Vitamin A contents of rat intestinal epithelium and jejunal mucinous adenocarcinoma.

Concentrations of retinol and tetinyl 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 retinyl esters and 303 ng of free retinol/g of wet tissue. The concentration of retinyl 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 microng of retinol equivalents as retinyl esters and 136 microng 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.