Apolipoprotein B (apoB) Concentrations in Lipoproteins in Cows

Abstract

The concentrations of apolipoprotein B (apoB)-48 and apoB-100 in triglyceride-rich lipoproteins (TRL), intermediate density lipoprotein (IDL), and low density lipoprotein (LDL) fractions separated by gel permeation chromatography were determined in Holstein and Japanese black cows by enzyme-linked immunosorbent assay (ELISA). A significant correlation (p<0.01) was observed between apoB-48 in TRL and plasma triglyceride (TG) levels in both Holstein and Japanese black cows. Additionally, apoB-48 in TRL and plasma TG levels in Holstein cows were significantly lower (p<0.01) than those in Japanese black cows. These results suggested that TG derived from intestinal (exogenous) TRL rather than from liver (endogenous) TRL was the major source of milk fat.