Composition and structure of triacylglycerols in brown adipose tissue of rats fed fish oil |
| |
Authors: | Thierry Raclot René Groscolas Claude Leray |
| |
Affiliation: | (1) Centre d'Ecologie et Physiologie Energétiques, CNRS, 23 rue Becquerel, 67087 Strasbourg, France |
| |
Abstract: | This study examines the incorporation of highly unsaturated n−3 fatty acids (HUFA) into triacylglycerols (TAG) of brown adipose
tissue (BAT), and their effect on the positional distribution of saturated (SFA) and of unsaturated (UFA) 16- or 18-carbon
fatty acids. To this end, rats were fed a fish oil diet for up to four weeks. The stereospecific analysis of TAG was based
on generation ofsn-1,2- andsn-2,3-acylglycerols by Grignard degradation, followed by synthesis of phosphatidic acid and specific hydrolysis with phospholipase
A2. From the end of the first week of fish oil feeding, a steady-state in the fatty acid composition of TAG in BAT was reached.
HUFA concentration increased 30-fold, mainly at the expense of n−9 UFA and of SFA. The amount of SFA decreased selectively
at position 3, where these fatty acids were progressively replaced by n−3 HUFA. By contrast, the amount of UFA decreased at
all positions, and their positional distribution was not affected. About 60% of HUFA was incorporated at position 3. Nearly
twice as much 22∶6n−3 was incorporated into TAG than had been previously observed in white adipose tissue (WAT) Leray, C.,
Raclot, T., and Groscolas, R. (1993)Lipids 28, 279–284]. At the steady-state, the distribution of HUFA was characterized by high proportions of 22∶6n−3 and 20∶5n−3 in
position 3. Moreover, in each position of TAG, a steady level was reached rapidly (within 1 wk). It is concluded that, during
fish-oil feeding, fatty acids in TAG of BAT show characteristic time-course changes that lead to a characteristic composition
and a tissue-specific positional distribution. This suggests that adipose tissue has its own specificity in controlling the
build-up of TAG stores, which is likely to be regulated by the specificity of acylating enzymes as well as molecular rearrangements. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|