Abstract
It was reported that type III hyperlipoproteinemia showed characteristic lipoprotein changes, namely appearance of β-VLDL, and an increase of cholesterol and apoprotein E and deficiency of apoprotein E3 in VLDL. In the cholesterol fed guinea pig, plasma lipoprotein feature was similar of human type III hyperlipoproteinemia. In the present study, plasma lipoprotein changes and isoelectric focussing pattern of apo VLDL in control and cholesterol fed guinea pig were reported. Control guinea pigs were fed with commercial chow and cholesterol group animals were fed with the same basal diet added 1% cholesterol and 5% coconut oil for 2 weeks. In the cholesterol guinea pigs cholesterol in VLDL was increased (Fig. 1), agarose gel electrophoretogram of serum showed broad β band (Fig. 2) and apoprotein E in lipoprotein fractions was increased. (Fig. 3) The analytical ultracentrifugation of IDL and LDL (d: 1.006-1.063) showed increase of IDL and LDL in cholesterol fed guinea pigs as compared to control. (Fig. 4) The isoelectric focussing pattern of apo E was identified to six bands, and apo C was four. As compared with human, the first and second band from the cathod were correspond to apo E3 and E2 respectively, and the former was markedly diminished in both control and cholesterol group. (Fig. 5, 6) From these results it was suggested that the metabolism of VLDL remnant in guinea pigs was similar to that of human type III hyperlipoproteinemia. Guinea pig was considered to be a good animal model for studying human type III hyperlipoproteinemia.
