AUTOANTIBODIES AGAINST ARTERIAL ANTIGENS - CHARACTERIZATION BY ELISA AND IMMUNOBLOT ANALYSIS IN THE SPONTANEOUSLY HYPERTENSIVE RAT

The presence of autoantibodies directed against arterial antigens in s erum samples from spontaneously hypertensive rats and related controls that included Wistar-Kyoto and Sprague-dawley rats were assayed by en zyme-linked immunosorbent assay and immunoblotting technique. Circulat ing immunoglobulin G antibodies reactive against arterial antigen, as measured by enzyme-linked immunosorbent assay, could be detected in se rum samples of 26 of 30 spontaneously hypertensive rats (87%) and 8 of 30 (27%) Wistar kyoto rats. These antibodies (Abs) were not detectabl e either by enzyme-linked immunosorbent assay or immunoblotting in ser a from Sprague-dawley rats. The arterial antigen-reactive-antibody was antigen specific, because the binding reactivity was absorbed by arte rial antigen but not by fibroblasts or peripheral blood mononuclear ce lls. Immunoglobulin G arterial antigen-reactive antibody was significa ntly higher in adult spontaneously hypertensive rats with established hypertension, compared with young prehypertensive rats or normotensive wistar kyoto rats. Immunoblotting of spontaneously hypertensive rats sera revealed reactivity of arterial antigen-reactive antibody against arterial antigen ranging in size from 20 to 97 kDa. Sera from Wistar kyoto rats recognized arterial antigen ranging in size from 40 to 90 k Da. A significant correlation (p <0.004) was found between adult spont aneously hypertensive rats with established hypertension and the prese nce of arterial antigen-reactive antibody reactivity against arterial antigen of 20, 69 and 97 kDa. Antibody directed against a 20 kDa arter ial antigen was detected in both young prehypertensive rats and adult rats with established hypertension but not in Wistar kyoto or Sprague- dawley rats. Antibodies directed against both 69 and 97 kDa arterial a ntigens were detected only in spontaneously hypertensive rats sera. Th ese data show that the pattern of arterial antigen-reactive antibody r eactivity in sera of hypertensive rats is heterogeneous, and suggest t hat arterial antigen-reactive antibody directed against few arterial a ntigens may be involved in the pathogenesis of hypertension in the spo ntaneously hypertensive rat.