Independent regulation of plasma apolipoprotein C-II and C-III concentrations in very low density and high density lipoproteins: implications for the regulation of the catabolism of these lipoproteins.
Apolipoproteins C-II (apoC-II) and C-III (apoC-III) are distributed among all the major lipoprotein classes, particularly very low density (VLDL) and high density lipoproteins (HDL). We have determined concentrations of apoC-II and apoC-III in VLDL and HDL in subjects with a wide range of VLDL triglyceride and HDL cholesterol levels, and correlated these levels with fractional catabolic rates (FCR) of VLDL triglyceride and HDL apolipoprotein A-I (apoA-I). Both apoC-II and apoC-III levels increased in VLDL as VLDL apolipoprotein B (apoB) and triglyceride levels rose. The rate of rise of VLDL apoC-III, however, was approximately 3 times greater than that of apoC-II, and positive correlations were present between the ratio of VLDL apoC-III/apoC-II and both VLDL apoB (r = 0.59; P less than 0.01) and VLDL triglyceride (r = 0.70; P less than 0.005) levels. Univariate analysis demonstrated that the FCR for VLDL triglyceride was inversely related to the ratio of apoC-III/apoC-II in VLDL (r = -0.58; P less than 0.05), although this relationship was not significant in a multivariate analysis. In HDL, concentrations of apoC-III and apoA-I were correlated (r = 0.73; P less than 0.005) while no correlation was observed between apoC-II and apoA-I levels. Univariate analyses of HDL variables revealed inverse correlations between the concentration of apoC-III and the FCR for apoA-I (r = -0.67; P less than 0.005) and between the ratio of apoC-III/apoA-I and the FCR for apoA-I (r = -0.66; P less than 0.005). Multivariate analysis confirmed the latter relationship.(ABSTRACT TRUNCATED AT 250 WORDS)
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Department of Biomathematics and Biostatistics, Mount Sinai School of Medicine, New York, NY.
Gibson
J C
JC
Ginsberg
H N
HN
D000328:Adult; D053304:Apolipoprotein C-II; D053305:Apolipoprotein C-III; D001056:Apolipoproteins C / Q000097:blood*; D005260:Female; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood*; D008079:Lipoproteins, VLDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood
D053304:Apolipoprotein C-II; D053305:Apolipoprotein C-III; D001056:Apolipoproteins C; D008075:Lipoproteins, HDL; D008079:Lipoproteins, VLDL; D014280:Triglycerides