Vitamin E Exposure Modulates Prostaglandin and Thromboxane Production by Avian Cells of the Mononuclear Phagocytic System

Abstract

The production of Prostaglandin E2 (PGE2) and Thromboxane B2 (TXB2) by turkey blood monocytes and a chicken mononuclear phagocytic cell line MQ-NCSU after exposure to vitamin E (VE) was examined. Turkey embryos were exposed in ovo to 0 and 10 international units (IU) of VE; blood 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 μg/mL bacterial lipopolysaccharide (LPS). Non-stimulated parallel cultures were maintained as controls. The PGE2 and TXB2 levels were quantitated in culture supernatants by a competitive ELISA. Blood monocytes from the 10 IU VE poults produced lower PGE2 levels as compared with the 0 IU VE controls. Upon stimulation with LPS, monocytes from the 10 IU VE group exhibited levels of PGE2 that were higher than the 0 IU VE group. Levels of TXB2 were not quantitated in the poult blood monocyte culture supernatants. The PGE2 and TXB2 levels in the supernatant of the VE treated MQ-NCSU macrophage cultures were lower than the 0 IU VE controls. Stimulation with LPS resulted in increased PGE2 and TXB2 production by the VE-exposed macrophages. The results from this study suggest that in ovo or in vitro exposure with VE may either upregulate or downregulate PGE2 and TXB2 production by monocytes/macrophages, and that this production may be dependent upon the exposure to a variety of external stimuli and/or the state of macrophage activation.