Early steps of Eicosanoid precursor absorption and tissue distribution.
(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:
https://lup.lub.lu.se/record/29302
- author
- Melin, Tor LU
- supervisor
- opponent
-
- Prof Vessby, B., Uppsala University
- organization
- publishing date
- 1997
- 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 10:15:00
- 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
- 2016-04-04 12:04:46
- date last changed
- 2018-11-21 21:08:52
@phdthesis{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}},
keywords = {{Lipids; mebran; steroider; Lipider; steroids; membranes; Gastro-enterology; Gastroenterologi}},
language = {{eng}},
publisher = {{Gastroenterology Division, Dept Internal Medicine, University Hospital, S-221-85 Lund, Sweden}},
school = {{Lund University}},
title = {{Early steps of Eicosanoid precursor absorption and tissue distribution.}},
year = {{1997}},
}