Rate of Fat Uptake by Intestinal Lymphatics.

Abstract

SummaryMeasurements of the rate of fat uptake by the intestinal lymphatics showed that when dogs were fed 25 g of olive oil by mouth the total lipids in the thoracic duct lymph remained elevated above fasting levels for more than 24 hours. When the olive oil was introduced directly into the duodenum, the lymph was cleared of excess lipid in 13 hours. That the excess lipid in postcibal lymph probably represents fat which has been directly contributed by absorption from the intestine was shown by the failure to observe a significant increase in thoracic duct lymph lipid content in response to infusing a large volume of milky chyle intravenously. These results suggest that absorption of fat continues for more than 24 hours after its oral administration and is associated with a slow and prolonged delivery of fat by the stomach into the upper intestine. Stomach-fed dogs returned a significantly higher percentage of the fed fat in the lymph in 24 hours than did duodenum-fed dogs suggesting that the retention of...