Effects of Polyunsaturated Fatty Acids on Glial Cell Activation. A Study Using Primary Cultures

Abstract

The aim of this study was to examine the effects of essential fatty acids (gammalinolenic acid [18:3 n-6; GLA] and alpha-linolenic acid [18:3 n-3; Lin]) on the activation of glial cells, using lipopolysaccharides as the activating agent. Primary cultures of mixed glial cells from rat brain were used as the model. The morphological activation of microglia was the most significant response to the exposure. This activation was followed by an increase in 5’-nucleotidase (5’-NT) activity. The 5’-NT activity was increased by GLA or Lin alone to 250–350% of the control value and further increased by co-incubation with lipoteichoic acid (a lipopolysaccharide) to 500–600% of the control value. The lipopolysaccharide-induced activation of glial cells was also followed by an augmented release of prostaglandin E2. GLA increased the release of prostaglandin E2 in a dose-dependent manner, whereas Lin had no effect on its release. The results show that this model system is useful for studies on factors affecting the activation of glial cells. GLA and Lin did not reverse glial activation induced by lipopolysaccharides under these experimental conditions.