内皮细胞代谢与剪切作用时间的相关性

RELATIONSHIP BETWEEN THE METABOLISM BY CAPILLARYENDOTHELIAL CELLS AND DURATION OF SHEAR STRESS ACTION

应用平行平板流动腔装置研究毛细血管内皮细胞内皮素（ＥＴ）代谢与剪切作用时间的相关关系。将培养的人胚肾小球血管单层内皮细胞置于剪应力分别为０、５×１０－５、１×１０－４和１．５×１０－４Ｎ／ｃｍ２的定常层流中剪切作用２５小时，样品中的ＥＴ分泌量用放射免疫法测定。结果表明，剪切作用时间与内皮细胞ＥＴ的代谢活动有密切相关，ＥＴ分泌量高低不仅取决于剪切应力大小，而且还取决于剪切作用时间长短。ＥＴ分泌量随着剪切作用时间的增减而非线性地增减，在０Ｎ／ｃｍ２、５×１０－５Ｎ／ｃｍ２、１×１０－４Ｎ／ｃｍ２、１．５×１０－４Ｎ／ｃｍ２时ＥＴ累积分泌量最快速最关键的时段分别是流动剪切后７．８－１７．７ｈ、５．３－１６．１ｈ、６．１－１５．６ｈ、８．１－２２．３ｈ；产生最大分泌率时刻相应发生在流动剪切后１２．８ｈ、１０．７ｈ、１０．９ｈ、１５．２ｈ，相应的最大分泌率分别为４５．４１ｐｇ／ｃｍ２．ｈ、４９．１ｐｇ／ｃｍ２．ｈ、７２．５ｐｇ／ｃｍ２．ｈ、３３．５ｐｇ／ｃｍ２．ｈＥＴ累积分泌量和分泌速率随剪切作用时间变化的关系可用Ｌｏｇｉｓｔｉｃ方程来描述。获得了反映ＥＴ分泌规律的大量特征方程和特征数，为了解体内发生于血管壁的病理生?

The parallel plate flow chamber apparatus was established to study the relationship between the endothelin metabolism of capillary endothelial cells and duration of shear stress action. Cultured replicate human glomerulus vascular endothelial cell (HGVEC) monolayers were exposed to steady laminar shear stresses of 0(in a stationary incubation)、5×10-5、 1×10-4 and 1.5×10-4N/cm2 for up to 25 hours, and the ET production was determined by radioimmunoassay.The results demonstrated the existence of a close relationship between duration of shear stress action and the metabolism of ET by HGVEC.The secretion production of ET depends not only on the magnitude of shear stress but also on the duration of shear stress action. The secretion production of ET increases or decreases nonlinearly as duration of shear stress action changes. Time periods of the most quick accumulation of ET for the treatments of 0、5×10-5、1×10-4 and 1.5×10-4 N/cm2 were 7.8-17.7h,5.3-161h,6.1-15.6h,8.1-22.3h,respectively. The corresponding time points producing maximium production rate occurred at 12.8,10.7h,10.9h,15.2h after the start of shear flow,and the corresponding maximium production rate were 45.4、49.1、72.5、33.5 pg/cm2.h,respectively. Logistic equations or polynomial regression equations were used to describe the relationship between the cumulative production and production rate of ET and duration of shear stress action. A lot of specific equations and statistics were obtained to reflect ET secretion in shear flow field. It provided experimental data for better understanding the time course of ET secretion occurred in physiology and pathophysiology of the blood vessel wall.