Artemisia capillaris Thunb. Polysaccharide alleviates cholestatic liver injury through gut microbiota modulation and Nrf2 signaling pathway activation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

According to traditional Chinese medicine (TCM) theory, cholestasis belongs to category of jaundice. Artemisia capillaris Thunb. has been widely used for the treatment of jaundice in TCM. The polysaccharides are the one of main active components of the herb, but its effects on cholestasis remain unclear.

AIM OF THE STUDY

To investigate the protective effect and mechanism of Artemisia capillaris Thunb. polysaccharide (APS) on cholestasis and liver injury.

MATERIALS AND METHODS

The amelioration of APS on cholestasis was evaluated in an alpha-naphthyl isothiocyanate (ANIT)-induced mice model. Then nuclear Nrf2 knockout mice, mass spectrometry, 16s rDNA sequencing, metabolomics, and molecular biotechnology methods were used to elucidate the associated mechanisms of APS against cholestatic liver injury.

RESULTS

Treatment with low and high doses of APS markedly decreased cholestatic liver injury of mice. Mechanistically, APS promoted nuclear translocation of hepatic nuclear factor erythroid 2-related factor (Nrf2), upregulated downstream bile acid (BA) efflux transporters and detoxifying enzymes expression, improved BA homeostasis, and attenuated oxidative liver injury; however, these effects were annulled in Nrf2 knock-out mice. Furthermore, APS ameliorated the microbiota dysbiosis of cholestatic mice and selectively increased short-chain fatty acid (SCFA)-producing bacteria growth. Fecal microbiota transplantation of APS also promoted hepatic Nrf2 activation, increased BA efflux transporters and detoxifying enzymes expression, ameliorated intrahepatic BA accumulation and cholestatic liver injury. Non-targeted metabolomics and in vitro microbiota culture confirmed that APS significantly increased the production of a microbiota-derived SCFA (butyric acid), which is also able to upregulate Nrf2 expression.

CONCLUSIONS

These findings indicate that APS can ameliorate cholestasis by modulating gut microbiota and activating the Nrf2 pathway, representing a novel therapeutic approach for cholestatic liver disease.

Identifying hepatoprotective mechanism and effective components of Yinchenzhufu decoction in chronic cholestatic liver injury using a comprehensive strategy based on metabolomics, molecular biology, pharmacokinetics, and cytology

ETHNOPHARMACOLOGICAL RELEVANCE

In Traditional Chinese Medicine (TCM), cholestasis liver disease belongs to jaundice. Yinchenzhufu decoction (YCZFD) is a classic formula used for treating jaundice.

AIM OF THE STUDY

This study was aimed to investigate the potential mechanism and effective components of YCZFD in chronic cholestatic liver injury (CCLI).

MATERIALS AND METHODS

A chronic cholestatic mouse model induced by 3, 5-diethoxycarbonyl-1, 4-dihydroxychollidine was used to investigate the effect of YCZFD. Then, metabolomics was used to investigate the metabolites influenced by YCZFD. Serum and liver bile acid (BA) levels were measured using liquid chromatography coupled with triple quadruple mass spectrometry (LC-MS/MS), and the gene and protein expressions of BA transporters and metabolic enzymes were detected. Additionally, the pharmacokinetics of multiple components of YCZFD was explored to clarify the potential effective components. The effects of absorbed components of YCZFD on BA metabolism and transporter function, inflammation, and farnesoid X receptor (FXR) and pregnane X receptor (PXR) activation were analyzed using sandwich cultured rat hepatocytes, AML12 cells, and dual-luciferase receptor systems, respectively.

RESULTS

YCZFD decreased the liver damage in chronic cholestatic mice. Serum metabolomics results indicated that the main pathways influenced by YCZFD involved primary BA biosynthesis and arachidonic acid metabolism. YCZFD upregulated the expression of FXR, PXR, and BA efflux transporters and the metabolic enzymes of liver tissues, promoting BA excretion and metabolism in cholestatic mice. Additionally, YCZFD downregulated the expression of genes and proteins of the toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway and decreased liver inflammation. The pharmacokinetic study indicated that multiple components showed different pharmacokinetic properties. Among the absorbed components of YCZFD, multiple components activated the transcription of FXR and PXR, regulated BA transporters and metabolic enzyme function, and reduced the gene expression of TLR4 and NF-κB1.

