Uptake, during Absorption, of Free Fatty Acids by Phospholipids of the Intestinal Mucosa of Rats

Abstract

SEVERAL authors have suggested that the phospholipids may participate in the absorption of fats^1–3. However, an examination of the ³²P turnover in the phospholipids of the mucosa of dogs and rats led Zilversmit et al.^4,5 to conclude that these compounds are of little significance in this process. More recently, from the results of ³²P-turn-over in experiments with everted intestinal sacs of golden hamsters, Johnston and Bearden⁶ have suggested that the phosphatidic acid might be an intermediate in the transport of fatty acids during absorption. But these claims could not be confirmed by Gurr et al.⁷, who studied the ³²P turnover of the intestinal phospholipids of living rats. It is clear that in all these experiments labelled ³²P was used and no attempt was made to investigate the uptake of free fatty acids by the mucosal phospholipids; we have found that the mucosal phospholipids rapidly take up the free fatty acid from the lumen of the small intestine.