Effect of inhaled KP-496, a novel dual antagonist of the cysteinyl leukotriene and thromboxane A2 receptors, on a bleomycin-induced pulmonary fibrosis model in mice.

Cysteinyl-leukotrienes (cysLTs) and thromboxane A(2) (TXA(2)) are important mediators in inflammatory lung diseases such as bronchial asthma and idiopathic pulmonary fibrosis (IPF). We examined the effects of inhaled KP-496, a novel dual antagonist of the cysLTs and TXA(2) receptors, on bleomycin-induced IPF in mice. Mice were intravenously injected bleomycin on day 0, and 0.5% of KP-496 was inhaled twice a day (30 min/time) for the entire experimental period. The effects of KP-496 were evaluated by the number of infiltrated cells in bronchoalveolar lavage fluid (BALF), hydroxyl-L-proline content in the lung, and histopathology. Analyses of BALF on days 7 and 21 revealed that inhaled KP-496 significantly decreased total cell numbers, macrophages, neutrophils, and eosinophils on both days. KP-496 significantly decreased hydroxyl-L-proline content in the lung on day 21. Histopathological analyses of lungs on day 21 demonstrated that KP-496 significantly suppressed inflammatory and fibrotic changes. Our results suggested that the suppression of cysLTs and TXA(2) pathways by KP-496 could control airway inflammation and pulmonary fibrosis, and that KP-496 could be a new therapeutic agent for lung diseases with inflammation and fibrogenesis such as IPF and chronic obstructive pulmonary disease.

The effects of inhaled KP-496, a novel dual antagonist for cysteinyl leukotriene receptor and thromboxane A(2) receptor, on allergic asthmatic responses in guinea pigs.

AIMS: The aim of this study was to evaluate the effects of inhaled KP-496, a novel dual antagonist for cysteinyl leukotriene receptor 1 and thromboxane A(2) receptor, on the allergic asthmatic responses in guinea pigs. METHODS: Actively sensitized animals were repeatedly exposed to antigen, and KP-496 (0.01 and 0.1%) was inhaled for 5 min before every antigen exposure. After evaluating the effects of KP-496 on asthmatic responses, such as immediate and late asthmatic response (IAR and LAR) and airway hyperresponsiveness (AHR), histopathological analyses of the lungs of asthmatic animals were made. RESULTS: KP-496 significantly inhibited both antigen-induced LAR and AHR to acetylcholine, and slightly inhibited antigen-induced IAR. Furthermore, histopathological analyses of the lungs of the asthmatic animals demonstrated the following: (1) KP-496 suppressed infiltration of eosinophils around airway smooth muscle, (2) KP-496 suppressed airway epithelial hypertrophy, and (3) KP-496 suppressed increased mucus production in the airway. CONCLUSION: In addition to suppression of LAR and AHR, our findings demonstrated that KP-496 inhibits features of airway inflammation. Since these broad ameliorative effects of KP-496 on asthmatic pathology are thought to result from the inhibition of multiple chemical mediators, KP-496 will be a potent agent in the treatment of bronchial asthma.

[Case of intracerebral hemorrhage due to amphetamine abuse].

We report a case of intracranial hemorrhage due to amphetamine abuse in a young adult. A 34-year-old, confused woman was transferred to our emergency room with right hemiparesis and aphasia. CT at admission demonstrated intracerebral hemorrhage in the left frontal and parietal lobes, associated with subarachnoid hemorrhage. MRA shortly after admission revealed no intracerebral vascular anomaly. Cerebral angiography following admission showed irregularity of the vessel wall in the left anterior and middle cerebral arteries. Later, a toxicology screen test for urine was found to be positive for amphetamines and metamphetamines. These findings suggested that cerebral vasculitis and hypertensive surge induced by amphetamines caused intracranial and subarachnoid hemorrhage. Amphetamine abuse should always be considered as a cause of intracranial hemorrhage in young adults.

Effects of KP-496, a novel dual antagonist for cysteinyl leukotriene receptor 1 and thromboxane A2 receptor, on Sephadex-induced airway inflammation in rats.

Bronchial asthma is characterized by chronic airway inflammation. Eosinophils are involved in airway inflammation and play crucial roles in asthma. There is accumulating evidence to suggest contributions of cysteinyl leukotrienes (cysLTs) and thromboxane (TX) A(2) to the recruitment of eosinophils into lung in asthmatics. KP-496 is a novel dual antagonist for CysLT receptor type 1 and TXA(2) receptors. The aim of this study was to evaluate the anti-inflammatory effects of KP-496 on Sephadex-induced airway inflammation. Sephadex suspension was intratracheally injected into rats. Amounts of regulated on activation, normal T cell expressed and secreted (RANTES) and eotaxin, and numbers of infiltrating cells in bronchoalveolar lavage fluid were measured 24 and 48 h after Sephadex injection, respectively. KP-496 (30, 100 microg/head) was intratracheally administered to rats 1 h before and 7 h after Sephadex injection. KP-496 and prednisolone (10 mg/kg, per os) exhibited significant inhibitory effects on infiltration of total cells and eosinophils into lung. Production of RANTES was significantly inhibited by KP-496 and prednisolone. Production of eotaxin was significantly inhibited by prednisolone. KP-496 also inhibited the production of eotaxin, though this effect was not significant. These results demonstrate that KP-496 exhibited the anti-inflammatory effects by inhibiting infiltration of inflammatory cells and productions of RANTES and eotaxin.