CONCLUSION

YCZFD can ameliorate CCLI by promoting the excretion and metabolism of BAs and inhibiting inflammation via the TLR4/NF-κB signaling pathway. The multiple components of YCZFD could act on BA homeostasis regulation and anti-inflammation, exhibiting a combined effect against CCLI.

Therapeutic effect of yinchenhao decoction on cholelithiasis via mucin in the gallbladder and intestine

Cholelithiasis is a common and frequently occurring disease worldwide that belongs to the category of jaundice in traditional Chinese medicine. Yinchenhao decoction (YD) consists of Artemisia capillaris Thunb., Gardenia jasminoides J.Ellis, and Rheum palmatum L., and is traditionally used to treat jaundice, which has a significant therapeutic effect on cholelithiasis. Our study aimed to investigate the pathological mechanism of cholelithiasis and the therapeutic mechanism of YD via mucin in the gallbladder and intestine. YD was prepared and analyzed using HPLC. The supersaturation stability experiment was designed by the solvent-shift method. The cell transport experiment was conducted by coculture monolayers. The animal experiment was performed using a cholelithiasis model with a high-cholesterol diet. The related indicators were detected by automatic biochemical analyzer, PCR, western blot, or ELISA. Statistics were analyzed using χ2-tests and t-tests. As the results, in cholelithiasis, MUC5AC highly expressed in the gallbladder shortened cholesterol supersaturation and promoted cholesterol crystallization via the inflammatory cytokine signaling pathway; MUC2 highly expressed in the small intestine prolonged cholesterol supersaturation and promoted cholesterol absorption via the inflammatory cytokine signaling pathway. YD inhibited mucin expression in the gallbladder and intestine in a concentration-dependent manner for cholelithiasis treatment by inhibiting the inflammatory cytokine signaling pathway, which was attributed to the active components, including chlorogenic acid, geniposide, and rhein.

Acute Alcoholic Hepatitis

Alcoholic hepatitis is a unique type of alcohol-associated liver disease characterized by acute liver inflammation caused by prolonged heavy alcohol use. Treatment is mostly supportive. The short-term prognosis of acute alcoholic hepatitis depends on liver recovery, and ranges widely from rapid improvement to grim multiorgan failure despite treatment. Refinement of scoring systems have enhanced prognostication to guide clinical decision making in alcoholic hepatitis. Recent advances in the treatment of alcoholic hepatitis have solidified corticosteroids as the cornerstone of treatment to enhance short-term survival, but not intermediate or long-term survival.

The neuroprotective and anti-apoptotic effects of melatonin on hemolytic hyperbilirubinemia-induced oxidative brain damage

Melatonin exerts protection in several inflammatory and neurodegenerative disorders. To investigate the neuroprotective effects of melatonin in an experimental hemolysis-induced hyperbilirubinemia, newborn Sprague-Dawley rats (25-40 g, n = 72) were injected with phenylhydrazine hydrochloride (PHZ; 75 mg/kg) and the injections were repeated at the 24th hour. Rats were treated with saline or melatonin (10 mg/kg) 30 min before the first and second PHZ injections and 24 h after the 2nd PHZ injections. Control rats (n = 24) were injected with saline, but not PHZ. At sixth hours after the last injections of saline or melatonin, all rats were decapitated. Tumor necrosis factor (TNF)-α, IL-1β, IL-10 and brain-derived neurotrophic factor (BDNF) and S100B levels in the plasma were measured. Brain tissue malondialdehyde (MDA), glutathione (GSH) levels and myeloperoxidase (MPO) activities were measured, and brain tissues were evaluated for apoptosis by TUNEL method. In the saline-treated PHZ group, hemoglobin, hematocrit levels were reduced, and total/direct bilirubin levels were elevated when compared to control group. Increased plasma TNF-α, IL-1β levels, along with decreased BDNF, S100B and IL-10 values were observed in the saline-treated PHZ group, while these changes were all reversed in the melatonin-treated group. Increased MDA levels and MPO activities in the brain tissues of saline-treated hyperbilirubinemic rats, concomitant with depleted brain GSH stores, were also reversed in the melatonin-treated hyperbilirubinemic rats. Increased TUNEL(+) cells in the hippocampus of saline-treated PHZ group were reduced by melatonin treatment. Melatonin exerts neuroprotective and anti-apoptotic effects on the oxidative neuronal damage of the newborn rats with hemolysis and hyperbilirubinemia.

