1994 Volume 7 Issue 3 Pages 363-370
To study how free radicals affect the vascular endothelium of spontaneously hypertensive rats (SHR), the aorta of 13-week-old male SHR and Wistar-Kyoto rat (WKY) were perfused tert-butyl hydroperoxide (t-BOOH) and the resulting hydrogen peroxide was morphologically examined using cerium lanthanide. The spin trap method revealed a hydroxyl radical adduct at 5 min after t-BOOH perfusion. In t-BOOH-perfused SHR, cauliflower-like blebs were frequently seen on the endothelial cell surface, sometimes with prominent microvilli and marginal folds. Fine granular materials were found clumped or scattered on the surface. On the other hand, blebs and fine granular materials were rarely seen on the cellular surface in t-BOOH-perfused WKY. Transmission electron microscopy accidentally showed a few blebs with electron-dense material only in the intercellular junction in t-BOOH-perfused WKY endothelium. In t-BOOH-perfused SHR, membrane blebs and intracytoplasmic edema were seen in the endothelium. Electron-dense materials were abundant on the surface of the intact and the degenerated endothelium. X-ray spectra showed the cerium peaks, corresponding to the electron dense-material. These findings clearly indicate that free radical injury, especially hydroxyl radical injury, is much more intense in the endothelial cells of SHR than in those of WKY.
