AIM: To describe the pathophysiology, clinical presentation, natural history, and therapy of portal hypertensive gastropathy(PHG) based on a systematic literature review.METHODS: Computerized search of the literature ...AIM: To describe the pathophysiology, clinical presentation, natural history, and therapy of portal hypertensive gastropathy(PHG) based on a systematic literature review.METHODS: Computerized search of the literature was performed via Pub Med using the following medical subject headings or keywords: "portal" and "gastropathy"; or "portal" and "hypertensive"; or "congestive" and "gastropathy"; or "congestive" and "gastroenteropathy". The following criteria were applied for study inclusion: Publication in peer-reviewed journals, and publication since 1980. Articles were independently evaluated by each author and selected for inclusion by consensus after discussion based on the following criteria: Well-designed, prospective trials; recent studies; large study populations; and study emphasis on PHG. RESULTS: PHG is diagnosed by characteristic endoscopic findings of small polygonal areas of variable erythema surrounded by a pale, reticular border in a mosaic pattern in the gastric fundus/body in a patient with cirrhotic or non-cirrhotic portal hypertension. Histologic findings include capillary and venule dilatation, congestion, and tortuosity, without vascular fibrin thrombi or inflammatory cells in gastric submucosa. PHG is differentiated from gastric antral vascular ectasia by a different endoscopic appearance. The etiology of PHG is inadequately understood. Portal hypertension is necessary but insufficient to develop PHG because many patients have portal hypertension without PHG.PHG increases in frequency with more severe portal hypertension, advanced liver disease, longer liver disease duration, presence of esophageal varices, and endoscopic variceal obliteration. PHG pathogenesis is related to a hyperdynamic circulation, induced by portal hypertension, characterized by increased intrahepatic resistance to flow, increased splanchnic flow, increased total gastric flow, and most likely decreased gastric mucosal flow. Gastric mucosa in PHG shows increased susceptibility to gastrotoxic chemicals and poor wound healing. Nitrous oxide, free radicals, tumor necrosis factor-alpha, and glucagon may contribute to PHG development. Acute and chronic gastrointestinal bleeding are the only clinical complications. Bleeding is typically mild-to-moderate. Endoscopic therapy is rarely useful because the bleeding is typically diffuse. Acute bleeding is primarily treated with octreotide, often with concomitant proton pump inhibitor therapy, or secondarily treated with vasopressin or terlipressin. Nonselective β-adrenergic receptor antagonists, particularly propranolol, are used to prevent bleeding after an acute episode or for chronic bleeding. Iron deficiency anemia from chronic bleeding may require iron replacement therapy. Transjugular-intrahepaticportosystemic-shunt or liver transplantation is highly successful ultimate therapies because they reduce the underlying portal hypertension.CONCLUSION: PHG is important to recognize in patients with cirrhotic or non-cirrhotic portal hypertension because it can cause acute or chronic GI bleeding that often requires pharmacologic therapy.展开更多
AIM: To analyze reliability among endoscopists in diagnosing portal hypertensive gastropathy (PHG) and to determine which criteria from the most utilized classifications are the most suitable. METHODS: From January to...AIM: To analyze reliability among endoscopists in diagnosing portal hypertensive gastropathy (PHG) and to determine which criteria from the most utilized classifications are the most suitable. METHODS: From January to July 2009, in an academic quaternary referral center at Santa Casa of S o Paulo Endoscopy Service, Brazil, we performed this singlecenter prospective study. In this period, we included 100 patients, including 50 sequential patients who had portal hypertension of various etiologies; who were previously diagnosed based on clinical, laboratory and imaging exams; and who presented with esophageal varices. In addition, our study included 50 sequentialpatients who had dyspeptic symptoms and were referred for upper digestive endoscopy without portal hypertension. All subjects underwent upper digestive endoscopy, and the images of the exam were digitally recorded. Five endoscopists with more than 15 years of experience answered an electronic questionnaire, which included endoscopic criteria from the 3 most commonly used Portal Hypertensive Gastropathy classifications (McCormack, NIEC and Baveno) and the presence of elevated or flat antral erosive gastritis. All five endosco- pists were blinded to the