Selective inhibition of leukotriene B4 biosynthesis in rat pulmonary alveolar macrophages by dietary selenium deficiency

Weanling male Fisher 344 rats were maintained on low selenium basal and Se-supplemented diets for 38 weeks. A several fold reduction in the glutathione peroxidase activity of the lung and liver tissues in rats maintained on low Se basal diet established their Se-deficient status. Analysis of the supernatants from resting pulmonary alveolar macrophage suspensions showed negligible extracellular release of PGE2, TXB2 and LTB4 in both diet groups. A challenge with opsonized zymosan particles increased the release of the same three arachidonic acid metabolites by several fold in both diet groups. The differences between the two diet groups with respect to the secretion of the products of the cyclooxygenase pathway, PGE2 and TXB2 were negligible. By contrast, a significant reduction in the extracellular release of LTB4 was observed in cells from animals on low selenium basal diet. These results suggest a selective inhibition of LTB4 biosynthesis in pulmonary alveolar macrophages by dietary deficiency of selenium.