Hemostatic defects in experimental obstructive jaundice

To elucidate the etiology of hemostatic abnormalities in cases of obstructive jaundice, we occluded the bile duct of rats for one week and found that the moderately jaundiced rats exhibited a marked reduction in the value of Hepaplastin test® and Thrombotest® with minimum histological changes in liver. All other coagulation and fibrinolysis profiles were within normal limits. These findings exclude the occurrence of a hypercoagulable state or hypofibrinolytic state in the jaundiced rats due to bile duct occlusion. Similar results were obtained in rats with tube choledochostomy. The abnormalities were almost completely prevented by the daily parenteral administration of vitamin K. These observations suggest that malabsorption of vitamin K may be the sole etiologic factor producing hemostatic defects in case of uncomplicated obstructive jaundice.     

Vascular reactivity in reversible experimental obstructive jaundice

We studied the effect of jaundice on in vitro vascular reactivity to cumulative doses of norepinephrine (NE) by measuring the maximal response (Rmax) and the concentration of NE required to cause a 50% response (ED50) of isolated vascular smooth muscle. For this we prepared helically cut strips of thoracic aorta from bile duct ligated (BDL) rats at 1, 3, 6, 14, and 28 days postligation and compared them with those of nonoperated and sham-operated controls. From 1 to 6 days post-BDL, changes in liver blood chemistry and liver histology indicated cholestasis with necrosis. By 14 days, the tests for liver function and histology indicated a return to normal liver function and histology. In nonoperated controls, mean Rmax increased significantly from 883 +/- 67 mg of tension to 1220 +/- 68 mg of tension (P less than 0.0025) from 0 to 28 days, whereas ED50 remained unchanged. In sham-operated controls and BDL rats, an age-dependent increase in Rmax was also observed. However, in the sham groups, ED50 tended to decrease compared with nonoperated controls, indicating a surgically induced "sensitization" phenomenon of the vascular smooth muscle. In contrast, this was not seen in BDL rats since in these groups, the ED50 remained unchanged and significantly higher than in the sham groups, in both the jaundiced (1-6 days) and nonjaundiced (14-28 days) period. Furthermore, these changes occurred in the absence of any alteration in portal pressure. These changes may be important in understanding the mechanism of hypotension and shock in postoperative patients with obstructive jaundice even after the jaundice has been relieved.     

Reversibility of leukocyte dysfunction in rats with obstructive jaundice

BACKGROUND: The role of leukocytes in obstructive jaundice is obscure and the effect of relieving cholestasis on leukocyte function is unclear. We postulated that cholestasis affects systemic polymorphonuclear leukocyte function by deranging phagocytosis and hydrogen peroxide release and the leukocyte dysfunction is reversible by internal and external biliary drainage. MATERIALS AND METHODS: Sixty male Sprague Dawley rats were randomly assigned to four groups: obstructive jaundice (OJ), sham operation (SH), OJ with internal drainage (ID), and OJ with external drainage (ED). The phagocytic functions of neutrophils and monocytes in whole blood were measured with flow cytometry using fluorescent microspheres. Intracellular hydrogen peroxide production by leukocytes was assessed with flow cytometry using dihydrorhodamine-123 as probes. RESULTS: Leukocyte count and percentage of monocytes in rats with OJ was significantly increased compared with SH rats (P < 0.001). These elevations could be reversed by both ID and ED method (P < 0.001). The phagocytic function of neutrophils and monocytes was significantly depressed in OJ rats compared with that in SH rats (P < 0.001). After relief of the OJ, the suppressed phagocytic function of neutrophils and monocytes was completely improved in ID rats (ID versus OJ, P < 0.001), but only partially reversed in ED rats. The hydrogen peroxide production by monocytes and lymphocytes was significantly increased in OJ rats (P < 0.05). ID reversed the increased hydrogen peroxide generation (P < 0.05), but ED only partially did. CONCLUSIONS: In our rodent model of biliary obstruction, deranged phagocytosis, and hydrogen peroxide generation by leukocytes was found. Internal drainage is superior to external drainage for reversal of the distorted leukocyte function.     

Peritoneal dialysis in obstructive jaundice: an experimental study

Rats were subjected to common bile duct ligation, after which intermittent peritoneal dialysis with a buffered solution containing rat plasma proteins was carried out in an attempt to reduce plasma bilirubin levels. Plasma bilirubin increased significantly (P less than 0.01) on the seventh day and was still rising 12 days after ligation of the common bile duct. Dialysis was performed during the second postoperative week. Provided that rat plasma protein was present in the dialysing fluid, dialysis significantly reduced (P less than 0.01) the levels of total plasma bilirubin, conjugated bilirubin and serum GPT in the experimental animals.     

