METABOLISM AND BIOLOGICAL POTENCY OF 5,6-MONOEPOXYVITAMIN A ALDEHYDE IN THE RAT

Abstract

5, 6-Monoepoxyvitamin A (5, 6-MEVA) aldehyde (orally, intra peritoneally or subcut) alleviated deficiency symptoms and promoted growth in vitamin A deficient rats. The aldehyde was reduced to the alcohol primarily in the intestine and esterified to the palmitate ester prior to transport to the liver for storage. 5, 6-MEVA accumulated in liver and other tissues following intraperitoneal administration of 5, 6-MEVA aldehyde; a new visual pigment, with max 480m[mu], was isolated from retinas of rats maintained with 5, 6-MEVA aldehyde. 5, 6-MEVA aldehyde was not converted to the furanoid form, 5, 8-monepoxyvitamin A (5, 8-MEVA) aldehyde, in the stomach. Liver and other tissues of vitamin A deficient rats accumulated 5, 8-MEVA following the oral ingestion of 5, 8-MEVA aldehyde. Enzymatic reduction and oxidation of 5, 8-MEVA aldehyde and esterification of the alcohol were demonstrated.