Infiltration of immune cells with the Title Loaded From File detection of increased numbers of mononuclear macrophages, neutrophils, and mast cells. Although the numbers of these inflammatory cells are well-matched to those in wild ype groups, the plasma levels of IL6, MCP-1, CINC-1/KC increase in CB1??mice, suggesting activation and increased secretion of these inflammatory mediators by immune cells in CB1??mice. As regards the interaction between the CB system and inflammation, controversial reports exist. Most of them support the concept that et al cannabinoids have anti-inflammatory function. For example, Massa F, [24] used different chemicals to induce experimental bowel inflammation, and found that colitis had been more severe in CB1 knockout mice compared to that in wild type mice. Moreover, the pretreatment of wild type mice withCB1 receptor antagonists gave rise to an up-regulated inflammatory response, while CB1 receptor agonists subdued inflammatory response [40]. Other studies also elucidated that endogenous ligands of CB1 receptors, such as anandamide (AEA), 2arachidonoylglycerol (2 G), and palmitoylethanolamide (PEA) were found capable of attenuating inflammation through decreasing proinflammatory cytokine release, inhibiting mast-cell degranulation and reducing edema [22,23,41]. Our present results suggest that the anti-inflammatory action of CB1 in the inflammatory reaction of POI might result from the inhibition of cytokine release, but is independent of immune cell numbers. The mechanisms of the anti-inflammatory effects of cannabinoids on gastrointestinal inflammatory diseases are far from elucidated. It is not clear whether the p38MAPK signaling pathway, the cholinergic anti-inflammatory pathway, or opioids and other systems are involved. CB1 and CB2 receptors were shown to be involved in the regulation of the mitogen-activated protein kinases (MAPKs), including the extracellular signalregulating kinase 1 and 2 (ERK1/2), p38 MAPK and c-Jun Nterminal kinase (JNK). Activated p38MAPK increases the recruitment of immune cells, activates lymphocytes and neutrophils and delays the apoptosis of these cells [42,43], which are the major source of perpetual production of the inflammatory mediators. The present study shows an elevated expression of p38 and its phosphorylated form (pp38) in the intestinal tissues at 24 h POI, and this phenomenon is more pronounced in CB1??animals. Taken together with the significantly elevated plasma levels of inflammatory mediators in CB1??mice, the results suggest that p38 MAPK actively participate in the local and systematic inflammatory response Title Loaded From File during POI. In addition, CB1 receptors are involved in anti-inflammatory regulation by erasing or inhibiting the p38 MAPK activation. In summary, this study has demonstrated in a mouse POI experimental model, that GI transit is reduced in CB1??animals and their wild-type controls. In both types of mice, the inflammatory response which accompanies POI was similar when analyzing the cellular level i. e. immune cell infiltration. However, several chemokines and cytokines gauging the systemic inflammatory response were elevated in CB1??animals compared 23977191 to wildtype controls. In conclusion, although absence of the CB1 receptor did not alter inhibition of GI motility during postoperative ileus, the anti-inflammatory effect was weakened by which POI may be promoted and developed. Hence, CB1 receptor activation rather than inhibition may reduce the inflammatory response in POI, wh.Infiltration of immune cells with the detection of increased numbers of mononuclear macrophages, neutrophils, and mast cells. Although the numbers of these inflammatory cells are well-matched to those in wild ype groups, the plasma levels of IL6, MCP-1, CINC-1/KC increase in CB1??mice, suggesting activation and increased secretion of these inflammatory mediators by immune cells in CB1??mice. As regards the interaction between the CB system and inflammation, controversial reports exist. Most of them support the concept that et al cannabinoids have anti-inflammatory function. For example, Massa F, [24] used different chemicals to induce experimental bowel inflammation, and found that colitis had been more severe in CB1 knockout mice compared to that in wild type mice. Moreover, the pretreatment of wild type mice withCB1 receptor antagonists gave rise to an up-regulated inflammatory response, while CB1 receptor agonists subdued inflammatory response [40]. Other studies also elucidated that endogenous ligands of CB1 receptors, such as anandamide (AEA), 2arachidonoylglycerol (2 G), and palmitoylethanolamide (PEA) were found capable of attenuating inflammation through decreasing proinflammatory cytokine release, inhibiting mast-cell degranulation and reducing edema [22,23,41]. Our present results suggest that the anti-inflammatory action of CB1 in the inflammatory reaction of POI might result from the inhibition of cytokine release, but is independent of immune cell numbers. The mechanisms of the anti-inflammatory effects of cannabinoids on gastrointestinal inflammatory diseases are far from elucidated. It is not clear whether the p38MAPK signaling pathway, the cholinergic anti-inflammatory pathway, or opioids and other systems are involved. CB1 and CB2 receptors were shown to be involved in the regulation of the mitogen-activated protein kinases (MAPKs), including the extracellular signalregulating kinase 1 and 2 (ERK1/2), p38 MAPK and c-Jun Nterminal kinase (JNK). Activated p38MAPK increases the recruitment of immune cells, activates lymphocytes and neutrophils and delays the apoptosis of these cells [42,43], which are the major source of perpetual production of the inflammatory mediators. The present study shows an elevated expression of p38 and its phosphorylated form (pp38) in the intestinal tissues at 24 h POI, and this phenomenon is more pronounced in CB1??animals. Taken together with the significantly elevated plasma levels of inflammatory mediators in CB1??mice, the results suggest that p38 MAPK actively participate in the local and systematic inflammatory response during POI. In addition, CB1 receptors are involved in anti-inflammatory regulation by erasing or inhibiting the p38 MAPK activation. In summary, this study has demonstrated in a mouse POI experimental model, that GI transit is reduced in CB1??animals and their wild-type controls. In both types of mice, the inflammatory response which accompanies POI was similar when analyzing the cellular level i. e. immune cell infiltration. However, several chemokines and cytokines gauging the systemic inflammatory response were elevated in CB1??animals compared 23977191 to wildtype controls. In conclusion, although absence of the CB1 receptor did not alter inhibition of GI motility during postoperative ileus, the anti-inflammatory effect was weakened by which POI may be promoted and developed. Hence, CB1 receptor activation rather than inhibition may reduce the inflammatory response in POI, wh.