Daily administration times of canhuang tablet based on a pharmacodynamic/pharmacokinetic model in jaundiced rats

OBJECTIVE

To study the daily administration times of Canhuang tablet (CHT) for treating jaundice in rats based on a pharmacodynamic/pharmacokinetic model.

METHODS

Rats were modeled by 4% 1-Naphthylisothiocyanate (75 mg/kg, p.o.). After 48 h, CHT was given (p.o.) at 0.75 g/kg once a day, 0.375 g/kg twice a day, and 0.25 g/kg three times a day. Blood was collected from the orbital sinus at different intervals. Levels of liver enzymes and bilirubin were detected using these blood samples. Bile was collected and determined after the first administration of CHT. High-performance liquid chromatography was used to determine the concentration of berberine in bile simultaneously. Time-effect and time-dose curves were then obtained.

RESULTS

Compared with rats taking CHT twice and three times a day, the total amount of bile within 10 h of rats taking CHT once a day were 1.32- and 1.47-fold higher, respectively. There was good consistency between the pharmacokinetics of berberine and the pharmacodynamics of the effect on liver enzymes and bilirubin in vivo. The pharmacokinetic analyses showed that rats administered CHT once daily maintained a higher concentration of berberine in bile for a longer period than rats administered CHT two- and three-times daily.

CONCLUSION

In jaundiced rats, taking CHT once a day is better than taking CHT twice or three times a day. These data may provide a reference for the clinical application of CHT.

Destruction of the hepatocyte junction by intercellular invasion of Leptospira causes jaundice in a hamster model of Weil's disease

Weil's disease, the most severe form of leptospirosis, is characterized by jaundice, haemorrhage and renal failure. The mechanisms of jaundice caused by pathogenic Leptospira remain unclear. We therefore aimed to elucidate the mechanisms by integrating histopathological changes with serum biochemical abnormalities during the development of jaundice in a hamster model of Weil's disease. In this work, we obtained three-dimensional images of infected hamster livers using scanning electron microscope together with freeze-cracking and cross-cutting methods for sample preparation. The images displayed the corkscrew-shaped bacteria, which infiltrated the Disse's space, migrated between hepatocytes, detached the intercellular junctions and disrupted the bile canaliculi. Destruction of bile canaliculi coincided with the elevation of conjugated bilirubin, aspartate transaminase and alkaline phosphatase levels in serum, whereas serum alanine transaminase and γ-glutamyl transpeptidase levels increased slightly, but not significantly. We also found in ex vivo experiments that pathogenic, but not non-pathogenic leptospires, tend to adhere to the perijunctional region of hepatocyte couplets isolated from hamsters and initiate invasion of the intercellular junction within 1 h after co-incubation. Our results suggest that pathogenic leptospires invade the intercellular junctions of host hepatocytes, and this invasion contributes in the disruption of the junction. Subsequently, bile leaks from bile canaliculi and jaundice occurs immediately. Our findings revealed not only a novel pathogenicity of leptospires, but also a novel mechanism of jaundice induced by bacterial infection.

New insights in bilirubin metabolism and their clinical implications

Bilirubin, a major end product of heme breakdown, is an important constituent of bile, responsible for its characteristic colour. Over recent decades, our understanding of bilirubin metabolism has expanded along with the processes of elimination of other endogenous and exogenous anionic substrates, mediated by the action of multiple transport systems at the sinusoidal and canalicular membrane of hepatocytes. Several inherited disorders characterised by impaired bilirubin conjugation (Crigler-Najjar syndrome type I and type II, Gilbert syndrome) or transport (Dubin-Johnson and Rotor syndrome) result in various degrees of hyperbilirubinemia of either the predominantly unconjugated or predominantly conjugated type. Moreover, disrupted regulation of hepatobiliary transport systems can explain jaundice in many acquired liver disorders. In this review, we discuss the recent data on liver bilirubin handling based on the discovery of the molecular basis of Rotor syndrome. The data show that a substantial fraction of bilirubin conjugates is primarily secreted by MRP3 at the sinusoidal membrane into the blood, from where they are subsequently reuptaken by sinusoidal membrane-bound organic anion transporting polypeptides OATP1B1 and OATP1B3. OATP1B proteins are also responsible for liver clearance of bilirubin conjugated in splanchnic organs, such as the intestine and kidney, and for a number of endogenous compounds, xenobiotics and drugs. Absence of one or both OATP1B proteins thus may have serious impact on toxicity of commonly used drugs cleared by this system such as statins, sartans, methotrexate or rifampicin. The liver-blood cycling of conjugated bilirubin is impaired in cholestatic and parenchymal liver diseases and this impairment most likely contributes to jaundice accompanying these disorders.

