| 1. |
- Barros, H, et al.
(författare)
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Arachidonic acid absorption in human jejunum in organ culture : effects of ethanol
- 1990
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Ingår i: European Journal of Clinical Investigation. - : Wiley. - 0014-2972. ; 20:5, s. 10-506
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Tidskriftsartikel (refereegranskat)abstract
- Human jejunal tissue obtained by peroral biopsy was cultured in control medium and in medium containing 100 mmol l-1 ethanol. Subsequently, the incorporation and metabolism of [3H]-arachidonic and [14C]-linoleic acid were evaluated. Of the two fatty acids a significantly higher amount of [3H]-arachidonic acid was incorporated into phospholipids and more [14C]-linoleic acid was incorporated into triacylglycerols. This preferential distribution of the labelled fatty acids was not affected by ethanol, but when ethanol was present in the tissue culture medium, there was a significant decrease in the incorporation of both fatty acids into tissue phospholipids. The study thus shows that ethanol in moderate concentrations can affect human jejunal absorption and metabolism of polyenoic fatty acids, contributing to a decrease in the amount of eicosanoid precursors available in jejunal tissue.
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| 2. |
- Barros, H., et al.
(författare)
-
Hydrolysis of phosphatidylinositol by human panreatic phospholipase A2
- 1990
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 25:2, s. 134-140
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Tidskriftsartikel (refereegranskat)abstract
- Pure human pancreatic phospholipase A2 efficiently hydrolyzed the 2-ester bond of 14C-2-linoleoyl and 14C-2-arachidonyl phosphatidylinositol (PI). The rate of hydrolysis varied markedly with the bile salt (sodium taurocholate to sodium taurodeoxycholate, 3:4 mol/mol) concentration, the hydrolysis being decreased with increasing bile salt to PI ratio. The influence of bile salts was thus similar to that which has earlier been described for the hydrolysis of phosphatidylcholine (PC) with pig pancreatic phospholipase A2. When 2-3H-arachidonyl PC and 2-14C-arachidonyl PI were incorporated into a mixed substrate, PI was hydrolyzed even faster than PC, the hydrolysis of both phospholipids varying in the same manner with bile salt concentration. 2-14C-arachidonyl PI was also efficiently hydrolyzed by human duodenal content, although at a somewhat slower rate than 2-3H-arachidonyl PC. It is concluded that PI is a good substrate for human phospholipase A2. This minor but arachidonate-rich dietary phospholipid may thus be digested and absorbed by pathways similar to those of the major dietary and bile phospholipid, phosphatidylcholine.
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