SHEAR-STRESS INCREASES THE RELEASE OF INTERLEUKIN-1 AND INTERLEUKIN-6BY AORTIC ENDOTHELIAL-CELLS

Background. The aim of this study was to determine the correlation bet ween shear stress and the release of interleukin-1 (IL-1) and interleu kin-6 (IL-6) by endothelial cells (EC). Methods. Bovine aortic EC were seeded in fibronectin-coated cylinders at 1.0 X 10(6) cells/tube and allowed to reach confluence and to adhere for 48 hours. The experiment al groups were subjected to a laminar flow of 100 ml/min (6 dyne/cm2). The control group was subjected to similar incubation conditions with out flow. The release of IL-1 and IL-6 by EC was measured by enzyme-li nked immunosorbent assay. Results. Shear stress increased significantl y (p < 0.01) the release of IL-1 and IL-6 by EC. The release of these two cytokines had different kinetics. Conclusions. Increasing shear st ress facilitates release of IL-1 and IL-6 by EC. Previous reports have shown that IL-1 and IL-6 promote vascular smooth-muscle cell prolifer ation. Thus abnormal flow conditions with increasing shear stress may predispose to smooth-muscle cell proliferation that characterizes earl y atherosclerotic plaque development by an interleukin-mediated mechan ism.