Lipid absorption by isolated intestinal preparations

Locusts were fed [1-¹⁴C]-trioleylglycerol alone or mixed with trioleyl-[³H]-glycerol. Thirty minutes after ingestion the intestine was excised and incubated in dilute haemolymph. Lipolysis continued under these conditions. Glycerol was rapidly transported to the haemolymph. The fatty acids were taken up by the mucosa, incorporated into intestinal wall phospholipids, di- and tri-acylglycerols. Considerable amounts of labelled diacylglycerol were released into the haemolymph; fatty acids were also detected in the haemolymph. The ³H ¹⁴C ratio of the intestinal phospholipids and diacyl-glycerol was very similar to that of the haemolymph diacylglycerol. When [³H]-labelled palmitate and [¹⁴C]-glycerol dissolved in buffered saline were pumped through isolated intestinal preparations almost identical results were obtained. Glycerol was rapidly absorbed and palmitate was incorporated into intestinal wall phospholipids and neutral lipids. Both labelled diacylglycerol and fatty acids were detected in the haemolymph lipoproteins.