PARTITION OF OLEIC-ACID BETWEEN THE LYMPH AND PORTAL BLOOD IN RATS HAVING A DIVERTED BILE-PANCREATIC DUCT

The present study examines the suggestion that in the absence of adequ ate bile and pancreatic juice, which support the absorption from the g ut of long-chain fatty acids into lymph, the fatty acids are absorbed directly into the portal blood, Oleic acid (18:1) partitioning between lymph and portal blood was investigated in intact and bile- and pancr eatic juice-diverted rats, In a first set of experiments, 18:1 absorpt ion from the gut into lymph and blood was studied by continuous recove ry of the mesenteric lymph for 6 h and mesenteric portal venous blood for 1 h, In a second set of experiments, esterification processes were investigated by study of the mucosal distribution of labelled lipids and by mono- and diacylglycerol acyltransferase (EC 2.3.1.22 and EC 2. 3.1.20 respectively) specific activities, In the bile- and pancreatic juice-diverted rats the absorption of labelled 18:1 into lymph was sig nificantly reduced during the first 3 h of intraluminal infusion of th is substrate, In such rats a compensatory absorption of labelled 18:1 into mesenteric portal blood was not observed, At 6 h after micellar l ipid-mixture infusion, the overload of lipids both in free form and as triacylglycerols persisting in the mucosa paralleled the lower acyltr ansferase specific activities observed in bile- and pancreatic juice-d iverted rats, These studies demonstrate the absence of a previously pr oposed compensatory absorption of 18:1 into portal blood when absorpti on into lymph is impaired by an inadequate supply of bile and pancreat ic juice.