American Journal of Clinical Nutrition, Vol 15, 352-357, Copyright © 1964 by The American Society for Clinical Nutrition, Inc.

The Uptake and Distribution of Stearic Acid by Subcellular Components of Intestinal Mucosa

¹ From the Department of Biochemistry, West Virginia University Medical Center, Morgantown, West Virginia

A suspension of stearate 1-C¹⁴ albumin complex was injected into the lumen of isolated small intestinal segments of rats for varying periods of time. The maximum activity in the mucosa occurred 30 minutes after administration of the fatty acid complex. Most of this activity took place in the nuclear plus debris fraction.

Three minutes after injection of the complex, approximately 90 per cent of the absorbed activity existed as unestenified fatty acid. A small but significant amount of labeled fatty acid was esterified. Thirty minutes after administration approximately 75 per cent of the absorbed dose was incorporated into triglycerides. Lesser amounts were found in phospholipids, monoglycerides and diglycerides.

In the early stage of fatty acid absorption all subcellular fractions appeared to be involved in the uptake of fatty acid. The nuclear plus debris fraction contained most of the activity. During the later stages of absorption most of the esterified fatty acid appeared in the nuclear plus debris and soluble fractions. The evidence presented indicates that further study is necessary to characterize the role of the nuclear plus debris component in fat absorption and transport.