牛肺动脉单层内皮细胞长度与其血管紧张素II代谢的相关性

用离体培养的牛肺动脉内皮细胞灌流实验研究内皮细胞单层长度与其血管紧张素II代谢的相关性。牛肺动脉单层内皮细胞暴露于剪应力为0.64N/m2 的剪切流中24h后 ,两种不同长度(10cm和6cm)单层内皮细胞的血管紧张素II的平均分泌率有比较显著差异 ,10cm处理的血管紧张素II平均分泌率 (8.61±0.28pg/cm2.h)比6cm处理 (6.14±0.12pg/cm2.h)高40 % ,10cm处理的最小分泌率 (7.55pg/cm2.h)较6cm处理 (5.75pg/cm2.h)高31 % ,10cm处理的最小分泌率出现的剪切时间点比6cm处理要早6个小时。表明牛肺动脉内皮细胞单层长度与其血管紧张素II代谢 (分泌率 )间有密切的相关关系 ,进而从细胞代谢角度间接证实血管内皮细胞膜张应力存在累积效应。

RELATIONSHIP BETWEEN LENGTH OF BOVINEPULMONARY ARTERY ENDOTHELIAL CELLMONOLAYER AND ITS ANGIOTENSIN II METABOLISM

A set of perfusion experiments with a paired bovine pulmonary artery endothelial cell(BPAEC) culture monolayer was utilized to study the relationship between length of cell monolayer and its angiotensin II metabolism. After replicate cultured BPAEC monolayers with two kinds of length of 6cm and 10cm were subjected to the same steady laminar shear stress of 0.64N/m2 for 24 hours, the average production rate of angiotensin II (Ang II) by endothelial cells was significantly different between the two kinds of cell monolayers. The average production rate of Ang II in 10cm group was 1.4-fold (n=26, p<0.01) that in 10cm group (8.61±0.28pg/cm2 vs. 6.14±0.12pg/cm2). The minimum production rate of Ang II in 10cm group was 31 percent higher than that in 6cm group (7.55pg/cm2 vs. 5.75pg/cm2). Correspondent time points occurred at about 11th hours and about 17th hours of flow shear, respectively. The results demonstrated that a close relationship existed between length of endothelial cell monolayer and Ang II metabolism of endothelial cells, indicating the existence of cumulative effect of tensile stress in the upper endothelial cell membrane under the shear flow field.