In vitro Incorporation of Fatty Acids in Phospholipids of Intestinal Mucosa.

Abstract

Sinclair, using elaidic acid, found that phospholipids of the intestinal mucosa after feeding fat, contained some of that fed fat. Perlman, Rubin, and Chaikoff later showed that fed, radioactive phosphorus also became incorporated in the phospholipids of the intestinal mucosa. Both of these findings have been repeatedly confirmed. Robinson, et al., have also shown that slices of intestinal mucosa incubated in a Warburg apparatus with radioactive phosphorus would bring about an incorporation of radioactive phosphorus in the mucosal phospholipids. Using the conjugated, unsaturated fatty acids of corn oil as a tagged fat the in vitro incorporation of fatty acids in the intestinal mucosal phospholipids has been studied. Male, albino rats were anesthetized with ether and their abdomens opened. Three cc of an emulsion containing bile salts, lipase (pancreatin), water, and tagged fat was injected into the duodenum and the abdomen closed. After 15 minutes the rats were again etherized and the intestines washed with saline, then alcohol and finally with more saline. After a 15-minute absorption period about 30% of the total fat in the mucosa will be tagged fat. The mucosa of 2 rats was freed from intestinal muscle and immediately placed in a boiling water bath for 5 minutes. The intestines of the other animals were placed in beakers of normal saline and allowed to incubate at room temperature for various lengths of time. In the experiment marked with an asterisk (Table I) the intestines were slit lengthwise and placed in oxygenated, glucose Ringer's at 37°C. There was no alcohol used in washing these intestines. In each case when the incubation time was complete the mucosa was removed and immediately placed in a boiling water bath. The mucosal samples were then frozen, dried and extracted.