Isolated rabbit enterocytes as a model cell system for investigations of chylomicron assembly and secretion

A method is described for the isolation of viable enterocytes from rabbit s mall intestine. The procedure can also be used to isolate populations of ep ithelial cells from the crypt/villus gradient. The isolated enterocytes syn thesized and secreted apoB-48 and triacylglycerol in particles of the densi ty of chylomicrons. Secretion was stimulated by addition of bile salt/lipid micelles. Pulse-chase experiments demonstrated that newly synthesized apoB -48 is degraded intracellularly and that degradation is inhibited by provis ion of Lipid micelles, suggesting that regulation of chylomicron assembly a nd secretion is broadly similar to that of very low density lipoprotein ass embly in hepatocytes. This procedure for preparation of isolated enterocyte s will provide a useful model system for investigation of the molecular det ails of chylomicron assembly.