Objective To compare the vasoconstrictive eff ects of 9 mediators on fresh and incubated mesenteric arteries of rats. Methods The superior mesenteric artery of rat was removed and t he endothelium was denuded. The v...Objective To compare the vasoconstrictive eff ects of 9 mediators on fresh and incubated mesenteric arteries of rats. Methods The superior mesenteric artery of rat was removed and t he endothelium was denuded. The vessels were cut into 1 mm long cylindrical segm ents and subjected to organ culture for 24 hours. Fresh or incubated segments we re immersed into tissue baths and the concentration-response curves were obtain ed by cumulative administration of the vasoconstrictors. Results In fresh mesenteric artery, endothelin-1 (ET-1), 5-h ydroxytryptamine (5-HT), noradrenaline (NA), 5-carboxamidotryptamine (5-CT), and angiotensinⅡ (AngⅡ) induced potent and sustained constrictions in a concen tration-dependent manner. The contraction induced by sarafotoxin 6c (S6c) was w eak, while bradykinin (BK), des-Arg-bradykinin (DA-BK), and human urotensinⅡ (hUT-II) showed no detectable contraction. The concentraion-response curves i n order of slopes was ET-1, NA, 5-HT, 5-CT, and AngⅡ. The order of the maxim um contractions was ET-1>NA=5-HT=5-CT>AngⅡ>S6c. After organ culture, the con centration-response curves induced by S6c, NA, and 5-HT were significantly inc reased, while that induced by AngⅡ was decreased as comparing to fresh arteries . BK contracted the artery only weakly. Conclusion Organ culture changed the phenotypes towards an increased efficacy of NA, 5-HT, S6c, and a reduced efficacy of AngⅡ, which is in accordance with the results o f pharmacological characterization in some human vascular disease.展开更多
Spontaneous bacterial peritonitis(SBP),refractory ascites,hepatorenal syndrome(HRS),hyponatremia and hepatic encephalopathy are complicationswhich frequently happen during a clinical course of decompensated cirrhosis....Spontaneous bacterial peritonitis(SBP),refractory ascites,hepatorenal syndrome(HRS),hyponatremia and hepatic encephalopathy are complicationswhich frequently happen during a clinical course of decompensated cirrhosis.Splanchnic and peripheral vasodilatation,increased intrarenal vasoconstriction and impaired cardiac responsive function are pathological changes causing systemic and hemodynamic derangement.Extreme renal vasoconstriction leads to severe reduction of renal blood flow and glomerular filtration rate,which finally evolves into the clinical feature of HRS.Clinical manifestations of type 1 and type 2 HRS come to medical attention differently.Patients with type1 HRS present as acute kidney injury whereas those with type 2 HRS will have refractory ascites as the leading problem.Prompt diagnosis of type 1 HRS can halt the progression of HRS to acute tubular necrosis if the combined treatment of albumin infusion and vasoconstrictors is started timely.HRS reversal was seen in 34%-60%of patients,followed with decreasing mortality.Baseline serum levels of creatinine less than5 mg/dL,bilirubin less than 10 mg/dL,and increased mean arterial pressure of over 5 mmHg by day 3 of the combined treatment of vasoconstrictor and albumin are the predictors of good response.Type 1 HRS can be prevented in some conditions such as albumin infusion in SBP,prophylactic antibiotics for upper gastrointestinal hemorrhage,albumin replacement after large volume paracentesis in cirrhotic patients with massive ascites.The benefit of albumin infusion in infection with primary source other than SBP requires more studies.展开更多
文摘Objective To compare the vasoconstrictive eff ects of 9 mediators on fresh and incubated mesenteric arteries of rats. Methods The superior mesenteric artery of rat was removed and t he endothelium was denuded. The vessels were cut into 1 mm long cylindrical segm ents and subjected to organ culture for 24 hours. Fresh or incubated segments we re immersed into tissue baths and the concentration-response curves were obtain ed by cumulative administration of the vasoconstrictors. Results In fresh mesenteric artery, endothelin-1 (ET-1), 5-h ydroxytryptamine (5-HT), noradrenaline (NA), 5-carboxamidotryptamine (5-CT), and angiotensinⅡ (AngⅡ) induced potent and sustained constrictions in a concen tration-dependent manner. The contraction induced by sarafotoxin 6c (S6c) was w eak, while bradykinin (BK), des-Arg-bradykinin (DA-BK), and human urotensinⅡ (hUT-II) showed no detectable contraction. The concentraion-response curves i n order of slopes was ET-1, NA, 5-HT, 5-CT, and AngⅡ. The order of the maxim um contractions was ET-1>NA=5-HT=5-CT>AngⅡ>S6c. After organ culture, the con centration-response curves induced by S6c, NA, and 5-HT were significantly inc reased, while that induced by AngⅡ was decreased as comparing to fresh arteries . BK contracted the artery only weakly. Conclusion Organ culture changed the phenotypes towards an increased efficacy of NA, 5-HT, S6c, and a reduced efficacy of AngⅡ, which is in accordance with the results o f pharmacological characterization in some human vascular disease.
文摘Spontaneous bacterial peritonitis(SBP),refractory ascites,hepatorenal syndrome(HRS),hyponatremia and hepatic encephalopathy are complicationswhich frequently happen during a clinical course of decompensated cirrhosis.Splanchnic and peripheral vasodilatation,increased intrarenal vasoconstriction and impaired cardiac responsive function are pathological changes causing systemic and hemodynamic derangement.Extreme renal vasoconstriction leads to severe reduction of renal blood flow and glomerular filtration rate,which finally evolves into the clinical feature of HRS.Clinical manifestations of type 1 and type 2 HRS come to medical attention differently.Patients with type1 HRS present as acute kidney injury whereas those with type 2 HRS will have refractory ascites as the leading problem.Prompt diagnosis of type 1 HRS can halt the progression of HRS to acute tubular necrosis if the combined treatment of albumin infusion and vasoconstrictors is started timely.HRS reversal was seen in 34%-60%of patients,followed with decreasing mortality.Baseline serum levels of creatinine less than5 mg/dL,bilirubin less than 10 mg/dL,and increased mean arterial pressure of over 5 mmHg by day 3 of the combined treatment of vasoconstrictor and albumin are the predictors of good response.Type 1 HRS can be prevented in some conditions such as albumin infusion in SBP,prophylactic antibiotics for upper gastrointestinal hemorrhage,albumin replacement after large volume paracentesis in cirrhotic patients with massive ascites.The benefit of albumin infusion in infection with primary source other than SBP requires more studies.