阻塞性黄疸伴肝功能不全患者顺式阿曲库铵的肌松效应

目的 观察单次静脉注射顺式阿曲席铵在阻塞性黄疸伴有肝功能不全患者的肌松效应.方法 30例择期行上腹部手术的患者均分为阻塞性黄疸伴有肝功能不全(Child-Pugh B级)组(G组)和肝功能正常组(C组).麻醉诱导均采用丙泊酚3 μg/ml、雷米芬太尼3～6 ng/ml、顺式阿曲库铵0.15 mg/kg后气管插管,评估插管条件,记录顺式阿曲库铵的肌松作用指标.结果 G组肌松起效时间较C组明显延长(P＜0.01);两组最大阻滞程度、插管条件、最大效应持续时间、单个颤搐刺激反应强度(T1)10%恢复时间、T125%恢复时间、T175%恢复时间、TOF比(T4/T1)70%恢复时间、恢复指数差异均无统计学意义.结论 阻塞性黄疸伴有肝功能小全患者单次静注顺式阿曲库铵后肌松起效时间明显长于肝功能正常者.     

Hepatic recovery after biliary decompression of experimental obstructive jaundice

Obstructive jaundice was produced in 11 dogs by common bile duct ligation for 4 weeks, then biliary decompression was performed by bilioenteric anastomosis. Animals were regularly studied over the 2 months after decompression by the following methods: (1) serum biochemistry was monitored; (2) light microscopic changes in serial liver biopsies were graded; (3) the respiratory characteristics of isolated hepatic mitochondria, obtained by open liver biopsy, were studied using an oxygen micro-electrode system; (4) in vivo handling of an hepatobiliary imaging agent (diisopropyl iminodiacetic acid) was studied by dynamic liver scintiscanning. None of these liver assessments were normalized after 7 to 10 days of biliary decompression. Our study suggests that biliary decompression of patients with extrahepatic biliary obstruction requires long periods of time to enable major recovery of the abnormal liver function induced by biliary obstruction.     

Histological changes in the brain due to experimental obstructive jaundice

Histopathological changes and energy charge of the canine brain under the experimental obstructive jaundice were investigated. The common bile duct was ligated in group A (n = 25), and biliary decompression was carried out in group B after the duration of the obstructive jaundice, (n = 11). The results were as follows. 1) Simple atrophy, pyknosis, neuronophagia, and ghost cell were observed in nerve cells. 2) The changes of nerve cells appeared after 7 days of the obstructive jaundice at the basal ganglia, putamen and red nucleus. After 13 days of the obstructive jaundice, they spread widely to the thalamus, cerebral cortex and substantia nigra. 3) According to decreasing ratio of serum bilirubin concentration, B group was classified into 4 groups. Poorly decompressed groups III and IV showed severe histological changes than fairy decompressed groups I and II. 4) Energy charge of the substantia nigra after 7 days of the obstructive jaundice decreased to 0.65 comparing with 0.77 of control group. The results indicate that obstructive jaundice should be decompressed as early as possible.     

Contribution of portal systemic shunt to Kupffer cell dysfunction in obstructive jaundice

Previous animal models of biliary tract obstruction have shown that hepatic phagocytic activity is impaired secondary to Kupffer cell dysfunction. Biliary tract obstruction leads to portal hypertension and an associated portal systemic shunt. Forty-eight Sprague-Dawley rats were studied to determine the contribution of portal systemic shunt to Kupffer cell dysfunction after 21 days of obstructive jaundice or sham operation. Liver uptake of radiolabeled Escherichia coli decreased from 76.1 +/- 1.4% (sham) to 63.1 +/- 6.1% in the common duct ligation (CDL) rats (P less than 0.05); lung uptake increased from 4.0 +/- 0.6% (sham) to 20.2 +/- 4.5 (CDL) (P less than 0.05). Portal systemic shunt, determined using radioactive microspheres, increased from 2.0 +/- 1.0% (sham) to 46.6 +/- 13.1% (CDL), P less than 0.05. Although a significant portal systemic shunt does exist in this 21-day model of obstructive jaundice, it does not appear to be the only mechanism underlying Kupffer cell dysfunction.     

