Vitamin E Did Not Prevent Platelet Activation, but Prevented Increase of Lipid Peroxides and Renal Dysfunction in DOCA-Salt Hypertensive Rats

Abstract

Changes in platelet aggregability patterns and lipid perox-ide levels and their relationship were examined in DC CA-salt hyperten-sive rats during the development of hypertension. In addition, the effect of vitamin E treatment on those changes was also investigated. The blood pressure of the hypertensive rats was 188, 201, 212mmHg on day 11, 17, and 23, respectively. In the hypertensive rats, both aggregability and granule content in platelet decreased on day 12, 18, 24, and marked decreases were observed on day 24. These data suggested the appearance of exhausted platelets, which had been already activated in vivo due to the hypertension. Marked increases in lipid peroxide levels in serum, the heart and the kidney were observed on day 24 in the hypertensive rats. Increase in serum urea nitrogen was also observed in the hypertensive rats on day 24, suggesting the dysfunction of the kidney. Vitamin E treatment did not prevent in vivo platelet activation due to hypertension, but greatly prevented the elevations of lipid peroxides in serum, the heart and the kidney, and serum urea nitrogen. These results suggested that in vivo platelet activation, an increase of lipid peroxides, and renal dysfunction occur in this order due to hypertension, and that the latter two are significantly prevented by vitamin E treatment.