Modulation of Arachidonic Acid Metabolism in Rat Peritoneal Macrophages Through Nutritional Means
Magrum, Linda Joyce
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/77446
Description
Title
Modulation of Arachidonic Acid Metabolism in Rat Peritoneal Macrophages Through Nutritional Means
Author(s)
Magrum, Linda Joyce
Issue Date
1983
Department of Study
Food Science
Discipline
Food Science
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Health Sciences, Nutrition
Language
eng
Abstract
Prostaglandins, synthesized from arachidonic acid (20:4(omega)6) in high amounts by the macrophage, are known to regulate a number of activities important to the immune response. In view of the findings that (alpha)-linolenic acid (18:3(omega)3) inhibits the conversion of linoleic acid (18:2(omega)6) to 20:4(omega)6 and that 18:3(omega)3 and both 20:5(omega)3 and 22:6(omega)3, its elongated, desaturated products, inhibit the conversion of 20:4(omega)6 into prostaglandins (PGs), a study of the effect of nutritionally provided (omega)3 fatty acids on the fatty acid composition, PG synthesis, and function of the macrophage was undertaken.
Male Sprague-Dawley weanling rats were fed purified diets containing 10% either corn oil or linseed oil, providing a low (1/32) or high (3.5/1) ratio of 18:3(omega)3 to 18:2(omega)6, respectively. Phospholipid fatty analysis of macrophages from animals fed the diets showed an appreciable increase in the percentage of (omega)3 fatty acids and a decrease in the (omega)6 fatty acids in macrophages from rats fed linseed oil. These changes were associated with a significant decrease in PG synthesis and shown not to involve increased PG degradation.
These results were comparable to those found in macrophages cultured with 20:4(omega)6 or 20:5(omega)3. Differences in phospholipid content of 20:4(omega)6 in macrophages altered in vitro were more striking than those in macrophages altered in vivo; however, in both cases, choline phosphoglyceride exhibited the greatest disparity in 20:4(omega)6 content between the two nutritional treatments. Macrophages altered in vitro exhibited marked differences in their ability to synthesize PGE. Those cultured with 20:5(omega)3 synthesized approximately one-tenth the amount synthesized by macrophages cultured with 20:4(omega)6. Culturing with 20:4(omega)6 or 20:5(omega)3 also overcame dietarily induced changes in PG synthesis.
Activities of the macrophage reported to be influenced by PGs were examined. Phagocytosis was not altered by the increase in dietary 18:3(omega)3. In agreement with previous reports, arginase activity was greater in macrophages showing greater PG synthesis. The synthesis of H(,2)O(,2) as measured by chemiluminescence was greater in macrophages cultured with 20:5(omega)3 than with 20:4(omega)6; however, since indomethacin, an inhibitor of PG synthesis, did not increase chemiluminescence in the 20:4(omega)6-cultured cells, it was concluded this effect was not mediated by PGs.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
