EFFECT OF VITAMIN E-DEFICIENCY ON RENIN RELEASE FROM RENIN GRANULES

Abstract

This study was undertaken to investigate the effects of vitamin E-deficiency on renin release from isolated renin granules. Male Wistar rats were fed either a control or a vitamin E-deficient diet. Renin granules were prepared from the kidney cortex homogenate by a discontinuous sucrose density gradient centrifugation. Renin activity was measured by radioimmunoassay and lipid peroxidation was estimated by means of the thiobarbituric acid test. The intake of vitamin E-deficient diet for 4 weeks resulted in a decrease in α-tocopherol content in renin granules, accompanied by an increased level of endogenous lipid peroxides. When the renin granules were incubated at 37°C, the rate of renin release from the granules in vitamin E-deficient group was significantly higher than that in the control group. These results indicate that vitamin E exists in renin granule membranes and functions in maintenance of membrane integrity by blocking the lipid peroxidation.