影响，而５０及１００μｍｏｌ·Ｌ－１时可升高静息［Ｃａ２＋］ｉ和甲基血红蛋白ΔＥ。表明ＴＭＢ８５０及１００μｍｏｌ·Ｌ－１升高脑血管内皮［Ｃａ２＋］ｉ，激活ＮＯ合酶，促进ＮＯ合成和释放，这可能是其扩张脑血管的重要机制之一。 Purpose To observe the effect of TMB8 on [Ca2 +] i level and NO release in vascular endothelial cells and to explore the mechanism of dilation of cerebral blood vessels. The system was used to measure the intracellular free calcium concentration ([Ca2 +] i) with the AR-CM-MIC cation assay and the release of nitric oxide (NO) was measured by the hemoglobin method. The results showed that TMB8125 and 250μmol·L-1 had no significant effect on the resting [Ca2 +] i and methyl hemoglobin ΔE when the extracellular calcium concentration was 13mmol·L-1, 100μmol·L-1 increased resting [Ca2 +] i and methyl hemoglobin ΔE. These results suggest that TMB850 and 100μmol·L-1 elevate [Ca2 +] i in cerebrovascular endothelium, activate NO synthase and promote NO synthesis and release, which may be one of the important mechanisms of its expansion of cerebrovascular.