patients' clinical information, and all images of varices were deliberately excluded for the analysis. RESULTS: The three most common etiologies of portal hypertension were schistosomiasis (36%), alcoholic cirrhosis (20%) and viral cirrhosis (14%). Of the 50 patients with portal hypertension, 84% were Child A, 12% were Child B, 4% were Child C, 64% exhibited previous variceal bleeding and 66% were previously endoscopic treated. The endoscopic parameters, presence or absence of mosaic-like pattern, red point lesions and cherry-red spots were associated with high inter-observer reliability and high specificity for diagnosing Portal Hypertensive Gastropathy. Sensitivity, specificity and reliability for the diagnosis of PHG (%) were as follows: mosaic-like pattern (100; 92.21; High); fine pink speckling (56; 76.62; Unsatisfactory); superficial reddening (69.57; 66.23; Unsatisfactory); red-point lesions (47.83; 90.91; High); cherry-red spots (39.13; 96.10; High); isolated red marks (43.48; 88.31; High); and confluent red marks (21.74; 100; Unsatisfactory). Antral elevated erosive gastritis exhibited high reliability and high specificity with respect to the presence of portal hypertension (92%) and the diagnosis of portal hypertensive gastropathy (88.31%). CONCLUSION: The most suitable endoscopic criteria for the diagnosis of PHG were mosaic-like pattern, redpoint lesions and cherry-red spots with no subdivisions,which were associated with a high rate of inter-observer reliability.展开更多
AIM:To investigate any protective effect of early propranolol administration in the development of portal hypertensive gastropathy in cirrhotic rats. METHODS:For the development of liver cirrhosis and portal hypertens...AIM:To investigate any protective effect of early propranolol administration in the development of portal hypertensive gastropathy in cirrhotic rats. METHODS:For the development of liver cirrhosis and portal hypertensive gastropathy,60 rats underwent ligation of the left adrenal vein and complete devascularization of the left renal vein,followed by phenobarbital and carbon tetrachloride(CCl4) administration.After two weeks of CCl4 administration, the rats were randomly separated into two groups.In group A,propranolol was continuously administered intragastrically throughout the study,whereas in group B normal saline(placebo)was administered instead. Hemodynamic studies and vascular morphometric analysis of gastric sections were performed after complete induction of cirrhosis. RESULTS:Vascular morphometric studies showed higher numbers of vessels in all mucosal layers in the control group.Statistical analysis revealed a significantly higher total vascular surface in the control group compared to the propranolol group,but with no statistically significant difference between the mean vascular surfaces between the groups.Our study clearly shows that the increased mucosal blood flow is manifested by a marked increase of vessel count. CONCLUSION:Early propranolol's administration in portal hypertensive cirrhotic rats seems to prevent intense gastric vascular congestion that characterizes portal hypertensive gastropathy.展开更多
To the Editor:H. pylori lives in the gastric epithelial cells, sometimes in gastric glands.Whetherornottheproliferationandbiologicalbehavior of H. pylori can be influenced by the status of the gastric mucosa is still ...To the Editor:H. pylori lives in the gastric epithelial cells, sometimes in gastric glands.Whetherornottheproliferationandbiologicalbehavior of H. pylori can be influenced by the status of the gastric mucosa is still unknown. Portal hypertensive gastropathy (PHG) is a blood drainage obstructive disease. In this pathologic environment, gastric mucosa may be further impaired when patients are infected with H. pylori. The role of H. pylori in the pathogenesis of PHG and展开更多
Objective:To study the role and the mechanism of endotoxin in the pathogenesis of gastric mucosa during portal vein hypertension gastrography(PHG) in the rats with cirrhosis.Methods: Rat model for PHG was established ...Objective:To study the role and the mechanism of endotoxin in the pathogenesis of gastric mucosa during portal vein hypertension gastrography(PHG) in the rats with cirrhosis.Methods: Rat model for PHG was established by injection of tetrachloride.The animals were injected with endotoxin i.p.at 3 mg/kg and endotoxin antagonist BPI21 i.v.at 2.0 mg/kg.The plasma level of endotoxin as well as the gastric mucosal level of tumor necrosis factor alpha(TNF-α) was measured with azobenzene and ELISA respectively.Furthermore,the pathological changes of the gastric mucosa were studied with HE stainning.Results:In rats with PHG,increased endotoxin and TNF-αas well as the gastric pathological lesion were observed.Injection of endotoxin remarkably increased plasma level of endotoxin as well as the gastric mucosal level of tumor necrosis TNF-αand induced more serious gastric lesion.Animals injected with endotoxin antagonist BPI21 showed improved gastric mucosal lesion,accompanied by the declining TNF-αlevel.Conclusions:Our results suggestes that endotoxin may play a pathogenetic role in PHG by inducing the expression of TNF-α.展开更多
