FECAL AND RECTAL MUCOSAL DIACYLGLYCEROL CONCENTRATIONS AND EPITHELIALPROLIFERATIVE KINETICS

Fecal diacylglycerol (DAG) concentrations have been suggested as bioma rkers for colonic neoplasia because of their potential to be absorbed in the colon and to stimulate epithelial cell proliferation. The inter relationships among nutrient intake, fecal and mucosal DAG, and coloni c proliferative markers have not previously been studied. We designed a pilot study to evaluate the feasibility of evaluating these interrel ationships in 12 volunteers who had a history of colonic adenomatous p olyposis. Total mucosal DAG concentrations were not related to fecal D AG concentrations, but mucosal DAG correlated inversely with the whole crypt labeling index. Dietary intake did not alter fecal DAG concentr ations. However, the percentage of calories from dietary fat correlate d positively with the whole crypt labeling index. Fiber and calcium in take showed a positive correlation with the labeling index in the uppe r 40% of the crypt. The present pilot study failed to demonstrate a co rrelation between dietary components and fecal and total mucosal DAG. Additional studies relating fecal DAG with mucosal proliferation will require the evaluation of DAG concentrations in subcellular compartmen ts of mucosal cells and/or measurement of fecal DAG fatty acid composi tion.