Effect of vitamin E-deficiency on renin release was examined with rat kidney cortical slices. Male Wistar rats were fed either a control or a vitamin E-deficient diet for 4 weeks. When kidney cortical slices were incubated in a Krebs-Ringers' bicarbonate solution (pH 7.4) at 37 degrees C, the rate of renin release into the incubation medium in vitamin E-deficient group was significantly higher than that in the control group. However, dietary supplementation of alpha-tocopheryl acetate (TOCA) or N,N'-diphenyl-p-phenylenediamine (DPPD) to the vitamin E-deficient rats for 5 d suppressed the stimulation of renin release from kidney cortical slices by vitamin E-deficiency. On the other hand, the release of protein, acid phosphatase and alkaline phosphatase during incubation of kidney cortical slices was not affected by vitamin E-deficiency or supplementations of TOCA and DPPD. These findings indicate that vitamin E-deficiency specifically stimulates renin release from kidney cortical slices and this effect is attenuated by the dietary supplementation of TOCA or DPPD.