Development and reversal of endotoxemia and endotoxin-related death in obstructive jaundice

Gut-derived endotoxemia has been implicated in postoperative complications in patients with jaundice. It is thought that absence of bile in the gut predisposes to portal absorption of endotoxin and endotoxemia is reversed by oral bile salt replacement or internal biliary drainage and return of bile to the gut, but not by external drainage. We believe that the importance of gastrointestinal bile flow has been overestimated and biliary obstruction and the integrity of hepatocyte and Kupffer cell function are more important in the development and reversal of endotoxemia. In experiment 1, serum endotoxin concentrations were measured in control rats (n = 10) after choledochovesical fistula (n = 15) and bile duct ligation (n = 15) and after relief of biliary obstruction by internal drainage (choledochoduodenostomy; n = 8) and sterile external drainage (choledochovesical fistula; n = 8), with a quantitative limulus assay. In experiment 2, mortality rates were measured in similar groups 48 hours after administration of oral endotoxin (5 mg/100 gm) and intravenous lead acetate (5 mg/100 gm). Bilirubin levels were elevated in bile duct ligation (192 +/- 13 mumols/L) compared with control animals and those with choledochovesical fistula, internal drainage, and external drainage (10.6 +/- 1.5 mumols/L). In experiment 1, significant portal endotoxemia and systemic endotoxemia occurred in bile duct ligation (portal, 130.4 +/- 12.9 pg/ml; systemic, 91.8 +/- 11.0 pg/ml) but not in choledochovesical fistula (portal, 49.3 +/- 17.1 pg/ml; systemic, 27.2 +/- 11.5 pg/ml). Relief of obstruction by both internal and external drainage reversed endotoxemia. In experiment 2, significant death occurred in bile duct ligation (13 of 15) but not in choledochovesical fistula (3 of 15), and relief of obstruction by both internal and external drainage prevented death. These results confirm that biliary obstruction is a more important factor than is gastrointestinal bile flow in the development and reversal of endotoxemia.     

T lymphocyte participation in antibody-induced experimental glomerulonephritis

Macrophage accumulation is a feature of some aggressive forms of human and experimental glomerulonephritis (GN). Both antibody Fc components and T cells may cause macrophage accumulation; however, there has been no previous demonstration of T cells at the site of injury in GN, although some indirect evidence of their possible participation has been reported. Specific monoclonal anti-rat T lymphocyte antibodies W3/13, W3/25, and Ox8 were used to demonstrate T cells within the glomeruli of rats with an augmented autologous anti-GBM GN, by indirect immunofluorescence. The injury in this model has been shown to be mediated by macrophages. The T cell infiltrate consisted mainly of T helper cells, was maximal 24 hr after induction of the disease and clearly preceded the peak influx of macrophages and glomerular damage. Suppression of T cell function using cyclosporin prevented T cell accumulation and the subsequent macrophage-induced injury. Glomerular T cells were not seen in passively induced GN. These studies support a role for cell-mediated immunity in attracting macrophages and initiating injury in experimental anti-GBM antibody-induced GN.     

梗阻性黄疸围手术期肾水通道蛋白1表达变化的实验研究

目的 探讨大鼠胆道梗阻解除后肾脏近曲小管上皮细胞形态学检测及水通道蛋白1表达的变化.方法 30只大鼠随机分为二组,分别为假手术组10只、梗阻性黄疸组20只.梗阻性黄疸组20只大鼠全身麻醉后建立梗阻性黄疸动物模型;假手术组10只大鼠行假手术.7 d后再次全麻解除胆道梗阻,而假手术组再次行假手术.并将各组动物随机均分为立即取材组和24 h后取材组,分别立即处死取材或24 h后处死取材.将静脉血离心后血清冻存检测肝功能、肾功能;部分肾脏标本冻存,Western印迹法半定量检测水通道蛋白1(aquaporinl,aqp1)表达;部分肾脏固定后光镜检测.结果 解除梗阻早期鼠血清胆红素水平下降,同时血BUN及Cr未见明显改变.通过Western印迹对肾aqp1表达测定发现:梗阻性黄疸组aqp1表达较对照组明显下降,解除梗阻后梗黄组aqp1表达增强.结论 胆道梗阻会造成肾脏近曲小管上皮细胞结构损伤,同时下调aqp1表达.解除梗阻后aqp1表达增强.     

