Lipids of gastric secretion in patients with cystic fibrosis

Abstract

Lipids were investigated in gastric secretions of patients with cystic fibrosis and of normal individuals. Organic extracts from dialyzed and lyophilized samples were fractionated on silicic acid columns into neutral lipids, glycolipids and phospholipids. The lipids contained in each fraction were separated into individual components by thin-layer chromatography and quantitated. The gastric secretions of patients with cystic fibrosis contained 80–140% more lipids than those of normal individuals, exhibited an elevated level of neutral lipids and contained alkylglycerols and alkylacylglycerols. The level of glycolipids was higher in normal gastric secretions. The phospholipids of cystic fibrosis secretions exhibited about 50% lower content of lysophosphatidylcholine, lysophosphatidylethanolamine and lysophosphatidylserine. The glycosphingolipids of both types of samples contained mono-, di- and trihexosylceramides. The major glyceroglucolipid of normal gastric secretions was tetraglucosyl glyceroglucolipid, whereas hexa- and octaglucosyl glyceroglucolipids were predominant in cystic fibrosis samples. The sulfated glyceroglucolipids in cystic fibrosis samples were lower than those of normal secretions and represented only 4–37% of total glyceroglucolipid, whereas in normal secretion sulfated glyceroglucolipids averaged 50–62%.