HEPATIC-CLEARANCE OF CHYLOMICRON REMNANTS IN MICE LACKING APOPROTEIN-E

Control and apoprotein E-deficient mice generated by gene targeting in embryonic stem cells were fed a fat load containing H-3-labeled retin ol and the absorbed radioactivity present in the plasma, liver, and ca rcass measured 6 h later. The radioactivity in the plasma of the apopr otein E-deficient mice was several fold higher than in control animals , but it accounted for less than 1/5 of the absorbed radioactivity. In both groups of animals most of the absorbed radioactivity was recover ed in the livers. These findings indicate that in apoprotein E-deficie nt mice chylomicron remnants can be taken up by the liver by a process that does not require the mediation of apoprotein E.