Multivariate analysis of factors associated with renal dysfunction in patients with obstructive jaundice

BACKGROUND: The aim was to evaluate the factors determining preoperative renal dysfunction in patients with obstructive jaundice. METHODS: In a prospective cross-sectional observational study, 63 patients, 27 with benign and 36 with malignant obstructive jaundice, were investigated at admission and compared with 25 healthy control subjects. Variables analysed included extracellular body water (ECW) compartment, plasma levels of aldosterone, renin, atrial natriuretic peptide, vasopressin, nitric oxide, endothelin (ET) 1 and prostaglandin E2 (PGE2), urinary nitric oxide and PGE2, serum albumin and renal function. RESULTS: The metabolic profile of obstructive jaundice was characterized by a depletion of the ECW (P = 0.004), and increased plasma levels of atrial natriuretic peptide (P < 0.001), ET-1 (P = 0.044), vasopressin (P = 0.017), aldosterone (P = 0.005) and renin (P = 0.001). Increased plasma (P < 0.001) and urinary (P = 0.001) PGE2 levels were also found. Fifty-four per cent of patients had a creatinine clearance of less than 70 ml/min. In multivariate analysis, serum bilirubin, renin, ET-1, PGE2, decreased urinary sodium excretion and age were identified as predictors of renal dysfunction. CONCLUSIONS: Renal dysfunction in patients with obstructive jaundice was associated with the degree of biliary obstruction, age of the patient and reduced urinary sodium excretion. These alterations were closely related to derangements in sodium- and water-regulating hormones.     

The ultrastructural research of liver in experimental obstructive jaundice and effect of honey

BACKGROUND: To examine the effects of honey on oxidative stress and apoptosis in experimental obstructive jaundice model. METHOD: Thirty rats were divided into 3 groups: group I, sham-operated; group II, ligation and division of the common bile duct (BDL); group III, BDL followed by oral supplementation of honey 10 g/kg/d. Liver samples were examined under light microscope and transmission electron microscope. Hepatocyte apoptosis was quantitated using the terminal deoxy-nucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. Plasma and blood malondialdehyde (MDA) and glutation activities were measured for determining the oxidative stress. RESULTS: The liver levels of MDA and GSH were significantly different between the honey and BDL groups (P = .006 and .001, respectively). However, there was no significant difference between the plasma MDA and GSH levels of these groups (P > .05). In group III, significant reductions in the size of enlarged hepatocytes and the edema were demonstrated. The dilatation of the bile canaliculi dramatically turned to original dimention. By TUNEL assay, it was shown that administration of honey decreased the number of apoptotic cells. CONCLUSIONS: In the present study, we found that honey diminished the negative effects of BDL on the hepatic ultrastructure. We conclude that this effect might be due to its antioxidant and anti-inflammatory activities.     

内毒素引起阻塞性黄疸大鼠肾功能障碍的机制

目的 探讨阻塞性黄疸(obstructive jaundice,OJ)时内毒素引起肾功能障碍的机制.方法 SD大鼠60只,胆总管结扎后,分5 d(B1),10 d(B2),15 d(B3)三组,每组各10只,同时建立相应对照组(A1,A2,A3),另30只胆总管结扎后分3组(SHUD,LAC,NS),每组各10只,分别用2 ml舒胆合剂、乳果糖液、生理盐水灌胃,连用9 d.观察内毒素、血和肾组织中内皮素(endothelin,ET)、一氧化氮(nitric oxide,NO)的含量、一氧化氮合酶(nitric oxide synthase,NOS)活性及肝、肾功能的变化.结果 血内毒素与血、肾组织ET含量,ET/NO比值呈显著正相关(P＜0.05,r=0.630,0.438,0.496,0.453),与肌肝清除率(creatinine clearance,Ccr)和肾皮质血流量(renal cortical blood flow,BCBF)呈显著负相关(P＜0.05,r=-0.600,-0.410).血、肾组织ET/NO比值与Ccr,RCBF呈显著负相关(P＜0.05,r=-0.449,-0.558,-0.626,-0.731).血和肾组织内NO水平与内毒素水平呈负相关(P＜0.05,r=-0.518,-0.441),与Ccr、RCBF呈正相关(P＜0.05,r=0.422,0.496,0.400,0.659).SHUD组与LAC血内毒素、ET水平组明显降低,血和肾组织NO,NOS活性以及Ccr,RCBF较NS组明显升高.结论 OJ时内毒素可通过刺激ET的释放,提高ET/NO比值,使肾内缩血管因子与扩血管因子比例失调而损伤肾功能.