J. Lipid Res.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

A more recent version of this article appeared on August 1, 2006

Papers In Press, published online ahead of print May 10, 2006
J. Lipid Res., doi:10.1194/jlr.M600030-JLR200
This Article
Right arrow Full Text (Accepted Manuscript)
Right arrow All Versions of this Article:
M600030-JLR200v1
47/8/1812    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Igarashi, M.
Right arrow Articles by DeMar ., J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Igarashi, M.
Right arrow Articles by DeMar ., J. C., Jr
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Submitted on January 18, 2006
Revised on April 4, 2006
Accepted on May 9, 2006

Rates of alpha -linolenic acid incorporation into stable lipids and conversion to docosahexaenoic acid in liver of unanesthetized rats fed a high docosahexaenoate-containing diet

Miki Igarashi, Kaizong Ma, Lisa Chang, Jane M. Bell, Stanley I. Rapoport, and James C. DeMar . Jr

BPMS/NIA/NIH, Bethesda, MD 20892

Corresponding Author: mikii{at}mail.nih.gov

We quantified rates of incorporation of a-linolenic acid (a-LNA, 18:3n-3) into “stable” lipids (e.g. triacylglycerol, phospholipid, cholesteryl ester), as well as the rate of conversion of a-LNA to docosahexaenoic acid (DHA, 22:6n-3), in the liver of unanesthetized male rats on a diet whose fatty acid content contained 2.3% DHA (of total fatty acid, wt/wt). We infused [1-14C]a-LNA intravenously in these rats to produce a steady-state plasma radioactivity, collected arterial plasma, microwaved and removed the liver at 5 min, then measured specific activities of plasma and liver lipids. At 5 min, 72.7% of liver radioactivity (excluding unesterified fatty acid radioactivity) was in stable lipids, whereas the remainder was in the aqueous compartment (largely products of beta-oxidation). Taking into account the steady-state specific activity of the liver a-LNA-CoA precursor pool, in the form of the measured dilution coefficient, we used our in vivo model to calculate incorporation rates of unesterified a-LNA into liver triacylglycerol, phospholipid and cholesteryl ester (2401, 749 and 9.6 nmol/s/g x 10-4, respectively [sum = 3160 nmol/s/g x 10-4]), and a lower bound for the rate of synthesis of DHA from a-LNA by the liver, 15.8 nmol/s/g x 10-4 (0.5% of net incorporation rate). Turnover rates of a-LNA in liver triacylglycerol, phospholipid and cholesteryl ester equaled 3.2, 8.7 and 2.9 %/min, respectively, corresponding to half-lives of 8-24 min. Thus, in animals fed a high DHA-containing diet, rates of beta-oxidation and esterification of a-LNA into stable liver lipids are high, compared with a low rate of a-LNA conversion to DHA. Comparison with published brain data suggests that the conversion rate is insufficient to supply significant DHA to brain.High a-LNA incorporation and turnover rates likely reflect a high rate of secretion by liver of stable lipids packaged within very low density lipoproteins.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 J. Lipid Res.Home page
J. C. DeMar Jr., C. DiMartino, A. W. Baca, W. Lefkowitz, and N. Salem Jr.
Effect of dietary docosahexaenoic acid on biosynthesis of docosahexaenoic acid from alpha-linolenic acid in young rats
J. Lipid Res., September 1, 2008; 49(9): 1963 - 1980.
[Abstract] [Full Text] [PDF]

Home page
 J. Lipid Res.Home page
M. Igarashi, K. Ma, L. Chang, J. M. Bell, and S. I. Rapoport
Rat heart cannot synthesize docosahexaenoic acid from circulating {alpha}-linolenic acid because it lacks elongase-2
J. Lipid Res., August 1, 2008; 49(8): 1735 - 1745.
[Abstract] [Full Text] [PDF]

Home page
 J. Lipid Res.Home page
M. Igarashi, K. Ma, L. Chang, J. M. Bell, and S. I. Rapoport
Dietary n-3 PUFA deprivation for 15 weeks upregulates elongase and desaturase expression in rat liver but not brain
J. Lipid Res., November 1, 2007; 48(11): 2463 - 2470.
[Abstract] [Full Text] [PDF]

Home page
 J. Nutr.Home page
B. Levant, M. K. Ozias, and S. E. Carlson
Diet (n-3) Polyunsaturated Fatty Acid Content and Parity Affect Liver and Erythrocyte Phospholipid Fatty Acid Composition in Female Rats
J. Nutr., November 1, 2007; 137(11): 2425 - 2430.
[Abstract] [Full Text] [PDF]

Home page
 J. Lipid Res.Home page
M. Igarashi, J. C. DeMar Jr., K. Ma, L. Chang, J. M. Bell, and S. I. Rapoport
Docosahexaenoic acid synthesis from {alpha}-linolenic acid by rat brain is unaffected by dietary n-3 PUFA deprivationboxs
J. Lipid Res., May 1, 2007; 48(5): 1150 - 1158.
[Abstract] [Full Text] [PDF]

Home page
 J. Lipid Res.Home page
M. Igarashi, J. C. DeMar Jr., K. Ma, L. Chang, J. M. Bell, and S. I. Rapoport
Upregulated liver conversion of {alpha}-linolenic acid to docosahexaenoic acid in rats on a 15 week n-3 PUFA-deficient diet
J. Lipid Res., January 1, 2007; 48(1): 152 - 164.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
 All ASBMB Journals   Journal of Biological Chemistry 
 Molecular and Cellular Proteomics   ASBMB Today 
Copyright © 2006 by the American Society for Biochemistry and Molecular Biology.