Quantification of human plasma apolipoproteins C-I, C-II, and C-III by radioimmunoassays.
We have developed radioimmunoassays for the quantification of apolipoproteins (apo) C-I, C-II, and C-III in human plasma. The apo C proteins were isolated from very low-density lipoproteins of patients with hypertriglyceridemia, fractionated on a Sephacryl column, and purified by diethylaminoethyl cellulose anion-exchange chromatography followed by reverse-phase fast protein liquid chromatography. The assays were sensitive, specific, and reproducible, and the standards demonstrated parallel immunoreactivity with plasma samples. Patients with hypertriglyceridemia (triglyceride level more than 2,200 mg/liter)--14 patients with diabetes and 12 with type V hyperlipoproteinemia--were compared with age- and sex-matched control subjects. In comparison with the control groups, levels of apoproteins C-I, C-II, and C-III were significantly increased in both disease groups, but the ratios of the C peptides to triglycerides were significantly lower, an indication of a relative deficiency of C apoproteins in hypertriglyceridemic states. Independent radioimmunoassays for each of the C apolipoproteins would help to study their individual roles in triglyceride-rich lipoprotein metabolism.
Bren
N D
ND
Atherosclerosis Research Unit, Mayo Clinic Rochester, MN 55905.
Rastogi
A
A
Kottke
B A
BA
D000328:Adult; D000368:Aged; D053302:Apolipoprotein C-I; D053304:Apolipoprotein C-II; D053305:Apolipoprotein C-III; D001056:Apolipoproteins C / Q000097:blood*; D003920:Diabetes Mellitus / Q000097:blood; D005260:Female; D006801:Humans; D006953:Hyperlipoproteinemia Type IV / Q000097:blood; D006954:Hyperlipoproteinemia Type V / Q000097:blood; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D053302:Apolipoprotein C-I; D053304:Apolipoprotein C-II; D053305:Apolipoprotein C-III; D001056:Apolipoproteins C