Effects of octreotide on intestinal transit and bacterial translocation in conscious rats with portal hypertension and liver fibrosis

The Effect of Curcumin on an Animal Intestinal Ischemia/Reperfusion Model for Bacterial Translocation and Inflammatory Response

Ischemia/reperfusion (IR) injury of the intestine is a major problem in abdominal pathological condition and is associated with a high morbidity and mortality. The purpose of the study is to investigate the effects of curcumin on the bacterial translocation incidence and inflammatory response in rats submitted to bowel ischemia reperfusion injury. Thirty-two Wistar albino rats with a weight of 200 to 250 g were used in the study. They were randomly divided into 3 groups (n = 10 for each group): sham only operated group(group I); IR group (group II); and IR + curcumin treatment group (group III). Curcumin (curcumin from Curcuma longa) 20 mg/kg/day was given orally to the curcumin group. All animals were given 109 E. Coli by orogastric intubation 12 hours before sampling. Seventy-two hours after the first operation, mesenteric lymph node and blood samples were obtained and cultured. Blood samples of 2 mL were obtained for a polymerase chain reaction study. A piece of terminal ileum was also sampled for histopathologic examination. Mesenteric lymph node and blood cultures of all control animals were positive for microbiological growth, and polymerase chain reaction results were positive in seven of the eight rats. Histopathologically, edema, vasodilatation and inflammatory cell infiltration were found to be less in the other groups in comparison to the control group. Curcumin reduced bacterial translocation in blood, hepatocellular damage, and plasma cytokine levels. Curcumin reduced the incidence of bacterial translocation in intestinal I/R. rats. These results suggest that Curcumin would be clinically useful in the treatment of intestinal I/R injury.

Effect of melatonin and misoprostol on bacterial translocation in portal hypertensive rats

BACKGROUND AND AIM

Portal hypertension is the main complication of cirrhosis and it is responsible for its most common complications. Bacterial translocation increases the morbidity and mortality rates in patients with portal hypertension. We aimed to investigate the effects of melatonin and misoprostol on bacterial translocation induced by portal hypertension.

METHODS

We established four groups, each containing eight rats. Except for the control and sham groups, the animals in the other groups (treatment groups) received misoprostol or melatonin for 3 days after the first operation. In the sham group, a laparotomy was carried out and only the portal vein was dissected. Calibrated portal vein ligation was carried out in the other groups. All animals were given 10(10) Escherichia coli by orogastric intubation 12 h before sampling. Seventy-two hours after the first operation, mesenteric lymph node and blood samples were obtained and cultured. Two cc blood samples were obtained for a polymerase chain reaction study. A piece of terminal ileum was also sampled for histopathologic examination.

RESULTS

Mesenteric lymph node and blood cultures of all control animals were positive for microbiological growth, and polymerase chain reaction results were positive in seven of the eight rats. Histopathologically, edema, vasodilatation and inflammatory cell infiltration were found to be less in the other groups in comparison to the control group. The incidence of bacterial translocation was decreased in all treatment groups as compared to the control group.

CONCLUSIONS

In this study, bacterial translocation occurred in portal hypertension. Melatonin and misoprostol reduced the incidence of bacterial translocation in portal hypertensive rats.

Acute pancreatitis, bacterial translocation, and different octreotide regimens: an experimental study

PURPOSE

To determine the effect of octreotide, octreotide with zinc, levamisole, and misoprostol on the bacterial translocation that develops in rats with acute pancreatitis (AP).

METHODS

A total of 36 rats were divided into six groups, each consisting of six rats. Only laparotomy was performed on the first group. Acute pancreatitis was performed on the second group. Octreotide was given to the third, fourth, fifth, and sixth groups. Octreotide, octreotide with zinc, levamisole, and misoprostol were given to groups III, IV, V, VI, respectively. Rats were euthanized 48 h after the occurrence of AP. Blood and mesenteric lymph node samples were collected for polymerase chain reaction (PCR). Pancreatic tissue and terminal ileum were obtained for histopathological examinations.

RESULTS

The severity of pancreatitis and mucosal damage of the terminal ileum was higher in group II than groups I, III, IV, V, and VI, histopathologically (P < 0.05). There wasn't a significant difference with respect to OA with Zn or L or M and OA group (P > 0.05). A significant difference was found in PCR positivity in blood and mesenteric lymph node between groups I and II (P < 0.05).

CONCLUSIONS

In AP, administering octreotide alone significantly prevented the bacterial translocation by preventing mucosal damage. The zinc, levamisole, or misoprostol with octreotide did not influence the results.

