The transport of endogenous lipids in the lipoproteins of mesenteric lymph was studied in fasting rats with mesenteric lymph fistulas. The lymph was found to contain, in addition to chylomicrons (Sf >400), a significant amount of another, more dense, triglyceride-rich fraction, the very low density lipoproteins (VLDL), which showed a peak Sf of 102. The VLDL differed from chylomicrons not only in flotation, but also in per cent lipid composition and electrophoretic mobility in agarose gel. The VLDL fraction was found to contain 47% of the triglyceride and 54% of the cholesterol of fasting lymph and, in the fasting state, was the major lipoprotein species present.
Robert K. Ockner, Faith B. Hughes, Kurt J. Isselbacher