Plasma Lipoprotein Profile in Fasted and Refed Chickens of Two Strains Selected for High or Low Adiposity

Publisher Website
Google Scholar
Abstract
The plasma lipoprotein profile has been determined in fasted and refed 5-week-old male broilers selected for low or high adiposity. Lipoprotein classes were subfractionated by density gradient ultracentrifugation, appearing as distinct bands with the following densities: very low density lipoprotein (VLDL), d < 1.013 g/ml; low density lipoprotein (LDL), d 1.023–1.046 g/ml and high density lipoprotein (HDL), d 1.052–1.130 g/ml; the physicochemical characteristics (chemical composition, electrophoretic mobility and particle size) of these particles were then assessed. HDL, seen as a single band, represented 80% of total lipoproteins, with VLDL and LDL accounting for 1% and 16%, respectively, in fasted birds. Lipoprotein profiles were similar in fasted and refed animals of both lines, with the exception that VLDL levels were some 14-fold and 7-fold higher in the lean and fat lines, respectively, in the refed state. The VLDL of fasted birds of both lines were enriched in protein and relatively homogeneous in size; by contrast, VLDL in the refed state contained more triglyceride and less cholesteryl ester and protein and were larger and more heterogeneous, possibly representing a mixture of portomicrons and VLDL of hepatic origin. Birds of the fat line in both nutritional states differed from lean birds in exhibiting elevated plasma lipid and lipoprotein [VLDL, intermediate density lipoprotein (IDL) and HDL] levels, evidence that liver activity is directed toward increased lipoprotein production and secretion in that line.