Metabolism in humans ofcis-12,rans-15-octadecadienoic acid relative to palmitic,stearic, oleic and linoleic acids |
| |
Authors: | E A Emken W K Rohwedder R O Adlof H Rakoff R M Gulley |
| |
Affiliation: | (1) Northern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 1815 N. University St., 61604 Peoria, Illinois;(2) St. Francis Medical Center, Peoria, Illinois |
| |
Abstract: | Mixtures of triglycerides containing deuterium-labeled hexadecanoic acid (16∶0), octadecanoic acid (18∶0),cis-9-octadecenoic acid (9c–18∶1),cis-9,cis-12-octadecadienoic acid (9c, 12c–18∶2) andcis-12,trans-15-octadecadienoic acid (12c,15t–18∶2) were fed to two young-adult males. Plasma lipid classes were isolated from samples
collected periodically over 48 hr. Incorporation and turnover of the deuterium-labeled fats in plasma lipids were followed
by gas chromatography-mass spectrometry (GC-MS) analysis of the methyl ester derivatives. Absorption of the deuterated fats
was followed by GC-MS analysis of chylomicron triglycerides isolated by ultracentrifugation.
Results were the following: (i) endogenous fat contributed about 40% of the total fat incorporated into chylomicron triglycerides;
(ii) elongation, desaturation and chain-shortened products from the deuterated fats were not detected; (iii) the polyunsaturated
isomer 12c,15t–18∶2 was metabolically more similar to saturated and 9c–18∶1 fatty acids than to 9c,12c–18∶2 (iv) relative
incorporation of 9c,12c–18∶2 into phospholipids did not increase proportionally with an increase of 9c,12c–18∶2 in the mixture
of deuterated fats fed; (v) absorption of 16∶0, 18∶0, 9c–18∶1, 9c,12c–18∶2 and 12c,15t–18∶2 were similar; and (vi) data for
the 1- and 2-acyl positions of phosphatidylcholine and for cholesteryl ester fractions reflected the known high specificity
of phosphatidylcholine acyltransferase and lecithin:cholesteryl acyltransferase for 9c,12c–18∶2.
These results illustrate that incorporation of dietary fatty acids into human plasma lipid classes is selectively controlled
and that incorporation of dietary 9c,12c–18∶2 is limited. These results suggest that nutritional benefits of diets high in
9c,12c–18∶2 may be of little value to normal subjects and that the 12c,15t–18∶2 isomer in hydrogenated fat is not a nutritional
liability at the present dietary level. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|