[Neonatal hyperbilirubinemia and molecular mechanisms of jaundice]

The introductory summarises the classical path of heme degradation and classification of jaundice. Subsequently, a description of neonatal types of jaundice is given, known as Crigler Najjar, Gilberts, DubinJohnson and Rotor syndromes, emphasising the explanation of the molecular mechanisms of these metabolic disorders. Special attention is given to a recently discovered molecular mechanism of the Rotor syndrome. The mechanism is based on the inability of the liver to retrospectively uptake the conjugated bilirubin fraction primarily excreted into the blood, not bile. A reduced ability of the liver to uptake the conjugated bilirubin contributes to the development of hyperbilirubinemia in common disorders of the liver and bile ducts and to the toxicity of xenobiotics and drugs using transport proteins for conjugated bilirubin.

Single liver lobe repopulation with wildtype hepatocytes using regional hepatic irradiation cures jaundice in Gunn rats

BACKGROUND AND AIMS

Preparative hepatic irradiation (HIR), together with mitotic stimulation of hepatocytes, permits extensive hepatic repopulation by transplanted hepatocytes in rats and mice. However, whole liver HIR is associated with radiation-induced liver disease (RILD), which limits its potential therapeutic application. In clinical experience, restricting HIR to a fraction of the liver reduces the susceptibility to RILD. Here we test the hypothesis that repopulation of selected liver lobes by regional HIR should be sufficient to correct some inherited metabolic disorders.

METHODS

Hepatocytes (10(7)) isolated from wildtype F344 rats or Wistar-RHA rats were engrafted into the livers of congeneic dipeptidylpeptidase IV deficient (DPPIV(-)) rats or uridinediphosphoglucuronateglucuronosyltransferase-1A1-deficient jaundiced Gunn rats respectively by intrasplenic injection 24 hr after HIR (50 Gy) targeted to the median lobe, or median plus left liver lobes. An adenovector expressing hepatocyte growth factor (10(11) particles) was injected intravenously 24 hr after transplantation.

RESULTS

Three months after hepatocyte transplantation in DPPIV(-) rats, 30-60% of the recipient hepatocytes were replaced by donor cells in the irradiated lobe, but not in the nonirradiated lobes. In Gunn rats receiving median lobe HIR, serum bilirubin declined from pretreatment levels of 5.17 ± 0.78 mg/dl to 0.96 ± 0.30 mg/dl in 8 weeks and remained at this level throughout the 16 week observation period. A similar effect was observed in the group, receiving median plus left lobe irradiation.

CONCLUSIONS

As little as 20% repopulation of 30% of the liver volume was sufficient to correct hyperbilirubinemia in Gunn rats, highlighting the potential of regiospecific HIR in hepatocyte transplantation-based therapy of inherited metabolic liver diseases.

A polymorphism near IL28B is associated with spontaneous clearance of acute hepatitis C virus and jaundice

BACKGROUND & AIMS

A single nucleotide polymorphism (SNP) upstream of the IL28B gene has been associated with response of patients with chronic hepatitis C to therapy with pegylated interferon and ribavirin and also with spontaneous clearance of acute hepatitis C in a heterogeneous population. We analyzed the association between IL28B and the clinical presentation of acute hepatitis C virus (HCV) infection in a homogeneous population.

METHODS

We analyzed the SNP rs12979860 in 190 women from the German anti-D cohort (infected with HCV genotype 1b via contaminated rhesus prophylaxis) and its association with spontaneous clearance. Clinical data were available in 136 women with acute infection who were also evaluated for IL28B genotype. Based on results of a TaqMan polymerase chain reaction assay, the rs12979860 SNP genotypes studied were C/C, C/T, or T/T.

RESULTS

Spontaneous clearance was more common in patients with the C/C genotype (43/67; 64%) compared with C/T (22/90; 24%) or T/T (2/33; 6%) (P < .001). Jaundice during acute infection was more common among patients with C/C genotype (32.7%) than non-C/C patients (with C/T or T/T) (16.1%; P = .032). In C/C patients, jaundice during acute infection was not associated with an increased chance of spontaneous clearance (56.3%) compared with those without jaundice (60.6%). In contrast, in non-C/C patients, jaundice was associated with a higher likelihood of spontaneous clearance (42.9%) compared with those without jaundice (13.7%).

