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Early steps of Eicosanoid precursor absorption and tissue distribution.

Melin, Tor LU (1997)
Abstract
Eicosanoids are important for a wide range of physiological and pathophysiological processes.How their essential fatty acid precursors are absorbed and tissue distributed is not well charactherized. When given orally to rats, arachidonic acid (20:4) was retained in the small intestine to a larger extent than linoleic acid (18:2).More 20:4 than 18:2 was incorporated in phospholipids (PL) of the small intestine, with the strongest preference for phosphatidyl ethanolamine and phosphatidyl inositol. More of the 20:4 than of 18:2 was directed to the liver. Essential fatty acid deficient (EFAD) rats had an increased incorporation of 18:2 in all tissues, and an increased PL incorporation of both 20:4 and 18:2 compared to controls. EFAD human... (More)
Eicosanoids are important for a wide range of physiological and pathophysiological processes.How their essential fatty acid precursors are absorbed and tissue distributed is not well charactherized. When given orally to rats, arachidonic acid (20:4) was retained in the small intestine to a larger extent than linoleic acid (18:2).More 20:4 than 18:2 was incorporated in phospholipids (PL) of the small intestine, with the strongest preference for phosphatidyl ethanolamine and phosphatidyl inositol. More of the 20:4 than of 18:2 was directed to the liver. Essential fatty acid deficient (EFAD) rats had an increased incorporation of 18:2 in all tissues, and an increased PL incorporation of both 20:4 and 18:2 compared to controls. EFAD human HepG2 cells had an increased delta-6- and delta-5-desaturase activity. Both enzymes had a rate limiting function.Chylomicron 20:4- and 20:5-diacylglycerol esters were resistant to in vitro incubations with lipoprotein lipase (LPL) but not to hepatic lipase.18:2 and other shorterchain fatty acid esters were not LPL resistant. When 20:4 was injected intravenously to rats, 8% of the dose was secreted in the bile during 24h. Diverting the bile with a drain decreased the recovery of small intestinal 20:4 by 75%, but did not decrease the recovery in stomach and colon. The pools of 20:4 injected i.v. in albumin bound form and injected esterified in chylomicrons did not equilibrate even after 96 h. The selective chanelling of 20:4 to the liver via chylomicrons, and biliary secretion, points to an enterohepatic circulation of 20:4. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Prof Vessby, B., Uppsala University
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Lipids, mebran, steroider, Lipider, steroids, membranes, Gastro-enterology, Gastroenterologi
pages
148 pages
publisher
Gastroenterology Division, Dept Internal Medicine, University Hospital, S-221-85 Lund, Sweden
defense location
Lecture Hall 3, Univ. Hosp. Lund
defense date
1997-05-28 10:15
external identifiers
  • Other:ISRN: LUMEDW / MEMA-97(1047)-SE
language
English
LU publication?
yes
id
5395e9cf-e17a-499a-8d0e-fc692414ec68 (old id 29302)
date added to LUP
2007-06-13 14:48:39
date last changed
2016-09-19 08:45:13
@misc{5395e9cf-e17a-499a-8d0e-fc692414ec68,
  abstract     = {Eicosanoids are important for a wide range of physiological and pathophysiological processes.How their essential fatty acid precursors are absorbed and tissue distributed is not well charactherized. When given orally to rats, arachidonic acid (20:4) was retained in the small intestine to a larger extent than linoleic acid (18:2).More 20:4 than 18:2 was incorporated in phospholipids (PL) of the small intestine, with the strongest preference for phosphatidyl ethanolamine and phosphatidyl inositol. More of the 20:4 than of 18:2 was directed to the liver. Essential fatty acid deficient (EFAD) rats had an increased incorporation of 18:2 in all tissues, and an increased PL incorporation of both 20:4 and 18:2 compared to controls. EFAD human HepG2 cells had an increased delta-6- and delta-5-desaturase activity. Both enzymes had a rate limiting function.Chylomicron 20:4- and 20:5-diacylglycerol esters were resistant to in vitro incubations with lipoprotein lipase (LPL) but not to hepatic lipase.18:2 and other shorterchain fatty acid esters were not LPL resistant. When 20:4 was injected intravenously to rats, 8% of the dose was secreted in the bile during 24h. Diverting the bile with a drain decreased the recovery of small intestinal 20:4 by 75%, but did not decrease the recovery in stomach and colon. The pools of 20:4 injected i.v. in albumin bound form and injected esterified in chylomicrons did not equilibrate even after 96 h. The selective chanelling of 20:4 to the liver via chylomicrons, and biliary secretion, points to an enterohepatic circulation of 20:4.},
  author       = {Melin, Tor},
  keyword      = {Lipids,mebran,steroider,Lipider,steroids,membranes,Gastro-enterology,Gastroenterologi},
  language     = {eng},
  pages        = {148},
  publisher    = {ARRAY(0xae6dd60)},
  title        = {Early steps of Eicosanoid precursor absorption and tissue distribution.},
  year         = {1997},
}