Effects of lipid class and lipid vehicle volume on the intestinal lymphatic transport of DDT

Abstract The effect of lipid vehicle volume and lipid class on the intestinal lymphatic transport of DDT (1,1-bis( p -chlorophenyl)-2,2,2-tri- chlorethane; p , p -DDT) has been investigated in anesthetized rats. Two milligrams of DDT, dissolved in either 50 μ1 or 200 μl of lipid, was infused intraduodenally. The lymphatic transport of DDT was followed by HPLC analysis of hourly lymph samples collected from the intestinal mesenteric lymph duct. Three types of lipid vehicles were utilized in this study, peanut oil (triglyceride), oleic acid (fatty acid) and a 2:1 mixture of oleic acid-monoolein, which represents the lumenal digestion products of a triglyceride. There were major and significant differences in the kinetics of lymphatic transport of DDT and in the cumulative amount of DDT transported when administered in the different lipid vehicles. Cumulative intestinal lymphatic transport of DDT was greatest when administered in either oleic acid or the 2:1 mixture of oleic acid-monoolein. Peanut oil was the least effective lipid vehicle with respect to the lymphatic transport of DDT. A comparison of the lymphatic transport of DDT when administered in the two dose volumes revealed no significant difference in the cumulative transport of DDT within a particular lipid class (triglyceride, fatty acid or oleic acid-monoolein).