Imaging incorporation of circulating docosahexaenoic acid into the human brain using positron emission tomography
Docosahexaenoic acid (DHA; 22:6n-3) is a critical constituent of the brain, but its metabolism has not been measured in the human brain in vivo. In monkeys, using positron emission tomography (PET), we first showed that intravenously injected [1-11C]DHA mostly entered nonbrain organs, with ∼0.5% ent...
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Published in | Journal of lipid research Vol. 50; no. 7; pp. 1259 - 1268 |
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Main Authors | , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
01.07.2009
American Society for Biochemistry and Molecular Biology Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Docosahexaenoic acid (DHA; 22:6n-3) is a critical constituent of the brain, but its metabolism has not been measured in the human brain in vivo. In monkeys, using positron emission tomography (PET), we first showed that intravenously injected [1-11C]DHA mostly entered nonbrain organs, with ∼0.5% entering the brain. Then, using PET and intravenous [1-11C]DHA in 14 healthy adult humans, we quantitatively imaged regional rates of incorporation (K*) of DHA. We also imaged regional cerebral blood flow (rCBF) using PET and intravenous [15O]water. Values of K* for DHA were higher in gray than white matter regions and correlated significantly with values of rCBF in 12 of 14 subjects despite evidence that rCBF does not directly influence K*. For the entire human brain, the net DHA incorporation rate Jin, the product of K*, and the unesterified plasma DHA concentration equaled 3.8 ± 1.7 mg/day. This net rate is equivalent to the net rate of DHA consumption by brain and, considering the reported amount of DHA in brain, indicates that the half-life of DHA in the human brain approximates 2.5 years. Thus, PET with [1-11C]DHA can be used to quantify regional and global human brain DHA metabolism in relation to health and disease. |
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Bibliography: | This research was supported by the Intramural Research Programs of the National Institutes of Health, National Institute on Alcohol Abuse and Alcoholism, and National Institute on Aging. Published, JLR Papers in Press, December 26, 2008. |
ISSN: | 0022-2275 1539-7262 |
DOI: | 10.1194/jlr.M800530-JLR200 |