De novo lipogenesis in adipose tissue of lean and obese women: application of deuterated water and isotope ratio mass spectrometry.
OBJECTIVE
To evaluate the feasibility of using deuterated water and isotope ratio mass spectrometry to measure de novo fatty acid synthesis in adipose tissue, and to compare this parameter in obese and lean women.


METHODS
Six lean and six obese premenopausal Caucasian women in the main study and three obese Pima Indians in a pilot study.


METHODS
Deuterated water was administered orally twice daily for 14 days to create stable deuterium enrichment in body water, during which series of blood samples were collected to measure body water deuterium enrichment and deuterium incorporation into plasma total Triacylglycerol (TG) fatty acids and total cholesterol. Subcutaneous fat at different sites were sampled at the beginning and the end of deuterium administration to measure deuterium incorporation into TG fatty acids.


RESULTS
Fractional de novo synthesis rate of TG fatty acids in adipose tissue was 0. 014+/-0.005 and 0.014+/-0.007% in lean and obese Caucasian women, corresponding to 2+/-0.7 and 5.6+/-3.2 g (P=0.3) of fatty acids synthesized daily, respectively. Plasma TG fatty acids and cholesterol synthesis rates were comparable to those reported previously. A pilot study showed that de novo lipid synthesis in adipose tissue of obese Pima Indians was also quantitatively minor.


CONCLUSIONS
Human adipose tissue, like the liver, does not make a major contribution to whole body lipogenesis under eucaloric conditions. A combination of deuterated water and isotope ratio mass spectrometry is a useful research tool for studying accumulation of de novo synthesized lipids in human adipose tissue.
Department of Medicine, University of Chicago, Chicago, IL 60637, USA.
Z K
ZK
Guo
L K
LK
Cella
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C
Baum
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E
Ravussin
D A
DA
Schoeller
D017667:Adipocytes / Q000502:physiology; D000273:Adipose Tissue / Q000502:physiology*; D000328:Adult; D001130:Arizona; D001823:Body Composition / Q000502:physiology; D002784:Cholesterol / Q000097:blood / Q000737:chemistry; D017666:Deuterium Oxide / Q000008:administration & dosage*; D005227:Fatty Acids / Q000096:biosynthesis* / Q000097:blood / Q000737:chemistry; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007198:Indians, North American; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D009765:Obesity / Q000208:ethnology / Q000378:metabolism*; D010865:Pilot Projects
D005227:Fatty Acids; D002784:Cholesterol; D017666:Deuterium Oxide