[Step increase in shear stress effects on releasing prostacyclin of human umbilical vein endothelial cell].

Adopting the flow chamber, we studied the effect of step increase in shear stress on prostacyclin releasing of human umbilical vein endothelial cell (HUVEC). HUVEC monolayer was exposed to step increase in shear stress levels of 1, 10 and 20 dyne/cm2 for 100 minutes. By radioimmunoassay, 6-keto-PGF1 alpha in flowing out liquid from the flow chamber was measured. The results displayed: when HUVEC was not exposed to shear stress, the PGI2 released from HUVEC was not detectable; when HUVEC was exposed to shear stress, the flow onset led to an initial burst increase of PGI2 production rate, which went down subsequently within several minutes. We noticed that the larger the step increase of shear stress became, the higher the peak value of PGI2 production rate ascended, the quicker the peak value subsequently declined, and the higher the average value of PGI2 releasing rate in 80-100 minutes stood. The results demonstrated that in vivo hemorheological factor-the shear stress of blood flowing stimulated the release of prostacyclin from HUVEC.