抄録
In previous studies, acute exercise might induce inflammatory cytokines from immunological cells, but it was not clear that tumor necrosis factor (TNF) -α in the liver was induced by acute exercise. In this study, we first measured the changes from acute exercise in plasma TNF-α, lipopolysaccharide (LPS), interferon (IFN) -γ and prostaglandin (PG) E2 ; from and investigated the effect of acute exercise on TNF-α expression in the liver. Then we examined the response of TNF-α to PGE2 in isolated Kupffer cells. Female Fischer 344 rats were run on a treadmill at 21 m/min for 60 min on a 15% grade. Although the portal venous plasma endotoxin concentration in the exercised group was higher than that in the resting group, plasma TNF-α was not detected in either group. In addition, plasma IFN-γ, which accelerates TNF-α production, was not detected. TNF-α mRNA expression in the liver didn't change significantly. On the other hand, plasma PGE2, which is an inhibitor of TNF-α production, markedly increased immediately after the exercise. In addition, PGE2 inhibited TNF-α production by LPS-stimulated Kupffer cells in in vitro. These results sug gest that LPS-induced TNF-α expression in rat liver is inhibited by an increase of PGE2 during acute exercise.
