HbG200-mediated preinduction of heme oxygenase-1 improves bile flow and ameliorates pericentral downregulation of Bsep and Mrp2 following experimental liver ischemia and reperfusion.

We studied the downregulation of hepatobiliary transport systems and the effect of pharmacological heme oxygenase-1 (HO-1) preinduction by Hemoglobin-Glutamer 200 (HbG200) in cold ischemia-reperfused rat liver (I/R). Cold I/R reduced bile flow in the reperfusion period from 3.10±0.10 ml/3 h to 0.54±0.20 ml/3 h (p<0.05) and biliary taurocholate excretion from 45.9±13.81 µmol/3 h to 1.87±0.46 µmol/3 h (p<0.05). Mrp2, Bsep and Ntcp peak immunofluorescence in pericentral hepatocytes decreased to 79.0±2.6% (p<0.001), 80.6±8.4% (p<0.05) and 65.8±5.0% (p<0.01), respectively. Pre-induction of HO-1 by HbG200 was largely confined to pericentral hepatocytes. HO-1 induction attenuated the decreased bile flow (0.91±0.16 ml/3 h, p<0.05) and canalicular taurocholate secretion (4.33±1.71 µmol/3 h, p<0.05). Bsep and Mrp2 peak immunofluorescence in pericentral hepatocytes was largely restored. Activation of JNK and Fyn by cold I/R was significantly attenuated by HO-1. Inhibiting HO activity by tin protoporphyrin IX after HbG200 administration reversed the effect on bile flow and canalicular transporter expression. In conclusion, pericentral downregulation of Bsep and Mrp2 following cold I/R is ameliorated by inducing HO-1 and was associated with diminished hepatocellular JNK and Fyn signaling. HO-1 may serve as a therapeutic target to attenuate hepatocellular cholestasis following I/R injury.

Small intestine bleeding due to multifocal angiosarcoma.

We report a case of an 84-year-old male patient with primary small intestinal angiosarcoma. The patient initially presented with anemia and melena. Consecutive endoscopy revealed no signs of upper or lower active gastrointestinal bleeding. The patient had been diagnosed 3 years previously with an aortic dilation, which was treated with a stent. Computed tomography suggested an aorto-intestinal fistula as the cause of the intestinal bleeding, leading to operative stent explantation and aortic replacement. However, an aorto-intestinal fistula was not found, and the intestinal bleeding did not arrest postoperatively. The constant need for blood transfusions made an exploratory laparotomy imperative, which showed multiple bleeding sites, predominately in the jejunal wall. A distal loop jejunostomy was conducted to contain the small intestinal bleeding and a segmental resection for histological evaluation was performed. The histological analysis revealed a less-differentiated tumor with characteristic CD31, cytokeratin, and vimentin expression, which led to the diagnosis of small intestinal angiosarcoma. Consequently, the infiltrated part of the jejunum was successfully resected in a subsequent operation, and adjuvant chemotherapy with paclitaxel was planned. Angiosarcoma of the small intestine is an extremely rare malignant neoplasm that presents with bleeding and high mortality. Early diagnosis and treatment are essential to improve outcome. A small intestinal angiosarcoma is a challenging diagnosis to make because of its rarity, nonspecific symptoms of altered intestinal function, nonspecific abdominal pain, severe melena, and acute abdominal signs. Therefore, a quick clinical and histological diagnosis and decisive measures including surgery and adjuvant chemotherapy should be the aim.

Hemoglobin-glutamer 200 reduces reperfusion injury of the cold preserved rat liver by induction of heme oxygenase-1.

Microcirculatory failure after cold liver preservation and reperfusion impairs tissue oxygenation and causes additional organ damage. Hemoglobin-glutamer (HbG) 200 is a hemoglobin-based oxygen carrying solution capable to improve organ oxygenation. The aim of this study was to evaluate its potential to decrease reperfusion injury after cold liver preservation. Therefore, Wistar rat livers were stored at 4 degrees C for 24 h and reperfused in the isolated perfused rat liver model with a sanguineous perfusate for 180 min. The perfusate consisted of rat blood and Krebs-Henseleit solution (Group A), supplemented by either HES 6% (Group B), or HbG (Groups C and D). In Group D heme oxygenase (HO) activity was blocked by intraperitoneal tin protoporphyrin-IX application before organ harvest. HbG supplementation increased the perfusate hemoglobin by 3,3 g/dL. After 180 min reperfusion perfusate alanine aminotransferase levels (72 +/- 27 micro/L) were significantly reduced in Group C, compared with Groups A and B (140 +/- 28 micro/L and 203 +/- 62 micro/L, respectively). These results correlated with a significant increase of HO-1 expression and activity during reperfusion. These effects could be abolished by tin protoporphyrin-IX application. HbG has been proven to be effective to reduce cold liver preservation-reperfusion injury. The positive effect on reperfusion injury depends on the induction of HO-1, which increases the bilirubin production, an important antioxidant acting as intracellular radical scavenger.