Takeshi Nabe, Makoto Miura, Toshihisa Kamiki and Shigekatsu Kohno*
Department of Pharmacology, Kyoto Pharmaceutical University, 5 Nakauchi,
Misasagi, Yamashina, Kyoto 607-8414, Japan
*ĘTo whom correspondence should be addressed.
Abstract: To investigate the cellular sources of arachidonate
metabolites during asthma, in vitro productions of thromboxane (TX)ĘB2,
prostaglandin (PG)ĘD2, leukotriene (LT)ĘB4 and cysteinyl
(Cys) LTs from guinea pig eosinophils and macrophages simultaneously stimulated
with the Ca ionophore A23187 were investigated. Eosinophils produced high
levels of LTB4 and TXB2 and relatively low levels
of CysLTs and PGD2. Although macrophages released abundant TXB2
and a little PGD2, 5-lipoxygenase metabolites were below detectable
levels. In conclusion, eosinophils produced both cyclooxygenase and 5-lipoxygenase
metabolites, while arachidonate metabolism in the macrophages was almost
completely inclined toward the cyclooxygenase pathway.
Keywords: Eosinophil, Macrophage, Arachidonic acid