Kampo medicine "Dai-kenchu-to" prevents bacterial translocation in rats

Kampo medicine "Dai-kenchu-to" (DKT) has been used for treatment of ileus. The aim of this study was to evaluate the role of DKT on the bacterial translocation (BT) model in rats. Rats were divided into the following four groups: group 1, receiving only water, and groups 2, 3, and 4, receiving 100, 300, and 1,000 mg/kg/day of DKT. Rats were sacrificed 6 days after the beginning of the fast, and then the mesenteric lymph node was cultured. Inflammatory cytokines, intestinal integrity, and apoptosis were assessed. Incidence of BT in groups 3 (33%) and 4 (16%) was lower than in group 1 (66%). Interferon-gamma expression in groups 2, 3, and 4 was significantly lower than in group 1. Villous height and number of villus in groups 2, 3, and 4 were significantly taller and greater than in group 1. Apoptotic index in groups 2, 3, and 4 was significantly lower than in group 1. This is the first evidence that DKT prevents BT by reducing inflammatory reaction and maintaining intestinal integrity.

The role of food restriction on CCl4-induced cirrhosis model in rats

Effects of food restriction on susceptibility to the toxic effect of some chemicals are controversial. In order to identify an exposure model that could maximize cirrhosis and minimize mortality rate, this study aimed to evaluate the effect of food restriction on tetrachloride carbon (CCl(4))-induced cirrhosis model in rats. Fifty-three male Wistar rats received CCl(4) 0.25 ml/kg weekly intragastrically once a week. Thirty-three had 44% food restriction (group 1); 10 rats had 25% food restriction (group 2); and 10 rats received ad libitum food (group 3). After 10 weeks, the animals were sacrificed and liver sections were collected for histology. Of the 53 animals enrolled for the study, 22 (41.5%) died before completing 10-week CCl(4). Mortality rate was significantly higher in group 1 compared to other groups (p<0.05). Cirrhosis was significantly more prevalent in group 1 than in group 3 (p<0.01), but without significant difference between groups 1 and 2 (p=0.624). We concluded that food restriction is an important issue to be considered when establishing a CCl(4)-induced cirrhosis model in rats. Moreover, there is an ideal range of food intake that predisposes to liver damage without increasing mortality leading to a more effective model.

Infection et rupture de varice œsophagienne au cours de la cirrhose

Endotoxemia and bacterial infection are frequent in patients with cirrhosis. They alter systemic and splanchnic hemodynamics, worsen coagulation disorders, impair liver function and thus may induce variceal bleeding. In variceal bleeding, bacterial infection favours failure to control bleeding, early rebleeding, and death. In patients with cirrhosis and variceal bleeding, antibiotic-prophylaxis decreases bacterial infection and the incidence of early rebleeding, and, more important, significantly decreases the death rate in these patients.

Morphological and serum hyaluronic acid, laminin and type IV collagen changes in dimethylnitrosamine-induced hepatic fibrosis of rats

AIM

To study the morphological and serum hyaluronic acid (HA), laminin (LN), and type IV collagen changes in hepatic fibrosis of rats induced by dimethylnitrosamine (DMN).

METHODS

The rat model of liver fibrosis was induced by DMN. Serum HA, type IV collagen, and LN were measured by ELISA. The liver/weight index and morphological changes were examined under electron microscope on d 7, 14, 21, and 28 by immunohistochemical alpha smooth muscle actin alpha-SMA staining as well as Sirius-red and HE staining.

RESULTS

The levels of serum HA, type IV collagen and LN significantly increased from d 7 to d 28 (P = 0.043). The liver/weight index increased on d 7 and decreased on d 28. In the model group, the rat liver stained with HE and Sirius-red showed evident hemorrhage and necrosis in the central vein of hepatic 10 lobules on d 7. Thin fibrotic septa were formed joining central areas of the liver on d 14. The number of alpha-SMA positive cells was markedly increased in the model group. Transitional hepatic stellate cells were observed under electron microscope. All rats in the model group showed micronodular fibrosis in the hepatic parenchyma and a network of alpha-SMA positive cells. Typical myofibroblasts were embedded in the core of a fibrous septum. Compared to the control group, the area-density percentage of collagen fibrosis and pathologic grading were significantly different in the model group (P<0.05) on different d (7, 14, and 28). The area-density percentage of collagen fibrosis in hepatic tissue had a positive correlation with the levels of serum HA, LN, and type IV collagen.

CONCLUSION

The morphological and serum HA, type IV collagen, and LN are changed in DMN-induced liver fibrosis in rats.

