YM-393059 is a novel phosphodiesterase (PDE) 7A and PDE4 dual inhibitor that inhibits both Th1 [interleukin (IL)-2 and interferon-gamma] and Th2 (IL-4) cytokines in vitro [Yamamoto, S., Sugahara, S., Naito, R., Ichikawa, A., Ikeda, K., Yamada, T., Shimizu, Y., 2006. The effects of a novel phosphodiesterase 7A and -4 dual inhibitor, YM-393059, on T-cell-related cytokine production in vitro and in vivo. Eur. J. Pharmacol. 541, 106-114]. To characterize the pharmacological profile of YM-393059, its effects on several acute and chronic inflammation models were examined. In acute inflammation models, YM-393059 significantly suppressed the delayed-type hypersensitivity reaction to sheep red blood cells in mice with an ED(50) value of 17.1 mg/kg. YM-393059 failed to suppress paw edema in the carrageenin-induced edema model in rats. These pharmacological effects were similar to those of cyclosporine, a typical T-cell immunosuppressant. However, YM-393059, but not cyclosporine, significantly inhibited zymosan-induced neutrophil accumulation in mice with an ED(50) value of 25.7 mg/kg. In mouse toluene-2,4-diisocyanate-induced contact dermatitis, a chronic inflammation model, YM-393059 and cyclosporine significantly suppressed ear edema at doses of 30 and 20 mg/kg, respectively. In this model, YM-393059 also tended to reduce the serum immunoglobulin E antibody level, whereas cyclosporine dramatically potentiated it. These results suggest that YM-393059 inhibits both Th1- and Th2-cell-dependent reactions and also the function of neutrophils.