CONCLUSIONS

The SNP rs12979860 upstream of IL28B is associated with spontaneous clearance of HCV. Women with the C/T or T/T genotype who did not develop jaundice had a lower chance of spontaneous clearance of HCV infection.

Minimally invasive management of biliary complications after laparoscopic cholecystectomy

BACKGROUND

We conducted this prospective study to evaluate the efficacy of percutaneous catheter drainage as a minimally invasive treatment in the management of symptomatic bile leak following biliary injuries associated with laparoscopic cholecystectomy.

METHODS

Twenty two patients with symptomatic bile leak following laparoscopic cholecystectomy underwent percutaneous drainage of the bile collection under ultrasound control. In patients with jaundice and in those with persistent drainage, endoscopic retrograde cholecysto-pancreatography (ERCP) was performed immediately for diagnostic and for therapeutic intervention when appropriate. In other patients, ERCP was performed 4-6 weeks after the discharge from the hospital to document the healing of the leaking site.

RESULTS

Five patients with jaundice were initially treated by a combination of endoscopic plus percutaneous drainage. One of them required surgical treatment following diagnosis of a major duct injury. The other 17 were treated by percutaneous drainage initially and for 14 of them it was definitive treatment. Three patients required sphincterotomy as additional treatment for stopping the leak. There were no complications related to the percutaneous drainage procedure.

CONCLUSIONS

Most patients with bile leakage can be managed successfully by percutaneous drainage. If biliary output does not decrease, endoscopy is needed. In patients with jaundice endoscopic diagnostic and therapeutic procedures should be performed immediately.

Coagulation function in patients with pancreatic carcinoma

BACKGROUND

The coagulation function in patients with pancreatic carcinoma is abnormal and the reason is not very clear. In this study, we retrospectively analyzed the coagulation function in patients with pancreatic carcinoma.

METHODS

From June 2004 to December 2007, 132 patients received diagnosis and treatment in our hospital. The coagulative parameters including the prothrombin time, activated partial thromboplastin time, and fibrinogen levels were collected and studied retrospectively.

RESULTS

The average fibrinogen levels in patients with pancreatic carcinoma, (476.21 +/- 142.05) mg/dl, were significantly higher than in patients with cholangiolithiasis, (403.28 +/- 126.41) mg/dl (P < 0.05). In patients with pancreatic carcinoma, the levels of fibrinogen in the group with jaundice were significantly higher than in patients without jaundice (P < 0.05). In patients who received Pancreaticoduodenectomy, Whipple's operation, the level of fibrinogen in the group with local invasiveness was significantly higher than in the group without invasiveness. The group with lymphatic metastasis had higher levels than the group without lymphatic metastasis (P < 0.05). There was no significant difference of intraoperative blood loss between patients with vitamin K, (748.27 +/- 448.51) ml, and those without vitamin K, (767.31 +/- 547.89) ml (P > 0.05).

CONCLUSIONS

The level of fibrinogen in patients with pancreatic carcinoma was elevated. The elevated fibrinogen level may be associated with invasiveness and lymphatic metastasis. Using vitamin K in perioperation management did not reduce intraoperative blood loss.

Liver injury induced by a Japanese herbal medicine, sairei-to (TJ-114, Bupleurum and Hoelen Combination, Chai-Ling-Tang) R1

The case is reported of a man who showed acute hepatitis with jaundice after he was given a Japanese herbal medicine, sairei-to (TJ-114, Bupleurum and Hoelen Combination, Chai-Ling-Tang). Unusually, the component thought to be responsible for the observed drug-induced liver injury was able to be identified. Lymphocyte migration inhibition testing indicated that the tuber of the perennial herbage Pinellia ternate was the causative agent.

Minocycline blocks acute bilirubin-induced neurological dysfunction in jaundiced Gunn rats

BACKGROUND

Extreme hyperbilirubinemia is treated with double volume exchange transfusion, which may take hours to commence. A neuroprotective agent that could be administered immediately might be clinically useful. Minocycline, an anti-inflammatory and anti-apoptotic semisynthetic tetracycline, prevents hyperbilirubinemia-induced cerebellar hypoplasia in Gunn rats. Acute brainstem auditory evoked potential (BAEP) abnormalities occur after giving sulfadimethoxine to 16-day-old jaundiced Gunn rats to displace bilirubin into tissue including brain.

