DIETARY N-3 FATTY ACIDS: TRANSPORT AND UPTAKE INTO BRAIN

  • Anderson, Gregory, (PI)

Project: Research project

Description

The brain is roughly fifty percent lipid, with polyunsaturates making up
35% of the total fatty acids. The brain and retina, and in particular the
synaptic membranes and rod outer segments, are especially rich in the n-3
family of polyunsaturated fatty s. Nutritional studies in animals have
identified numerous abnormalities when n-3 fatty acids are deficient in the
diet. These include reduced visual acuity, impaired learning, altered
behavior, and effects on sleep. The process by which these critical
polyunsaturated fatty acids reach the brain is unclear. The long-term
objective of this research is to characterize the transport and uptake of
lipids, particularly n-3 fatty acids, into the brain, and to examine the
nutritional qualities of n-3 fatty acids and their role in the brain. The
n-3 fatty acids have also recently become the focus of research as regards
their possible prevention of coronary heart disease. The transport and uptake of lipids by the brain will be studied first in
the two-week old rat, whose brain is rapidly accumulating polyunsaturated
fatty acids. Intravenous injection of radiolabeled saturated, n-6, and n-3
fatty acids, contained in phospholipids, chylomicrons, and as free fatty
acids, will test whether there is a preferred chemical form for
"brain-destined" fatty acids. Previous experiments showing a preferential
uptake by the brain of n-3 fatty acids will expanded by examining the
developmental course of uptake and the effect of diet. In addition, the
possible role of the liver will be examined by functionally hepatectomizing
some of the animals. The nutritional qualities of individual n-3 fatty acids and the role of
22:6n-3 in the brain will be studied in n-3 fatty acid deficient chicks.
Chicks are an especially useful model because of the speed with which the
fatty acid composition of eggs (and thus the resulting chick tissues,
including the brain) can be manipulated through the feeding of an n-3 fatty
acid-free diet to laying hens. 18:3n-3, 20:5n-3, and 22:6n-3 will be fed to
these virtually n-3 fatty acid-free chicks, and the relative effects on
brain, retina, and serum fatty acid composition will be studied. Also, the
reversibility of 22:6n-3 feeding will be examined in these tissues. The
role of n-3 fatty acids in the brain will be probed by determining the
effects of the deficiency on brain phospholipid molecular species
composition, brain enzyme activities (ethanolaminephosphotransferase,
phosphatidylethanolamine methyltransferase, 5'-nucleotidase), growth, and
reproduction.
StatusFinished
Effective start/end date7/1/896/30/95

Funding

  • National Institutes of Health: $96,639.00
  • National Institutes of Health
  • National Institutes of Health: $116,415.00
  • National Institutes of Health
  • National Institutes of Health

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Omega-3 Fatty Acids
Brain
Fatty Acids
Ethanolaminephosphotransferase
Acids
Retina
Phospholipids
Phosphatidylethanolamine N-Methyltransferase
Diet
Rod Cell Outer Segment
Lipids
Chylomicrons
5'-Nucleotidase
Personal Autonomy
Nutritive Value
Research
Intravenous Injections
Eggs
Visual Acuity
Coronary Disease

ASJC

  • Medicine(all)