Ligustrazine alleviates gastric mucosal injury in a rat model of acute necrotizing pancreatitis

BACKGROUND: Acute necrotizing pancreatitis (ANP) leads to a systemic inflammatory response characterized by widespread leukocyte activation and, as a consequence, distant organ injury. The aim of this study was to explore the relationship between gastric microcirculatory impairment and inflammatory mediators released in rats and to evaluate the therapeutic effect of ligustrazine extracted from Rhizoma ligusticum wallichii on gastric mucosa injury in a rat model of ANP. METHODS: Ninety-six Sprague-Dawley rats were randomly divided into three groups: normal control (group Q; ANP without treatment (group P); and ANP treated with ligustrazine (group T). The ANP model was induced by injection of 50 g/L sodium taurocholate under the pancreatic membrane (4 ml/kg). Group C was given isovolumetric injection of 9 g/L physiological saline by the same route. Group T was injected with ligustrazine (10 ml/kg) via the portal vein. The radioactive biomicrosphere technique was used to measure the blood flow 2 and 12 hours after the induction of ANP. Samples of the pancreas and stomach were taken to assess pathological changes by a validated histology score; meanwhile, the levels of serum interleukin-1 beta (IL-1 beta) were determined. Gastric tissues were also used to measure the level of myeloperoxidase (MPO), which is expressed intracellularly in the azurophilic granules of neutrophils. RESULTS: Blood flow in group P was significantly lower than that in group C (P < 0.01). Pathological changes were significantly aggravated in group P. The gastric MPO activity in group P was significantly higher than that in group C (P < 0.01). The level of serum IL-1 beta in group P increased more significantly than that in group C (P < 0.01). Blood flow of the stomach in group T was significantly higher than that in group P after 2 hours (P < 0.01). The pathological changes were significantly alleviated in group T. The MPO activity of group T was significantly lower than that of group P (P < 0.01). Although serum IL-1 beta level of group T, was higher than of group C (P < 0.01), it was lower than that of group P (P < 0.01). There was a negative correlation between gastric blood flow and MPO activity (r=-0.983, P < 0.01), and between gastric blood flow and pathological score (r=-0.917, P < 0.05). CONCLUSIONS: Decreased gastric blood flow and increased inflammatory mediators can be seen early in ANP, and both are important factors for gastric and mucosal injury. Ligustrazine can ameliorate microcirculatory disorder and alleviate the damage to the pancreas and stomach.

MRI shows clodronate-liposomes attenuating liver injury in rats with severe acute pancreatitis

BACKGROUND: Studies have revealed that macrophages play an important role in the development of severe acute pancreatitis (SAP). Activated macrophages can lead to a systemic inflammatory response, induce lipid peroxidation, impair membrane structure, result in injury to the liver and the other extrahepatic organs, and eventually result in multiple organ dysfunction syndrome by promoting excessive secretion of cytokines. Liver injury can further aggravate the systemic inflammatory response and increase mortality by affecting the metabolism of toxins and the release of excessive inflammatory mediators. Clodronate is a synthetic bisphosphonate, which is often used for treating bone changes caused by osteoporosis and other factors. In the current study, we created liposomes containing superparamagnetic iron oxide particles (SPIOs) for macrophage labeling and magnetic resonance imaging, using a novel method that can bind the clodronate to induce apoptosis and deplete macrophages. METHODS: Superparamagnetic Fe(3)O(4) nanoparticles were prepared by chemical coprecipitation. SPIO-containing liposomes and SPIO-clodronate-containing liposomes were prepared by the thin film method. SAP models were prepared by injection of sodium taurocholate (2 ml/kg body weight) into the subcapsular space of the pancreas. Sprague-Dawley rats were randomly divided into a control group, a SAP plus SPIO-liposome group, and a SAP plus SPIO-clodronate-containing group. Two and six hours after SAP models were available, T2-weighted MRI scans (in the same plane) of the livers of rats in each group were performed. At the end of the scans, 2 ml of blood was taken from the superior mesenteric vein to measure the levels of serum amylase, ALT, AST, TNF-alpha, and IL-6. Pathological changes in the liver and pancreas were assessed. RESULTS: Transmission electron microscopy showed that the liposomes had a uniform size. No pathological changes in the pancreata of rats in the control group were noted. The pathological changes in the pancreata and livers of rats in the SAP plus SPIO-clodronate-containing liposome group were milder than those in the SAP plus SPIO-liposome group. The MRI signal intensity of the livers in the SAP plus SPIO-liposome and SAP plus SPIO-clodronate-containing groups was significantly lower than that in the control group. There were significant changes in the two experimental groups (P<0.01). In addition, the levels of serum amylase, ALT, AST, TNF-alpha, and IL-6 in rats in the SAP plus SPIO-liposome group were higher than those in the control group (P<0.01), while the corresponding levels in the SPIO-clodronate-containing liposome group were significantly lower than those in the SAP plus SPIO-liposome group (P<0.01). CONCLUSION: Clodronate-containing liposomes protect against liver injury in SAP rats, and SPIO can be used as a tracer for MRI examination following liver injury in SAP rats. (Hepatobiliary Pancreat Dis Int 2010; 9: 192-200)