BACKGROUND Accurate detection of gastric antral vascular ectasia(GAVE)is critical for proper management of cirrhosis-related gastrointestinal bleeding.However,endoscopic diagnosis of GAVE can be challenging when GAVE ...BACKGROUND Accurate detection of gastric antral vascular ectasia(GAVE)is critical for proper management of cirrhosis-related gastrointestinal bleeding.However,endoscopic diagnosis of GAVE can be challenging when GAVE overlaps with severe portal hypertensive gastropathy(PHG).AIM To determine the added diagnostic value of virtual chromoendoscopy to high definition white light for real-time endoscopic diagnosis of GAVE and PHG.METHODS We developed an I-scan virtual chromoendoscopy criteria for diagnosis of GAVE and PHG.We tested our criteria in a cross-sectional cohort of cirrhotic adults with GAVE and PHG when high-definition white light endoscopy(HDWLE)diagnosis was in doubt.We then compared the accuracy of I-scan vs HDWLE alone to histology.RESULTS Twenty-three patients were included in this study(65.2%Caucasians and 60.9%males).Chronic hepatitis C was the predominant cause of cirrhosis(43.5%)and seven adults(30.4%)had confirmed GAVE on histology.I-scan had higher sensitivity(100%vs 85.7%)and specificity(75%vs 62.5%)in diagnosing GAVE compared to HDWLE.This translates into a higher,albeit not statistically significant,accuracy of I-scan in detecting GAVE compared to HDWLE alone(82%vs 70%).I-scan was less likely to lead to an accurate diagnosis of GAVE in patients on dialysis(P<0.05)and in patients with elevated creatinine(P<0.05).Iscan had similar accuracy to HDWLE in detecting PHG.CONCLUSION This pilot work supports that virtual chromoendoscopy may obviate the need for biopsies when the presence of GAVE is in doubt.Larger studies are needed to assess the impact of virtual chromoendoscopy on success of endoscopic therapy for GAVE.展开更多
AIM: To evaluate the antioxidant effect of N-acetylcysteine(NAC) on the stomach of rats with portal hypertension.METHODS: Twenty-four male Wistar rats weighing ± 250 g were divided into four experimental groups(n...AIM: To evaluate the antioxidant effect of N-acetylcysteine(NAC) on the stomach of rats with portal hypertension.METHODS: Twenty-four male Wistar rats weighing ± 250 g were divided into four experimental groups(n =6 each): Sham-operated(SO),SO + NAC,partial portal vein ligation(PPVL),and PPVL + NAC. Treatment with NAC in a dose of 10 mg/kg(i.p.) diluted in 0.6 m L of saline solution was administered daily for 7 d starting 8 d after the surgery. Animals from the PPVL and SO group received saline solution(0.6 m L) for the same period of time as the PPVL + NAC and SO + NAC group. On the 15 th day the animals were anesthetized and we evaluated portal pressure by cannulating mesenteric artery. After,we removed the stomach for further analysis. We performed immunohistochemical analysis for endothelial nitric oxide synthase(e NOS),vascular endothelial growth factor(VEGF),and nitrotirosine(NTT) proteins in stomach. We also evaluated e NOS and VEGF by Western blot analysis and assessed DNA damage in blood samples by the comet assay.RESULTS: The portal hypertension group exhibited increases in portal pressure when compared to SO group(29.8 ± 1.8 vs 12.0 ± 0.3 mm Hg)(P < 0.001). The same was observed when we compared the e NOS(56.8 ± 3.7 vs 13.46 ± 2.8 pixels)(P < 0.001),VEGF(34.9 ± 4.7 vs 17.46 ± 2.6 pixels)(P < 0.05),and NTT(39.01 ± 4.0 vs 12.77 ± 2.3 pixels)(P < 0.05) expression by immunohistochemistry of the PPVL animals with the SO group. The expression of e NOS(0.39 ± 0.03 vs 0.25 ± 0.03 a.μ)(P < 0.01) and VEGF(0.38 ± 0.04 vs 0.26 ± 0.04 a.μ)(P < 0.01) were also evaluated by Western blot analysis,and we observed an increase of both proteins on PPVL animals. We also evaluated the DNA damage by comet assay,and observed an increase on damage index and damage frequency on those animals. NAC decreased portal pressure values in PPVL + NAC animals(16.46 ± 2 vs 29.8 ± 1.8 mm Hg)(P < 0.001) when compared to PPVL. The expression of e NOS(14.60 ± 4.1 vs 56.8 ± 3.7 pixels)(P < 0.001),VEGF(19.53 ± 3.2 vs 34.9 ± 4.7 pixels)(P < 0.05) and NTT(21.84 ± 0.7 vs 39.01 ± 4.0 pixels)(P < 0.05) evaluated by immunohistochemistry were also reduced in PPVL + NAC animals. Also,when evaluated by Western blot e NOS expression(0.32 ± 0.03 vs 0.39 ± 0.03 a.μ)(P < 0.05) and VEGF expression(0.31 ± 0.09 vs 0.38 ± 0.04 a.μ)(P < 0.01). Furthermore,NAC modulated DNA damage in PPVL + NAC animals.CONCLUSION: In view of these results,we believe NAC is able to protect the stomach from the alterations induced by the PPVL procedure.展开更多
