Submitted on August 4, 2006
Accepted on October 2, 2006
Role of the thrombin/protease-activated receptor 1 pathway in intestinal ischemia-reperfusion injury in rats
Hisato Tsuboi1, Yuji Naito2*, Kazuhiro Katada3, Tomohisa Takagi4, Osamu Handa4, Satoshi Kokura4, Hiroshi Ichikawa5, Norimasa Yoshida6, Minoru Tsukada7, and Toshikazu Yoshikawa8
1 Department of Inflammation and Immunology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan
2 Medical Proteomics, Kyoto Prefectural University of Medicine, Kyoto, Japan
3 Kyoto, Japan; Department of Inflammation and Immunology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan
4 Biomedical Safety Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
5 Department of Food Sciences and Nutritional Health, The Faculty of Human Environment, Kyoto Prefectural University, Kyoto, Japan
6 Molecular Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Kyoto, Japan
7 Hirakata Research Laboratory, Research and Development Division, Benesis Corporation, Kyoto, Japan
8 Department of Inflammation and Immunology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan; Medical Proteomics, Kyoto Prefectural University of Medicine, Kyoto, Japan; Biomedical Safety Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
* To whom correspondence should be addressed. E-mail: ynaito{at}koto.kpu-m.ac.jp.
CXC chemokines, including human interleukin-8 and rat cytokine-induced neutrophil chemoattractant-1 (CINC-1), play a crucial role in the pathogenesis of intestinal inflammation induced by ischemia-reperfusion (I-R). Thrombin and its specific receptor, protease-activated receptor 1 (PAR1), act as important players in inflammation. However, the association between thrombin activation and chemokine production during I-R has not been well studied. We investigated whether thrombin and PAR1 might be involved in the pathophysiology of intestinal I-R, using an in vivo model. Intestinal damage was induced by clamping the superior mesenteric artery for 30 min followed by reperfusion in male Wistar rats. Thrombin-antithrombin complex (TAT) was measured as an indicator of thrombin activation. PAR1 expression in the intestine was evaluated by real time-PCR. The severity of the intestinal mucosal injury was evaluated on the distal segment of the ileum by several biochemical markers and histological findings. Reperfusion significantly increased the serum levels of TAT and enhanced PAR1 expression in the intestinal mucosa. The levels of both intraluminal hemoglobin and protein were significantly increased in the I-R group. The mucosal myeloperoxidase activity and expressions/productions of CINC-1 and tumor necrosis factor-
were significantly increased after I-R. These increases were inhibited by the treatment of rat with antithrombin (AT) intravenously prior to I-R at a dose of 30 U/kg. These results suggest that the thrombin/PAR1 pathway plays an important role in the production of these cytokines during I-R, and that AT exerts potent anti-inflammatory effects on this injury via inhibition of pro-inflammatory cytokines.