OBJECTIVE

To assess whether minocycline is neuroprotective in this model of acute bilirubin encephalopathy.

METHODS

We recorded BAEPs at baseline and 6 h after injecting sulfadimethoxine. Minocycline 0.5 mg/kg (n = 4), 5 mg/kg (n = 9), 50 mg/kg (n = 9) or 500 mg/kg (n = 3, all died) was administered 15 min before sulfadimethoxine (0 h). Controls received saline followed by either sulfadimethoxine (n = 13) or saline (n = 7).

RESULTS

At 6 h total plasma bilirubin decreased from 10.84 +/- 0.88 mg/dl (mean +/- SD) to 0.70 +/- 0.35 mg/dl (p <10(-9)) in all sulfadimethoxine-injected groups. At 6 h, there was complete protection against decreased amplitudes of BAEP waves II and III and increased I-II and I-III interwave intervals (brainstem conduction times corresponding to I-III and I-V in humans) with 50 mg/kg minocycline, and partial protection with lower doses.

CONCLUSIONS

Minocycline 50 mg/kg 15 min prior to an intervention that normally produces acute bilirubin neurotoxicity is neuroprotective in jaundiced Gunn rat pups. Further studies are needed to investigate the temporal course and mechanism of neuroprotection. Minocycline, administered immediately, may be clinically useful in treating extreme neonatal hyperbilirubinemia and preventing kernicterus. We believe our model provides an efficient in vivo model to screen and evaluate new agents that are neuroprotective against bilirubin toxicity and kernicterus.

Calculated in vivo free bilirubin levels in the central nervous system of Gunn rat pups

In vitro studies suggest a free bilirubin (B(F)) concentration in the range of 71-770 nmol/L can induce neurotoxicity. In vivo data regarding central nervous system (CNS) B(F) levels have not been determined. We calculated in vivo CNS B(F) levels in Gunn rat pups (15-19 d old; heterozygous nonjaundiced Gunn rats (J/j) and homozygous jaundiced Gunn rats (j/j); saline or sulfadimethoxine treated) based on 1) total brain bilirubin (TBB) content, 2) brain albumin level, 3) CNS bilirubin binding capacity attributable to brain albumin determined using an ultrafiltration technique, and 4) published Gunn rat albumin-bilirubin binding constants (k). Gunn rat brain bilirubin binding capacity was approximately 22 x 10(-3) micromol/g, of which two thirds was accounted for by brain albumin. Using a Gunn rat pup in vivo, k of 9.2 L/micromol, calculated CNS B(F) levels ranged from 72 to 112 nmol/L [95% confidence interval (CI)] in saline and from 59 to 156 nmol/L (95% CI) in sulfadimethoxine-treated J/j pups. These animals demonstrated no neurobehavioral abnormalities and normal cerebellar weight. Calculated CNS B(F) levels were severalfold higher (p < 0.001) in saline (95% CI: 556-1110 nmol/L) and sulfadimethoxine-treated (95% CI: 3461-8985 nmol/L) j/j pups; the former evidenced reduced cerebellar weight; the latter both reduced cerebellar weight and acute neurobehavioral abnormalities. We conclude that calculated CNS B(F) values in j/j pups are substantially higher than those in J/j animals. Given the absence of CNS abnormalities in J/j pups, the presence of such in j/j animals, and the CNS B(F) levels in these groups, we speculate that the CNS B(F) neurotoxicity threshold in vivo is subsumed within the range (71-770 nmol/L) reported in vitro.

Limitation of glucose oxidase method of glucose estimation in jaundiced neonates

The most widely used method for estimation of plasma glucose is that adopted by Trinder's using glucose oxidase-peroxidase (GOD-POD) system. This method gives much lower blood glucose values with blood samples of neonatal jaundice (plasma bilirubin level > 10 mg/dL) of age 10 +/- 5 daysthan with samples of neonates of the same age group without jaundice or older children suffering from other diseases like acute respiratory distress, septicemia.