Bleeding from esophageal varices is a life threatening complication of portal hypertension.Primary prevention of bleeding in patients at risk for a first bleeding episode is therefore a major goal.Medical prophylaxis ...Bleeding from esophageal varices is a life threatening complication of portal hypertension.Primary prevention of bleeding in patients at risk for a first bleeding episode is therefore a major goal.Medical prophylaxis consists of non-selective beta-blockers like propranolol or carvedilol.Variceal endoscopic band ligation is equally effective but procedure related morbidity is a drawback of the method.Therapy of acute bleeding is based on three strategies:vasopressor drugs like terlipressin,antibiotics and endoscopic therapy.In refractory bleeding,self-expandable stents offer an option for bridging to definite treatments like transjugular intrahepatic portosystemic shunt(TIPS).Treatment of bleeding from gastric varices depends on vasopressor drugs and on injection of varices with cyanoacrylate.Strategies for primary or secondary prevention are based on non-selective beta-blockers but data from large clinical trials is lacking.Therapy of refractory bleeding relies on shuntprocedures like TIPS.Bleeding from ectopic varices,portal hypertensive gastropathy and gastric antral vascular ectasia-syndrome is less common.Possible medical and endoscopic treatment options are discussed.展开更多
文摘AIM: To describe the pathophysiology, clinical presentation, natural history, and therapy of portal hypertensive gastropathy(PHG) based on a systematic literature review.METHODS: Computerized search of the literature was performed via Pub Med using the following medical subject headings or keywords: "portal" and "gastropathy"; or "portal" and "hypertensive"; or "congestive" and "gastropathy"; or "congestive" and "gastroenteropathy". The following criteria were applied for study inclusion: Publication in peer-reviewed journals, and publication since 1980. Articles were independently evaluated by each author and selected for inclusion by consensus after discussion based on the following criteria: Well-designed, prospective trials; recent studies; large study populations; and study emphasis on PHG. RESULTS: PHG is diagnosed by characteristic endoscopic findings of small polygonal areas of variable erythema surrounded by a pale, reticular border in a mosaic pattern in the gastric fundus/body in a patient with cirrhotic or non-cirrhotic portal hypertension. Histologic findings include capillary and venule dilatation, congestion, and tortuosity, without vascular fibrin thrombi or inflammatory cells in gastric submucosa. PHG is differentiated from gastric antral vascular ectasia by a different endoscopic appearance. The etiology of PHG is inadequately understood. Portal hypertension is necessary but insufficient to develop PHG because many patients have portal hypertension without PHG.PHG increases in frequency with more severe portal hypertension, advanced liver disease, longer liver disease duration, presence of esophageal varices, and endoscopic variceal obliteration. PHG pathogenesis is related to a hyperdynamic circulation, induced by portal hypertension, characterized by increased intrahepatic resistance to flow, increased splanchnic flow, increased total gastric flow, and most likely decreased gastric mucosal flow. Gastric mucosa in PHG shows increased susceptibility to gastrotoxic chemicals and poor wound healing. Nitrous oxide, free radicals, tumor necrosis factor-alpha, and glucagon may contribute to PHG development. Acute and chronic gastrointestinal bleeding are the only clinical complications. Bleeding is typically mild-to-moderate. Endoscopic therapy is rarely useful because the bleeding is typically diffuse. Acute bleeding is primarily treated with octreotide, often with concomitant proton pump inhibitor therapy, or secondarily treated with vasopressin or terlipressin. Nonselective β-adrenergic receptor antagonists, particularly propranolol, are used to prevent bleeding after an acute episode or for chronic bleeding. Iron deficiency anemia from chronic bleeding may require iron replacement therapy. Transjugular-intrahepaticportosystemic-shunt or liver transplantation is highly successful ultimate therapies because they reduce the underlying portal hypertension.CONCLUSION: PHG is important to recognize in patients with cirrhotic or non-cirrhotic portal hypertension because it can cause acute or chronic GI bleeding that often requires pharmacologic therapy.
