Very low density lipoproteins in intestinal lymph: role in triglyceride and cholesterol transport during fat absorption

作者：Robert K. Ockner, Faith B. Hughes, Kurt J. Isselbacher · 发表于：Journal of Clinical Investigation · 年份：1969 · DOI：10.1172/jci106203 · 被引用次数：182 · 研究领域：Cancer, Lipids, and Metabolism、Cholesterol and Lipid Metabolism、Fatty Acid Research and Health

The role of nonchylomicron very low density lipoproteins (VLDL, S(f) 20-400) in the transport of triglyceride and cholesterol was studied during lipid absorption. Various long chain fatty acids were infused intraduodenally in the form of mixed fatty acid-mono-olein-taurocholate micelles; control animals received saline or taurocholate. As compared with controls, all fatty acids (palmitic, oleic, linoleic) resulted in significant increases in chylomicron (S(f) > 400) triglyceride. In addition, palmitic acid resulted in a twofold increase in VLDL triglyceride, whereas with the absorption of oleic or linoleic acid VLDL triglyceride did not change significantly. Differences in triglyceride fatty acid composition between chylomicrons and VLDL were observed during lipid absorption. Although the absolute amount of endogenous cholesterol in intestinal lymph was not significantly affected by lipid absorption under these conditions, its lipoprotein distribution differed substantially among the lipid-infused groups. During palmitate absorption, VLDL cholesterol was similar to that in the taurocholate-infused controls, and was equal to chylomicron cholesterol. In contrast, during oleate and linoleate absorption the VLDL cholesterol fell markedly, and was less than half of the chylomicron cholesterol in these groups. The half-time of plasma survival of VLDL cholesterol-(14)C was found to be twice that of chylomicron cholesterol-(14)C. These studies demonstrate that dietary long chain fatt...