l-663536 and montelukast

Hepatic ischemia-reperfusion injury (I/R) may occur in transplantation, trauma, and elective hepatic resections. Leukotrienes have been shown to play a major role in hepatic I/R injury. Five-lipoxygenase enzyme is an important enzyme in the production of leukotrienes from arachidonic acid. MK-886 is an inhibitor of 5-lipoxygenase, and montelukast is a cysteinyl leukotriene receptor antagonist. The aim of this study was to investigate whether MK-886 and montelukast are effective in preventing hepatic I/R injury.. Rats were divided into five groups consisting of seven rats in each: (1) Control I/R, (2) Control-montelukast, (3) Control-MK-886, (4) I/R+montelukast, and (5) I/R+MK-886. Thirty min of total hepatic vascular occlusion and then 60 min reperfusion were performed to animals in groups 1, 4, and 5. In groups 2 and 4, montelukast, and in groups 3 and 5, MK-886 was applied intraperitoneally before and during the surgical procedures.. Apoptosis in the liver and intestine decreased significantly in the I/R+montelukast and I/R+MK-886 groups compared with the I/R group. Tissue malondialdehyde levels and glutathione consumptions also decreased significantly in the I/R+montelukast and I/R+MK-886 groups compared with the I/R group. The difference in serum alanine aminotransferase and aspartate aminotransferase levels between the groups did not reach significance.. Montelukast and MK-886 were found to be effective in prevention of liver and intestine injury by reducing apoptosis and oxidative stress in a hepatic I/R model. Anti-inflammatory properties and inhibition of lipid peroxidation by montelukast and MK-886 could be protective for these organs in I/R injury.

Topics: Acetates; Animals; Cyclopropanes; Disease Models, Animal; Indoles; Leukotriene Antagonists; Lipoxygenase Inhibitors; Liver Diseases; Male; Quinolines; Rats; Rats, Wistar; Reperfusion Injury; Sulfides

Cysteinyl-leukotriene-1 receptor antagonists are important tools in the therapy of asthma. Although many studies have been performed concerning their effects on airway smooth muscle tone, there are no basic data on their effects on airway secretions. Therefore, we assessed the effects of zafirlukast and montelukast on rat tracheal secretion by quantification of secreted 35S04 labelled mucus macromolecules, and determined the influence of the arachidonic acid pathway using the modified Ussing chamber technique. Zafirlukast (432+/-89.99%) and montelukast (167+/-16.74%) stimulated rat tracheal secretion. This was abolished by application of eicosatetraenoic acid, an inhibitor of the arachidonic acid metabolism. Whereas inhibition of cyclooxygenase did not show any significant effect on zafirlukast induced secretion, blockade of the 5-lipoxygenase pathway markedly reduced the secretagogue effects. Furthermore, inhibition of phosphatidylinositol-3-kinase completely inhibited the effects elicited by zafirlukast. Additional experiments revealed secretagogue effects of zafirlukast also in human bronchial tissue. In conclusion, zafirlukast is a potent inducer of tracheal secretion. Obviously, these effects are induced by involvement of a phosphatidylinositol-3-kinase dependent pathway mediated by products of the arachidonic acid metabolism.

Topics: 5,8,11,14-Eicosatetraynoic Acid; Acetates; Animals; Arachidonic Acid; Bronchi; Chromones; Cyclooxygenase Inhibitors; Cyclopropanes; Dose-Response Relationship, Drug; Humans; Ibuprofen; Indoles; Leukotriene Antagonists; Lipoxygenase Inhibitors; Male; Membrane Proteins; Morpholines; Phenylcarbamates; Phosphoinositide-3 Kinase Inhibitors; Quinolines; Rats; Rats, Sprague-Dawley; Receptors, Leukotriene; Sulfides; Sulfonamides; Tosyl Compounds; Trachea

We investigated whether leukotrienes mediate cell influx and articular incapacitation in zymosan-induced arthritis. Rats received 1 mg zymosan intra-articularly (i.a.). The hyperalgesia was measured using the rat articular incapacitation test. Cell influx, leukotriene B(4) and prostaglandin E(2) levels were assessed in the joint exudate, at 6 h. Groups received either the leukotriene B(4) synthesis inhibitor MK 886 (3-[1-(4-chlorobenzyl)-3-t-butyl-thio-5-isopropylindol-2-yl)]-2,2-dimethylpropanoic acid 30 min before or 2 h after the zymosan; 0.3-3 mg kg(-1) i.p.), the leukotrienes synthesis inhibitor BWA(4)C (N-(3-phenoxycinnamyl)-acetohydroxamic acid--2 h after the zymosan; 10 microg i.a.) or the peptido-leukotrienes antagonist sodium montelukast (30 min before and 2 h after the zymosan; 10 mg kg(-1) per os). MK 886 inhibited the articular incapacitation and cell influx, while reducing leukotriene B(4), but not prostaglandin E(2) levels. BWA(4)C inhibited the articular incapacitation. Sodium montelukast did not affect either of the parameters. The data suggest that leukotriene B(4) is involved in cell influx and articular incapacitation in zymosan arthritis.

Topics: Acetates; Animals; Arthritis, Experimental; Benzeneacetamides; Cell Movement; Cyclopropanes; Exudates and Transudates; Hindlimb; Hydroxamic Acids; Indoles; Joints; Leukotriene Antagonists; Leukotriene B4; Male; Quinolines; Rats; Rats, Wistar; Sulfides; Zymosan