基金Supported by CAPES-MEC-Brazil-Grant master’s thesis
文摘AIM: To analyze reliability among endoscopists in diagnosing portal hypertensive gastropathy (PHG) and to determine which criteria from the most utilized classifications are the most suitable. METHODS: From January to July 2009, in an academic quaternary referral center at Santa Casa of S o Paulo Endoscopy Service, Brazil, we performed this singlecenter prospective study. In this period, we included 100 patients, including 50 sequential patients who had portal hypertension of various etiologies; who were previously diagnosed based on clinical, laboratory and imaging exams; and who presented with esophageal varices. In addition, our study included 50 sequentialpatients who had dyspeptic symptoms and were referred for upper digestive endoscopy without portal hypertension. All subjects underwent upper digestive endoscopy, and the images of the exam were digitally recorded. Five endoscopists with more than 15 years of experience answered an electronic questionnaire, which included endoscopic criteria from the 3 most commonly used Portal Hypertensive Gastropathy classifications (McCormack, NIEC and Baveno) and the presence of elevated or flat antral erosive gastritis. All five endosco- pists were blinded to the patients' clinical information, and all images of varices were deliberately excluded for the analysis. RESULTS: The three most common etiologies of portal hypertension were schistosomiasis (36%), alcoholic cirrhosis (20%) and viral cirrhosis (14%). Of the 50 patients with portal hypertension, 84% were Child A, 12% were Child B, 4% were Child C, 64% exhibited previous variceal bleeding and 66% were previously endoscopic treated. The endoscopic parameters, presence or absence of mosaic-like pattern, red point lesions and cherry-red spots were associated with high inter-observer reliability and high specificity for diagnosing Portal Hypertensive Gastropathy. Sensitivity, specificity and reliability for the diagnosis of PHG (%) were as follows: mosaic-like pattern (100; 92.21; High); fine pink speckling (56; 76.62; Unsatisfactory); superficial reddening (69.57; 66.23; Unsatisfactory); red-point lesions (47.83; 90.91; High); cherry-red spots (39.13; 96.10; High); isolated red marks (43.48; 88.31; High); and confluent red marks (21.74; 100; Unsatisfactory). Antral elevated erosive gastritis exhibited high reliability and high specificity with respect to the presence of portal hypertension (92%) and the diagnosis of portal hypertensive gastropathy (88.31%). CONCLUSION: The most suitable endoscopic criteria for the diagnosis of PHG were mosaic-like pattern, redpoint lesions and cherry-red spots with no subdivisions,which were associated with a high rate of inter-observer reliability.
文摘AIM:To investigate any protective effect of early propranolol administration in the development of portal hypertensive gastropathy in cirrhotic rats. METHODS:For the development of liver cirrhosis and portal hypertensive gastropathy,60 rats underwent ligation of the left adrenal vein and complete devascularization of the left renal vein,followed by phenobarbital and carbon tetrachloride(CCl4) administration.After two weeks of CCl4 administration, the rats were randomly separated into two groups.In group A,propranolol was continuously administered intragastrically throughout the study,whereas in group B normal saline(placebo)was administered instead. Hemodynamic studies and vascular morphometric analysis of gastric sections were performed after complete induction of cirrhosis. RESULTS:Vascular morphometric studies showed higher numbers of vessels in all mucosal layers in the control group.Statistical analysis revealed a significantly higher total vascular surface in the control group compared to the propranolol group,but with no statistically significant difference between the mean vascular surfaces between the groups.Our study clearly shows that the increased mucosal blood flow is manifested by a marked increase of vessel count. CONCLUSION:Early propranolol's administration in portal hypertensive cirrhotic rats seems to prevent intense gastric vascular congestion that characterizes portal hypertensive gastropathy.
