Unique Identifier 15883362
Authors: Jayasooriya AP. Ackland ML. Mathai ML. Sinclair AJ. Weisinger
HS. Weisinger RS. Halver JE. Kitajka K. Puskas LG.
Institution: Howard Florey Institute of Experimental Physiology and
Medicine, University of
Melbourne, Melbourne, Victoria 3052, Australia.
Title: Perinatal omega-3 polyunsaturated fatty acid supply modifies brain
zinc homeostasis during adulthood.
Source: Proceedings of the National Academy of Sciences of the United States
of America. 102(20):7133-8, 2005 May 17.
Abstract
Dietary omega-3 polyunsaturated fatty acid (PUFA) influences the expression
of a number of genes in the brain. Zinc transporter (ZnT) 3 has been
identified as a putative transporter of zinc into synaptic vesicles of
neurons and is found in brain areas such as hippocampus and cortex. Neuronal
zinc is involved in the formation of amyloid plaques, a major characteristic
of Alzheimer's disease.
The present study evaluated the influence of dietary omega-3 PUFA on the
expression of the ZnT3 gene in the brains of adult male Sprague-Dawley rats.
The rats were raised and/or maintained on a control (CON) diet that
contained omega-3 PUFA or a diet deficient (DEF) in omega-3 PUFA. ZnT3 gene
expression was analyzed by using real-time PCR, free zinc in brain tissue
was determined by zinquin staining, and total zinc concentrations in plasma
and cerebrospinal fluid were determined by atomic absorption
spectrophotometry.
Compared with CON-raised animals, DEF-raised animals had increased
expression of ZnT3 in the brain that was associated with an increased level
of free zinc in the hippocampus. In addition, compared with CON-raised
animals, DEF-raised animals had decreased plasma zinc level. No difference
in cerebrospinal fluid zinc level was observed. The results suggest that
overexpression of ZnT3 due to a perinatal omega-3 PUFA deficiency caused
abnormal zinc metabolism in the brain.
Conceivably, the influence of dietary omega-3 PUFA on brain zinc metabolism
could explain the observation made in population studies that the
consumption of fish is associated with a reduced risk of dementia and
Alzheimer's disease.