477 EFFECTS OF CHOLESTYRAMINE ON SMALL INTESTINAL MUCOSA

Abstract

Cholestyramine (CHOL)is often used successfully in the treatment of diverse diarrheal disorders, yet its effects on small intestinal mucosa have not been evaluated. Accordingly, rat jejunal and ileal segments were studied before and after 3, 6 or 12 days of test diet containing 5% pure CHOL resin in powdered standard lab chow. Weight gain during study was comparable in both CHOL-fed and control groups. For jejunal mucosa, there was no significant difference in wet weight or total DNA content per segment, or in mucosal wet weight or total protein content per mg DNA in any diet period comparing CHOL-treated animals to controls. Similar results were obtained for ileal mucosa, except, at 12 days, mucosal wet weight per segment increased (p<.05) in the CHOL treated rats. Jejunal disaccharidases (U/gm protein) rose significantly after 12 days of CHOL(sucrase:control 74±10 vs CHOL-fed 102±5, p<.02; lactase: control 9.1±0.8 vs CHOL-fed 14.3±0.7, p<.001). Expressing the data as specific activity per segment or per mg DNA gave similar results. Ileal disaccharidases did not change significantly. Conclusions:CHOL feeding for 12 days does not influence jejunal mucosal mass (wet weight), cell number (DNA content) or cell size (mg protein/mg DNA), and has only a small effect on ileal mucosal mass. Jejunal disaccharidase content (U/segment)rises dramatically as does specific activity (U/mg protein, U/mg DNA) suggesting either a direct mucosal effect of CHOL or an alteration of the intraluminal phase sufficient to change brush border enzyme kinetics.