基金supported by grants from the National Natu-ral Science Foundation of China(81572437,81470791,81376597)Health Scientific Research Program of Gansu Province(GSWSKY2017-09)
文摘To the Editor:H. pylori lives in the gastric epithelial cells, sometimes in gastric glands.Whetherornottheproliferationandbiologicalbehavior of H. pylori can be influenced by the status of the gastric mucosa is still unknown. Portal hypertensive gastropathy (PHG) is a blood drainage obstructive disease. In this pathologic environment, gastric mucosa may be further impaired when patients are infected with H. pylori. The role of H. pylori in the pathogenesis of PHG and
基金supported by a Natural Science Foundation of Hainan Province Grant(No.80599)
文摘Objective:To study the role and the mechanism of endotoxin in the pathogenesis of gastric mucosa during portal vein hypertension gastrography(PHG) in the rats with cirrhosis.Methods: Rat model for PHG was established by injection of tetrachloride.The animals were injected with endotoxin i.p.at 3 mg/kg and endotoxin antagonist BPI21 i.v.at 2.0 mg/kg.The plasma level of endotoxin as well as the gastric mucosal level of tumor necrosis factor alpha(TNF-α) was measured with azobenzene and ELISA respectively.Furthermore,the pathological changes of the gastric mucosa were studied with HE stainning.Results:In rats with PHG,increased endotoxin and TNF-αas well as the gastric pathological lesion were observed.Injection of endotoxin remarkably increased plasma level of endotoxin as well as the gastric mucosal level of tumor necrosis TNF-αand induced more serious gastric lesion.Animals injected with endotoxin antagonist BPI21 showed improved gastric mucosal lesion,accompanied by the declining TNF-αlevel.Conclusions:Our results suggestes that endotoxin may play a pathogenetic role in PHG by inducing the expression of TNF-α.
文摘BACKGROUND Accurate detection of gastric antral vascular ectasia(GAVE)is critical for proper management of cirrhosis-related gastrointestinal bleeding.However,endoscopic diagnosis of GAVE can be challenging when GAVE overlaps with severe portal hypertensive gastropathy(PHG).AIM To determine the added diagnostic value of virtual chromoendoscopy to high definition white light for real-time endoscopic diagnosis of GAVE and PHG.METHODS We developed an I-scan virtual chromoendoscopy criteria for diagnosis of GAVE and PHG.We tested our criteria in a cross-sectional cohort of cirrhotic adults with GAVE and PHG when high-definition white light endoscopy(HDWLE)diagnosis was in doubt.We then compared the accuracy of I-scan vs HDWLE alone to histology.RESULTS Twenty-three patients were included in this study(65.2%Caucasians and 60.9%males).Chronic hepatitis C was the predominant cause of cirrhosis(43.5%)and seven adults(30.4%)had confirmed GAVE on histology.I-scan had higher sensitivity(100%vs 85.7%)and specificity(75%vs 62.5%)in diagnosing GAVE compared to HDWLE.This translates into a higher,albeit not statistically significant,accuracy of I-scan in detecting GAVE compared to HDWLE alone(82%vs 70%).I-scan was less likely to lead to an accurate diagnosis of GAVE in patients on dialysis(P<0.05)and in patients with elevated creatinine(P<0.05).Iscan had similar accuracy to HDWLE in detecting PHG.CONCLUSION This pilot work supports that virtual chromoendoscopy may obviate the need for biopsies when the presence of GAVE is in doubt.Larger studies are needed to assess the impact of virtual chromoendoscopy on success of endoscopic therapy for GAVE.
