No abstract

Azosemide, 5, 10, 20, and 30 mg/kg, was administered both intravenously and orally to determine the pharmacokinetics and pharmacodynamics of azosemide in rats (n = 7-12). The absorption of azosemide from various segments of GI tract and the reasons for the appearance of multiple peaks in plasma concentrations of azosemide after oral administration were also investigated. After intravenous (iv) dose, the pharmacokinetic parameters of azosemide such as t1/2. MRT, VSS, CL, CLR, and CLNR were found to be dose-dependent in the dose ranges studied. The percentages of the iv dose excreted in 8-hr urine as azosemide, MI (a metabolite of azosemide), glucuronide of azosemide, and glucuronide of MI-expressed in terms of azosemide-were also dose-dependent in the dose ranges studied. The data above suggest saturable metabolism of azosemide in rats. The measurements taken after the iv administrations such as the 8 hr urine output, the total amount of sodium and chloride excreted in 8-hr urine per 100 g body weight, and diuretic, natriuretic, kaluretic, and chloruretic efficiencies were also shown to be dose-dependent. However, the total amount of potassium excreted in 8-hr urine per 100 g body weight was dose-independent. Similar dose-dependency was also observed following oral administration. Azosemide was absorbed from all regions of GI tract studied and approximately 93.5, 79.1, 86.1, and 71.5% of the doses (5, 10, 20, and 30 mg/kg, respectively) were absorbed between 1 and 24 hr after oral administration. The appearance of multiple peaks after oral administration is suspected to be due mainly to the gastric emptying pattern. The percentages of azosemide absorbed from the GI tract as unchanged azosemide for up to 24 hr after oral doses of 5, 10, 20, and 30 mg/kg were significantly different with doses (decreased with increasing doses), suggesting that the problem of azosemide precipitating in acidic gastric juices or dissolution may have at least partially influenced the absorption of azosemide after oral administration.

We report that S100 proteins were reduced in patients with chronic rhinosinusitis (CRS). S100A8/9, which is important in epithelial barrier function, was particularly decreased in elderly patients with CRS. Epithelial expression of S100A8/9 is partly regulated by the IL-6 trans-signaling pathway. The goal of this study was to investigate whether or not age-related reduction of S100A8/9 in CRS is associated with blunting of IL-6 trans-signaling. The levels of IL-6, soluble IL-6 receptor (sIL-6R), soluble gp130 (sgp130), and S100A8/9 from control subjects (n = 10), and patients with CRS without nasal polyps (n = 13) and those with CRS with nasal polyps (CRSwNP) (n = 14), were measured by ELISA. Age-related differences in the level of each protein were investigated. Normal human bronchial epithelial cells were cultured in air-liquid interface and stimulated with IL-6/ sIL-6R and tumor necrosis factor (TNF)-a with or without the addition of sgp130, a natural inhibitor of IL-6 trans-signaling. There was a significant age-related decline in S100A8/9 and an increase in sgp130 in nasal tissue samples from patients with CRSwNP, although there was no age-related difference in IL-6/sIL-6R production.Additionally, expression of the S100A8/9 gene and protein was increased significantly by IL-6/sIL-6R plus TNF-a in normal human bronchial epithelial cells. This increase was blocked by sgp130. These results suggest that increased sgp130 in older patients may inhibit IL-6 trans-signaling, impair barrier function, and decrease S1008/9 production in elderly patients with CRSwNP. Restoration of barrier function by targeting sgp130 may be a novel treatment strategy.