Gut microflora in the pathogenesis of the complications of cirrhosis

The gut flora plays an important role in the pathogenesis of the complications of cirrhosis. Cirrhotic patients are prone to develop bacterial infections, mainly the 'spontaneous' infection of ascites or spontaneous bacterial peritonitis. Other complications of cirrhosis, such as variceal haemorrhage and ascites, occur mostly or solely as a consequence of portal hypertension. Portal pressure increases initially as a consequence of an increased intrahepatic resistance but, once collaterals have formed, high portal pressure is maintained by an increased splanchnic blood inflow secondary to vasodilatation. Splanchnic vasodilatation is the initiating event in the hyperdynamic circulatory state that aggravates the complications of cirrhosis. The gut flora plays a role in both the development of infections and in the hyperdynamic circulatory state of cirrhosis and, although less prominently, it also plays a role in the pathogenesis of hepatic encephalopathy. This chapter presents evidence regarding gut flora and its modification in the pathogenesis and management of these complications of cirrhosis.

Effect of cisapride on intestinal bacterial and endotoxin translocation in cirrhosis

AIM: To investigate the effects of cisapride on intestinal bacterial overgrowth (IBO), bacterial and endotoxin translocation, intestinal transit and permeability in cirrhotic rats.

METHODS: All animals were assessed with variables including bacterial and endotoxin translocation, intestinal bacterial overgrowth, intestinal transit and permeability. Bacterial translocation (BT) was assessed by bacterial culture of MLN, liver and spleen, IBO by a jejunal bacterial count of the specific organism, intestinal permeability by determination of the 24-hour urinary ^99mTc-DTPA excretion and intestinal transit by measurement of the distribution of ⁵¹Cr in the intestine.

RESULTS: Bacterial translocation (BT) and IBO was found in 48% and 80% cirrhotic rats respectively and none in control rats. Urinary excretion of ^99mTc-DTPA in cirrhotic rats with BT (22.2 ± 7.8) was greater than these without BT (10.5 ± 2.9). Intestinal transit (geometric center ratio) was significantly delayed in cirrhotic rats (0.31 ± 0.06) and further more delayed in cirrhotic rats with BT (0.24 ± 0.06) than these without BT (0.38 ± 0.11). Cirrhotic rats with IBO had significantly higher rates of intestinal bacterial and endotoxin translocation, slower intestinal transit time and higher intestinal permeability than those without IBO. It was also found that BT was closely associated with IBO and the injury of intestinal barrier. Compared with the placebo group, cisapride-treated rats had lower rates of bacterial/endotoxin translocation and IBO, which was closely associated with increased intestinal transit and improved intestinal permeability by cisapride.

CONCLUSION: These results indicate that endotoxin and bacterial translocation in cirrhotic rats may be attributed to IBO and increased intestinal permeability. Cisapride that accelerates intestinal transit and improve intestinal permeability might be helpful in preventing intestinal bacterial and endotoxin translocation.

Effects of octreotide acetate and Saccharomyces boulardii on bacterial translocation in an experimental intestinal loop obstruction model of rats

Intestinal obstruction (IO) induces bacterial translocation (BT) due to mucosal disruption, motility dysfunction, and increased intestinal volume, leading to bacterial overgrowth. This study was conducted to investigate the effects of octreotide acetate (OA) and Saccharomyces boulardii (SB) on the BT and intestinal integrity in an animal model of intestinal loop obstruction (LO). Forty adult male Sprague-Dawley rats (250-300 g) were randomized into 4 groups containing 10 rats each. Complete IO was created in the distal ileum of rats by a single 3-0 silk suture (LO). Group Sham: Sham (Laparotomy only was performed in this group); group LO: LO; group OA: LO plus OA (100 microg/kg, at 0, 12 hours of obstruction); group (SB): LO plus SB (800 mg/kg/day, via orogastric and preoperative for 3 days). After 24 hours, samples of mesenteric lymph nodes (MLN), liver, spleen and blood were obtained and cultured. The terminal ileum specimens were examined histopathologically. There were no BT in group Sham, but BT was noticed totally in 31 (77.5%) cultures in group LO. This rate was reduced to 30% (n = 12), 10% (n = 4) in the groups OA and SB respectively. Bacterial translocations of MLN and the liver in group LO were significantly higher than those of groups OA and SB. Bacterial translocations of the both spleen and blood in group LO were significantly higher than those of groups OA and SB. The mean bacterial counts, colony-forming units per gram tissue (cfu/g), in the MLN, liver and spleen of group LO were found significantly higher than those of groups OA and SB. The mean villus height in group OA was significantly higher than that of group LO and it in the group SB significantly higher than those of groups LO and OA. The present experimental study has demonstrated that OA and SB may have protective effects against BT in mechanical bowel obstruction and additionally SB preserves intestinal mucosal integrity.