基金Supported by Brazilian agencies Coordena??o de Aperfei?oamento de Pessoal de Nível Superior,Conselho Nacional de Desenvolvimento Científico e TecnológicoFundo de IncentivoàPesquisa e Eventos-Hospital de Clínicas of Porto Alegre(FIPE project no11-0293)+3 种基金the Laboratory of Experimental Hepatology and Gastroenterology(HCPA/UFRGS)Universidade Federal doRio Grande do Sulthe Oxidative Stress and Antioxidants LaboratoryUniversidade Luterana do Brasil
文摘AIM: To evaluate the antioxidant effect of N-acetylcysteine(NAC) on the stomach of rats with portal hypertension.METHODS: Twenty-four male Wistar rats weighing ± 250 g were divided into four experimental groups(n =6 each): Sham-operated(SO),SO + NAC,partial portal vein ligation(PPVL),and PPVL + NAC. Treatment with NAC in a dose of 10 mg/kg(i.p.) diluted in 0.6 m L of saline solution was administered daily for 7 d starting 8 d after the surgery. Animals from the PPVL and SO group received saline solution(0.6 m L) for the same period of time as the PPVL + NAC and SO + NAC group. On the 15 th day the animals were anesthetized and we evaluated portal pressure by cannulating mesenteric artery. After,we removed the stomach for further analysis. We performed immunohistochemical analysis for endothelial nitric oxide synthase(e NOS),vascular endothelial growth factor(VEGF),and nitrotirosine(NTT) proteins in stomach. We also evaluated e NOS and VEGF by Western blot analysis and assessed DNA damage in blood samples by the comet assay.RESULTS: The portal hypertension group exhibited increases in portal pressure when compared to SO group(29.8 ± 1.8 vs 12.0 ± 0.3 mm Hg)(P < 0.001). The same was observed when we compared the e NOS(56.8 ± 3.7 vs 13.46 ± 2.8 pixels)(P < 0.001),VEGF(34.9 ± 4.7 vs 17.46 ± 2.6 pixels)(P < 0.05),and NTT(39.01 ± 4.0 vs 12.77 ± 2.3 pixels)(P < 0.05) expression by immunohistochemistry of the PPVL animals with the SO group. The expression of e NOS(0.39 ± 0.03 vs 0.25 ± 0.03 a.μ)(P < 0.01) and VEGF(0.38 ± 0.04 vs 0.26 ± 0.04 a.μ)(P < 0.01) were also evaluated by Western blot analysis,and we observed an increase of both proteins on PPVL animals. We also evaluated the DNA damage by comet assay,and observed an increase on damage index and damage frequency on those animals. NAC decreased portal pressure values in PPVL + NAC animals(16.46 ± 2 vs 29.8 ± 1.8 mm Hg)(P < 0.001) when compared to PPVL. The expression of e NOS(14.60 ± 4.1 vs 56.8 ± 3.7 pixels)(P < 0.001),VEGF(19.53 ± 3.2 vs 34.9 ± 4.7 pixels)(P < 0.05) and NTT(21.84 ± 0.7 vs 39.01 ± 4.0 pixels)(P < 0.05) evaluated by immunohistochemistry were also reduced in PPVL + NAC animals. Also,when evaluated by Western blot e NOS expression(0.32 ± 0.03 vs 0.39 ± 0.03 a.μ)(P < 0.05) and VEGF expression(0.31 ± 0.09 vs 0.38 ± 0.04 a.μ)(P < 0.01). Furthermore,NAC modulated DNA damage in PPVL + NAC animals.CONCLUSION: In view of these results,we believe NAC is able to protect the stomach from the alterations induced by the PPVL procedure.
文摘Bleeding from esophageal varices is a life threatening complication of portal hypertension.Primary prevention of bleeding in patients at risk for a first bleeding episode is therefore a major goal.Medical prophylaxis consists of non-selective beta-blockers like propranolol or carvedilol.Variceal endoscopic band ligation is equally effective but procedure related morbidity is a drawback of the method.Therapy of acute bleeding is based on three strategies:vasopressor drugs like terlipressin,antibiotics and endoscopic therapy.In refractory bleeding,self-expandable stents offer an option for bridging to definite treatments like transjugular intrahepatic portosystemic shunt(TIPS).Treatment of bleeding from gastric varices depends on vasopressor drugs and on injection of varices with cyanoacrylate.Strategies for primary or secondary prevention are based on non-selective beta-blockers but data from large clinical trials is lacking.Therapy of refractory bleeding relies on shuntprocedures like TIPS.Bleeding from ectopic varices,portal hypertensive gastropathy and gastric antral vascular ectasia-syndrome is less common.Possible medical and endoscopic treatment options are discussed.