We previously reported that plasminogen activator inhibitor (PAI)-1 deficiency prevents collagen deposition in the airways of ovalbumin (OVA)-challenged mice. In this study, we explored the therapeutic utility of blocking PAI-1 in preventing airway remodeling, using a specific PAI-1 inhibitor, tiplaxtinin. C57BL/6J mice were immunized with intraperitoneal injections of OVA on Days 0, 3, and 6. Starting on Day 11, mice were challenged with phosphate-buffered saline or OVA by nebulization three times per week for 4 weeks. Tiplaxtinin was mixed with chow and administered orally from 1 day before the phosphate-buffered saline or OVA challenge. Lung tissues were harvested after challenge and characterized histologically for infiltrating inflammatory cells, mucus-secreting goblet cells, and collagen deposition. Airway hyperresponsiveness was measured using whole-body plethysmography. Tiplaxtinin treatment significantly decreased levels of PAI-1 activity in bronchoalveolar lavage fluids, which indicates successful blockage of PAI-1 activity in the airways. The number of infiltrated inflammatory cells was reduced by tiplaxtinin treatment in the lungs of the OVA-challenged mice. Furthermore, oral administration of tiplaxtinin significantly attenuated the degree of goblet cell hyperplasia and collagen deposition in the airways of the OVA-challenged mice, and methacholine-induced airway hyperresponsiveness was effectively reduced by tiplaxtinin in these animals. This study supports our previous findings that PAI-1 promotes airway remodeling in a murine model of chronic asthma, and suggests that PAI-1 may be a novel target of treatment of airway remodeling in asthma.Keywords: asthma; airway remodeling; collagen deposition; plasminogen activator inhibitor-1; tiplaxtinin Allergic asthma is now the most common chronic disease of children, and one of the most common respiratory diseases in adults. The hallmark of asthma is chronic airway inflammation with multiple pulmonary pathologies, including airway hyperresponsiveness (AHR), eosinophilic infiltration, mucus hypersecretion, and subepithelial fibrosis (1, 2).Plasminogen activator inhibitor (PAI)-1 is a member of the serine protease inhibitor gene family, and the major physiologic inhibitor of the serine proteases, urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA). Because uPA and tPA play important roles in damping tissue matrix deposition, high levels of PAI-1 lead to excess extracellular matrix formation (3). Under normal conditions, PAI-1 is present in plasma and tissues at low concentrations. Elevated levels of PAI-1 are often observed in a variety of pathologic conditions and clinical settings, such as infection, stroke, myocardial infarction, diabetes, obesity, sepsis, and cancers (4, 5). We previously reported that the levels of PAI-1 were elevated in the airways of a murine model of chronic asthma, and that PAI-1 deficiency was associated with reduced airway fibrosis in these mice (6). We also demonstrated that PAI-1 expression wa...

Stability of azosemide after incubation in various pH solutions, human plasma, human gastric juice, and rat liver homogenates, metabolism of azosemide after incubation in 9000 g supernatant fraction of various rat tissue homogenates in the presence of NADPH, tissue distribution of azosemide and M1 after intravenous (i.v.) administration of azosemide, 20 mg kg-1, to rats, and blood partition of azosemide between plasma and blood cells from rabbit blood were studied. Azosemide seemed to be stable for up to 48 h incubation in various pH solutions ranging from two to 13 at an azosemide concentration of 10 micrograms mL-1; more than 93.4% of azosemide was recovered, and a metabolite of azosemide, M1, was not detected. However, the drug was unstable in pH1 solution: 75.8% of azosemide was recovered and 2.16 micrograms mL-1 of M1 (expressed in terms of azosemide) was formed after 48 h incubation in pH 1 solution at an azosemide concentration of 10 micrograms mL-1. Azosemide was stable in both human plasma and rat liver homogenates for up to 24 h incubation at an azosemide concentration of 1 microgram mL-1, and in human gastric juice for up to 4 h incubation at an azosemide concentration of 10 micrograms mL-1. However, all rat tissues studied had metabolic activity for azosemide in the presence of NADPH, with heart having a considerable metabolic activity: approximately 22% of azosemide disappeared and 9.32 micrograms of M1 was formed per gram of heart (expressed in terms of azosemide) after 30 min incubation of 50 micrograms of azosemide in 9000 g supernatant fraction of heart homogenates. The tissue to plasma ratios of azosemide (T/P) were greater than unity only in the liver (1.26) and kidney (1.74); however, M1 showed high affinity for all tissues studied except the brain and spleen when each tissue was collected at 30 min after i.v. administration of azosemide to rats. The equilibrium plasma to blood cell concentration ratios of azosemide were independent of azosemide blood concentrations: the values were 2.78-4.25 at azosemide blood concentrations of 1, 10, and 20 micrograms mL-1 in three rabbits. There was negligible 'blood storage effect' of azosemide, especially at low blood concentrations of azosemide, such as 1 and 10 micrograms mL-1.