title: Partitioning of polar fatty acids into lymph and portal vein after intestinal absorption in the rat.
abstract: We tested the hypothesis that fatty acids destined for the portal vein after intestinal absorption would be diverted into lymph when infused along with a saturated long-chain fatty acid. Thoracic fistula rats were infused intraduodenally with either linolenic (18:3), lauric (12:0), or decanoic (10:0) acid, or with each fatty acid in combination with 5 mM palmitic acid (16:0), in micellar solutions of taurocholate (10 mM) and 2-mono-oleoylglycerol. Lymphatic transport of linolenic acid was enhanced by co-absorption with palmitic acid: when 0.1 mM linolenic acid was infused alone, 32 +/- 8% of that absorbed and transported beyond the mesentery was carried in lymph. The addition of palmitic acid to the infusate increased the percentage transported in lymph to 56 +/- 10% (P less than 0.005). The increment was due to enhanced intracellular re-esterification of linolenate into triacylglycerol. When 5 mM linolenic acid was infused, the comparable figures for lymphatic transport were 55 +/- 2% for linolenate infused alone and 66 +/- 6% for linolenate infused with palmitate (P less than 0.005). In contrast, the predominantly portal venous transport of lauric and decanoic acids was unaffected by co-absorption with palmitate. We conclude that the partitioning of long-chain fatty acids between portal blood and lymph is dependent on the luminal milieu, in addition to polarity of the fatty acid and the rate of absorption. Unsaturated long-chain fatty acids have a substantial portal transport under conditions which simulate normal food ingestion.
mesh_terms: D000818:Animals; D004952:Esters / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D007408:Intestinal Absorption; D008042:Linolenic Acids / Q000378:metabolism; D008196:Lymph / Q000378:metabolism*; D008823:Micelles; D010743:Phospholipids / Q000378:metabolism; D011168:Portal System / Q000378:metabolism*; D051381:Rats; D012995:Solubility; D013329:Structure-Activity Relationship; D017962:alpha-Linolenic Acid
chemical_list: D004952:Esters; D005227:Fatty Acids; D008042:Linolenic Acids; D008823:Micelles; D010743:Phospholipids; D017962:alpha-Linolenic Acid