VITAMIN-E EXPOSURE MODULATES PROSTAGLANDIN AND THROMBOXANE PRODUCTIONBY AVIAN CELLS OF THE MONONUCLEAR PHAGOCYTIC SYSTEM

The production of Prostaglandin E-2 (PGE(2)) and Thromboxane B-2 (TXB2 ) by turkey blood monocytes and a chicken mononuclear phagocytic cell line MQ-NCSU after exposure to vitamin E (VE) was examined. Turkey emb ryos were exposed in ovo to 0 and 10 international units (IU) of VE; b lood monocytes were collected at 2 weeks of age and cultured. MQ-NCSU macrophage monolayers were exposed to 0, 0.1, 0.25, and 0.5 IU VE. The monocyte/macrophage cultures were exposed to 1 mu g/mL bacterial lipo polysaccharide (LPS). Non-stimulated parallel cultures were maintained as controls. The PGE(2) and TXB2 levels were quantitated in culture s upernatants by a competitive ELISA. Blood monocytes from the 10 IU VE poults produced lower PGE(2) levels as compared with the 0 IU VE contr ols. Upon stimulation with LPS, monocytes from the 10 IU VE group exhi bited levels of PGE(2) that were higher than the 0 IU VE group. Levels of TXB2 were not quantitated in the poult blood monocyte culture supe rnatants. The PGE(2) and TXB2 levels in the supernatant of the VE trea ted MQ-NCSU macrophage cultures were lower than the 0 IU VE controls. Stimulation with LPS resulted in increased PGE(2) and TXB2 production by the VE-exposed macrophages. The results from this study suggest tha t in ovo or in vitro exposure with VE may either upregulate or downreg ulate PGE(2) and TXB2 production by monocytes/macrophages, and that th is production may be dependent upon the exposure to a variety of exter nal stimuli and/or the state of macrophage activation.