Systemic hypertension produces pericyte changes in retinal capillaries

摘要: PURPOSE The purpose of this study was to examine retinal capillaries and their pericytes that previous research suggests be contractile. A contractile role regulating capillary blood flow may more apparent when the vasculature is subjected stress systemic hypertension. METHODS Using ultrastructural morphometry myosin subfragment-1 technique, normal hypertensive rats were measured at three different time points, early, intermediate, late (24, 44, 68 wk). RESULTS Hypertensive seemed dilate early point (P = 0.002), constricted intermediate < 0.001), did not redilate later. Wall thickness enlarged all times, pericyte coverage (the ratio plasma membrane length in contact with vascular circumference outer endothelial tube) greater total area viable cytoplasm relative vessel wall increased (all P 0.001). Also, time, circumferential tube by actin filament bundles within had CONCLUSIONS These data indicate effects hypertension extend into bed, causing change increase constriction. They represent first vivo indirect evidence morphologic criteria for contractility disease.