Changes in Lipid Composition of Lymph During Cholesterol Absorption in the Rat

Publisher Website
Google Scholar
Abstract
Time studies of the appearance of lipid fractions in the thoracic duct lymph of rats were performed following the administration of emulsions containing cholesterol, oleic acid and sodium taurocholate. The influence of added protein on lipid levels and the total nitrogen of lymph was also studied. Addition of albumin to administered saline was without effect on lymph flow, lipid fractions or total nitrogen. In those animals receiving cholesterol, oleic acid and taurocholate, in addition to albumin, a rapid increase in total lipid was evident during the initial 3 hours, followed by a gradual fall in this fraction to near preabsorptive levels at the end of 9 hours. Comparable changes were observed in the ester cholesterol, neutral fat and phospholipid fractions. Animals receiving a similar emulsion lacking albumin displayed less marked increases in the lipid fractions which were, however, prolonged throughout the experimental period. In contrast to the other lipid fractions in this group, the amount of lymph cholesterol for the 24-hour period was significantly greater than in the comparable group receiving albumin. During cholesterol absorption in both experimental groups, the increase in total lymph cholesterol was attributable almost entirely to an increase in the esterified fraction, which comprised between 84 to 92% of the absorbed sterol.