PT - JOURNAL ARTICLE AU - Yuka Nakamori AU - Yoshino Komatsu AU - Tohru Kotani AU - Shinji Kojima AU - Koji Takeuchi TI - Pathogenic Importance of Cysteinyl Leukotrienes in Development of Gastric Lesions Induced by Ischemia/Reperfusion in Mice AID - 10.1124/jpet.109.162578 DP - 2010 Apr 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 91--98 VI - 333 IP - 1 4099 - http://jpet.aspetjournals.org/content/333/1/91.short 4100 - http://jpet.aspetjournals.org/content/333/1/91.full SO - J Pharmacol Exp Ther2010 Apr 01; 333 AB - We examined the role of cysteinyl leukotrienes (CysLTs) in the gastric ulcerogenic response to ischemia/reperfusion (I/R) in mice. Experiments were performed in male C57BL/6J mice after 18-h fasting. Under urethane anesthesia, the celiac artery was clamped for 30 min, and then reperfusion was achieved by removing the clamp. The stomach was examined for lesions 60 min thereafter. The severity of I/R-induced gastric damage was reduced by prior administration of pranlukast [CysLT receptor type 1 (CysLT1R) antagonist] as well as 1-[[5′-(3″-methoxy-4″-ethoxycarbonyl-oxyphenyl)-2′,4′-pentadienoyl]aminoethyl]-4-diphenylmethoxypiperidine [TMK688; 5-lipoxygenase (5-LOX) inhibitor]. On the contrary, these lesions were markedly worsened by pretreatment with indomethacin, and this response was abrogated by the coadministration of TMK688 or pranlukast. The gene expression of CysLT1R but not 5-LOX was up-regulated in the stomach after I/R, but both expressions were increased under I/R in the presence of indomethacin. I/R slightly increased the mucosal CysLT content of the stomach, yet this increase was markedly enhanced when the animals were pretreated with indomethacin. The increased CysLT biosynthetic response to indomethacin during I/R was attenuated by TMK688. Indomethacin alone caused a slight increase of CysLT1R expression and markedly up-regulated 5-LOX expression in the stomach. We concluded that I/R up-regulated the expression of CysLT1R in the stomach; CysLTs play a role in the pathogenesis of I/R-induced gastric damage through the activation of CysLT1R; and the aggravation by indomethacin of these lesions may be brought about by the increase of CysLT production and the up-regulation of 5-LOX expression, in addition to the decreased prostaglandin production.