cp-105696 and Reperfusion-Injury

Pharmacological strategies which limit neutrophil recruitment may also limit the damage induced by the reperfusion of an ischemic vascular territory. In the present study, we have investigated the effects of the BLT receptor antagonist, CP-105,696 ((+)-1-(3S,4R)-[3-(4-phenyl-benzyl)-4-hydroxy-chroman-7-yl]-cyclopentane carboxylic acid), on the local, remote and systemic inflammatory changes observed during severe intestinal ischemia (120 min) and reperfusion (120 min) injury. The post-ischemic treatment with CP-105,696 (3 mg/kg) virtually abolished the increase in vascular permeability, but not neutrophil accumulation, in the intestine and lungs. CP-105,696 partially inhibited the reperfusion-induced neutropenia, but failed to affect intestinal haemorrhage or lethality. CP-105,696 had no inhibitory effect on the local and systemic increases in the concentrations of tumour necrosis factor (TNF-alpha), interleukin-1 beta and interleukin-10, but markedly suppressed interleukin-6. Overall, our results show that activation of BLT receptor plays a minor role in the local, remote and systemic injuries following severe ischemia and reperfusion in rats.

Topics: Animals; Benzopyrans; Capillary Permeability; Carboxylic Acids; Disease Models, Animal; Interleukin-1; Interleukin-10; Interleukin-6; Intestinal Mucosa; Intestines; Lung; Male; Neutrophils; Rats; Rats, Wistar; Receptors, Leukotriene B4; Reperfusion Injury; Time Factors; Tumor Necrosis Factor-alpha

Reperfusion of ischemic vascular beds may lead to recruitment and activation of leukocytes, release of mediators of the inflammatory process and further injury to the affected vascular bed and to remote sites. Neutrophils appear to play a major role in the pathophysiology of reperfusion injury. Amongst inflammatory mediators shown to activate neutrophils and induce their recruitment in vivo, much interest has been placed on the role of leukotriene (LT)B(4). Here, we have assessed the effects of the BLT receptor antagonist (+)-1-(3S, 4R)-[3-(4-phenyl-benzyl)-4-hydroxy-chroman-7-yl]-cyclopentane carboxylic acid (CP 105,696) in a model of neutrophil-dependent ischemia and reperfusion injury in the rat. The superior mesenteric artery was isolated and ischemia was induced by its total occlusion for 30 min. After 30 min of reperfusion, injury was assessed by evaluating the extravasation of Evans blue, an index of vascular permeability, and the levels of myeloperoxidase, an index of neutrophil accumulation, in the intestine, mesentery and lung. The neutrophil-dependence of the local (intestine and mesentery) and remote (lung) injury was confirmed by using fucoidin, a selectin blocker, and WT-3, an anti-CD18 monoclonal antibody. Post-ischemic treatment with CP 105,696 dose-dependently inhibited vascular permeability and neutrophil accumulation in the intestine and mesentery. CP 105,696 also blocked the vascular permeability changes, but not neutrophil accumulation, in the lungs after reperfusion injury. Virtually identical results were obtained with another BLT receptor antagonist, 1-(5-ethyl-2-hydroxy-4-(6-methyl-6-(1H-tetrazol-5-yl)-heptoxy++ +)-phenyl )ethanone (LY255283). Our results suggest that post-ischemic treatment with BLT receptor antagonists may inhibit local and remote ischemia and reperfusion injury by blocking both the accumulation and/or activation of neutrophils.

Topics: Animals; Antibodies, Monoclonal; Benzopyrans; Capillary Permeability; Carboxylic Acids; CD18 Antigens; Disease Models, Animal; Dose-Response Relationship, Drug; Evans Blue; Intestinal Mucosa; Intestines; Leukotriene Antagonists; Lung; Male; Mesenteric Artery, Superior; Mesentery; Neutrophils; Peroxidase; Polysaccharides; Rats; Rats, Wistar; Receptors, Leukotriene B4; Reperfusion Injury; Tetrazoles