血管内皮细胞对平滑肌张力的保护作用

Protective Action of the Vescular Endothelial Cells on Tension of the Smooth Muscle

血管平滑肌的张力与内皮细胞相关。用去甲肾上腺素（ＮＥ，１μｍｏｌ／Ｌ）灌流大鼠有、无血管内皮细胞的离体胸主动脉条标本，结果有血管内皮细胞标本的张力上升幅度小于无内皮细胞标本；洗脱ＮＥ后有内皮细胞标本的张力下降速率明显大于无内皮细胞标本。用乙醇（１０％）浸泡标本１ｈ，重复加ＮＥ实验，结果有血管内皮细胞标本的张力上升幅度大于无内皮细胞标本（Ｐ＜０．０５）。提示血管内皮细胞释放的活性物质不仅影响平滑肌的收缩过程，也影响其舒张过程。血管内皮细胞对平滑肌张力有保护作用。

The tension of the vascular smooth muscle related with endothelium.two types of vascular strip were prepared from thoracic aorta of the rat. The vascular endotheium was intact in one group and removed in the other. The two types of preparations were superfused respectively with norepinephrine(1 μmol/L). The tension increment of vascular strip with intact endothelium was smaller than with removed endothelium.After washing away NE,the rate of the tension decrement with intact endothelium was more than that with removed endothlium.The two types of vascular strips after bathed in 10 % alcohol for one hour,were superfused respectively with NE ,the tension increment with intact endothelium was more marked than without endothelium (P <0. 05). Our data suggest that the active substance delivered by vascular endothelial cells not only influences the contraction process of smooth muscle ,but also influences its the vasdilator process,and proteced the tension of vascular smooth muscle.