Caffeine potentiation of mefenamic acid‐induced lesions in the rat renal medulla

Abstract

The effect of caffeine given in combination with mefenamic acid on the renal medulla was examined. Sprague‐Dawley rats were divided into four groups and gavage fed either suspension (control), mefenamic acid. mefenamic acid + caffeine or caffeine onlu for 4 months. Renal tissue taken from the corticomedullary junction was processed for electron microscopy. Ultrathin sections were cut after identification of vast rectae on survey sections. On subsequent morphometric analysis. percentage interstitial tissue was calculated from the total area of vasa recta less the noninterstitial tissue. The median prcentage of interstitial tissue in the mefenamic acid and caffeine group was 41 (range 33–50; n..