Vitamin A Contents of Rat Intestinal Epithelium and Jejunal Mucinous Adenocarcinoma 2 3

Abstract
Concentrations of retinol and retinyl esters were assayed in rat intestinal mucosa and in chemically induced transplanted mucinous adenocarcinoma of the jejunum. Lipid extract from the tissues was chromatographed on deactivated alumina to Isolate retinol and retinyl esters, which were determined by specific spectrofluorometry. Normal intestinal mucosa tissue contains 556 ng of retinol equivalents as retlnyl esters and 303 ng of free retinol/g of wet tissue. The concentration of retlnyl esters in the intestinal mucosa from rats carrying the transplanted tumor was 341 ng/g wet tissue; no free retinol was detected in the small intestinal epithelium of these rats. Liver tissue from the tumor-bearing rats contained 157 µg of retinol equivalents as retinyl esters and 136 µg of free retinol/g of wet tissue. The concentration of vitamin A per cell in the adenocarcinoma tissue was about 20 times less than that In intestinal epithelium.