Metabolism of vicine and convicine in rat tissues: absorption and excretion patterns and sites of hydrolysis.

Abstract

AbstractThe objectives of this study were to determine whether dietary vicine and convicine were absorbed by rat tissue, and to determine their excretion patterns and/or sites of degradation. Orally administered vicine and convicine were excreted in relatively low amounts via the kidney and faeces. However, no vicine or convicine was detected in the blood, liver, kidney or muscle tissue of rats which had been fed these compounds. In‐vitro studies demonstrated that vicine and convicine were not hydrolysed in liver, kidney, muscle, caecal wall or intestinal wall homogenates. In contrast, digesta samples from the large intestine and caeca were able to rapidly hydrolyse these compounds, with the concomitant formation of new compounds. Digesta from the stomach and small intestine promoted the slow hydrolysis of these compounds, as did fresh faecal samples. These results would suggest that vicine and convicine are absorbed by the rat in only limited amounts, are not hydrolysed by rat tissues, and are rapidly cleared from tissue via the kidney. The bulk of the dietary vicine and convicine are hydrolysed in the large intestine and caecum.