Effects of colchicine on the intestinal transport of endogenous lipid

The involvement of microtubules in the transepithe-JiaJ transport of exogenous lipid in intestinal absorptive cells has been suggested.Using electronmicroscopic, biochemical, and radiochemical methods, we have studied the effects of the antimicrotubular agent colchicine on the intestinal mucosa and on the intestinal transport of endogenous lipid of rats in the fasting state.After colchicine treatment, the concentration of triglycerides in intestinal mucosa of rats fasted for 24 h doubled, and electron microscopic studies showed a striking accumulation of lipid particles in absorptive epithelial cells of the tips of jejunal viJJi.These findings suggest that colchicine interferes with the intestinal transepithelial transport of endogenous lipoproteins.Additional studies, using an intraduodenal pulse injection of [14C]Jino-Jeic acid, showed that colchicine does not affect the uptake of fatty acids by intestinal mucosa.However, it had divergent effects on fatty acid esterification, enhancing their incorporation into triglycerides relative to phospholipids, and caused a significant accumulation of endogenous diglycerides, triglycerides, and cholesterol esters within the absorptive intestinal epithelium.Detailed ultrastructural and morphometric studies revealed a decrease of visible microtubules, and a displacement of the smooth and rough endoplasmic reticulum and GoJgi apparatus.