Docosahexaenoic acid (DHA) content of membranes determines molecular activity of the sodium pump: implications for disease states and metabolism
The omega-3 polyunsaturate, docosahexaenoic acid (DHA), plays a number of biologically important roles, particularly in the nervous system, where it is found in very high concentrations in cell membranes. In infants DHA is required for the growth and functional development of the brain, with a deficiency resulting in a variety of learning and cognitive disorders. During adulthood DHA maintains normal brain function and recent evidence suggests that reduced DHA intake in adults is linked with a number of neurological disorders including schizophrenia and depression. Here we report a high positive correlation between the molecular activity (ATP min−1) of individual Na+K+ATPase units and the content of DHA in the surrounding membrane bilayer. This represents a fundamental relationship underlying metabolic activity, but may also represent a link between reduced levels of DHA and neurological dysfunction, as up to 60% of energy consumption in the brain is linked to the Na+K+ATPase enzyme.
We thank Parisa Abolhasan for technical assistance. This work was supported by a grant from the Australian Research Council. All experimental procedures were performed in conformity with the National Health and Medical Research Council Guidelines for animal research in Australia and were approved by the Animal Experimentation Ethics committee of the University of Wollongong.
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