The effects of
NZ-107 on some airway
inflammation models and the generation of
superoxide anion (O2-) were studied in guinea-pigs. Airway
inflammation was caused by intra-tracheal injection of murine recombinant
interleukin-5 (mrIL-5, 15 micrograms/animal), inhalation of
platelet-activating factor (PAF, 0.003%) and intra-tracheal injection of
leukotriene B4 (
LTB4, 10 micrograms/animal).
NZ-107 (4-bromo-5-(3-ethoxy-4-methoxybenzylamino)-3(2H)-pyridazinone) at a dose of 50 mg kg-1, intraperitoneally reduced mrIL-5- and PAF-induced
eosinophilia. This compound at a dose of 25 and 50 mg kg-1 also suppressed LTB4-induced
eosinophilia and neutrophilia in bronchoalveolar lavage fluid (BALF). On the other hand,
prednisolone at a dose of 20 mg kg-1, i.p., prevented the increased number of macrophages, eosinophils and neutrophils induced by mrIL-5, the increased number of eosinophils induced by PAF and the increased number of eosinophils and neutrophils induced by
LTB4 in BALF. Furthermore, both drugs reduced mrIL-5- or PAF-induced increase in the number of airway epithelial cells in BALF. The generation of O2- was measured by the method of
cytochrome C reduction.
NZ-107 (10-100 micrograms mL-1) attenuated PAF- and FMLP-induced O2- production from macrophages and reduced PAF-induced O2- generation by eosinophils but had no effect on that from neutrophils. These results indicate that
NZ-107 prevents the increased number of pulmonary eosinophils and airway epithelial cells and the activation of macrophages and eosinophils, suggesting that
NZ-107 may be useful as a remedy for airway inflammatory diseases such as
bronchial asthma.