Changing relative proportions of apolipoproteins CII and CIII of very low density lipoproteins in hypertriglyceridaemia.

The very low density lipoproteins (VLDL) of fasting serum from subjects with normo- and hypertriglyceridaemia (Type IV and V) were separated into subfractions by density gradient centrifugation. The tetramethylurea (TMU)- soluble apolipoproteins were separated by polyacrylamide gel electrophoresis and the relative proportions of apo CII and CIIIs determined. There were highly significant correlations between the concentration of VLDL triglycerides and apo CII (r---0.92), apo CIII1 (r=+0.88) and the ratio apo CII/apo CIII1 (r= --0.94). It was suggested that the decreasing ratio apo CII/CIII1 with increasing triglyceride levels might cause a resistance to lipoprotein lipase and therefore a defect lipolysis of VLDL based upon a changed ratio apo CII/apo CII1 might be part of the pathogenesis of the hypertriglyceridaemia.