Transcutaneous bilirubinometry: a noninvasive tool for studying newborn jaundiced rats before and after exposure to light

The homozygous Gunn rat is the most frequently used animal model for the study of neonatal jaundice. We evaluated the applicability of noninvasive transcutaneous bilirubin (TcB) measurements as an index of serum total bilirubin (STB) levels in neonatal rats by comparison to invasive STB measurements. TcB measurements were made during the first 96 h of life with the Model 101 Minolta/Air-Shields Jaundice Meter (JM) and SpectRx BiliCheck System (BC). Measurements with both devices displayed parallel TcB profiles, rapidly rising within 24 h, increasing during the next 6 h, then leveling off after 30 h. Linear regressions for the JM (n = 60) were as follows: STB (mg/dL) = 0.79 (JM) - 0.01 (units, r = 0.95, head); STB (mg/dL) = 0.82 (JM) + 1.51 (units, r = 0.95, upper back); and STB (mg/dL) = 0.74 (JM) + 1.60 (units, r = 0.91, lower back). Mean bias +/- imprecision were as follows: -0.02 +/- 3.99 mg/dL, -0.01 +/- 3.90, and 0.01 +/- 4.28 at the head, upper back, and lower back, respectively. For the BC, only lower back measurements were taken, and the regression was as follows: STB (mg/dL) = 0.77 (BC) + 1.65 mg/dL, (r = 0.93, n = 29) with a mean bias +/- imprecision of -1.08 +/- 3.08 mg/dL. When pups were exposed to light, correlations remained strong but intercepts increased. These results demonstrate that noninvasive TcB measurements correlate highly with STB in the Gunn rat during the first 96 h of life and after exposure to light. We conclude that JM measurements at the head and BC at the lower back reflect STB most reliably and consistently. Thus, in addition to being a useful tool for evaluating jaundice in human neonates, TcB methodology can be used successfully for the noninvasive monitoring of jaundice in neonatal Gunn rats pre- and postlight exposure.

Alleged effect of bile constituents on gentamicin assays

It has been claimed that gentamicin assays on the serum of jaundiced patients give falsely low levels and suggested that the antibiotic in such sera is bound to bile acids and thus is partly inactivated. No evidence of such inactivation has been obtained (i) in the serum of jaundiced patients treated with gentamicin, (ii) in sera with high bilirubin contents to which gentamicin was added, or (iii) when bile or bile acids were added with gentamicin to normal serum.

[Icterus of the newborn caused by indirect bilirubin--recent progress]

Recently a big shift has taken place in the judgment and treatment of jaundice in newborn, caused by increased unconjugated bilirubin level. New techniques evolved for assessing the prognosis of developing jaundice. An important major discovery is the antioxidant effect of bilirubin. We have a broader range of knowledge concerning the mechanism of bilirubin toxicity and for judging the chance of developing kernicterus. The prevention techniques do not stop at prohibiting anti-D immunisation but go on to preventing hydrops foetalis, the life-threatening form of haemolytic disease. There are data about the complications of phototherapy and EPO treatment for prolonged anaemia.

Hepatocyte apoptosis and the expression of Bcl-2 and Bax in Yin-jaundice rats

OBJECTIVE

To investigate the effects of Yinchen Shufu Decoction on hepatocyte apoptosis and the expression of its apoptosis-regulating gene Bcl-2 and Bax in Yin-jaundice rats.

METHODS

Forty-eight rats were divided randomly into 4 groups: the normal control group, Yin-jaundice model group, Yang-jaundice model group, Yinchen Shufu Decoction treatment group. The TUNEL assay and the immunohistochemistry assay were used to detect the apoptosis of hepatocytes and the expression of Bcl-2 and Bax in hepatocytes respectively.

RESULTS

The rate of apoptosis cells in Yin-jaundice model group was higher significantly than that in Yang-jaundice model group and normal control group (P<0.01), the expression of Bcl-2 in Yinchen Shufu Decoction treatment group was higher significantly than that in Yin-jaundice model group (P<0.01 or P<0.05), and the expression of Bax in it was lower significantly than that in Ying-jaundice model group (P<0.01 or P<0.05).

CONCLUSION

Yinchen Shufu Decoction can prevent hepatocyte apoptosis perhaps by up-regulating the expression of Bcl-2 and down-regulating the expression of Bax. It is one of the mechanisms of its treatment on Yin-jaundice.

Immunohistochemical localization of calcium-binding proteins in the brainstem vestibular nuclei of the jaundiced Gunn rat

Vestibular gaze and postural abnormalities are major sequelae of neonatal hyperbilirubinemia. The sites and cellular effects of bilirubin toxicity in the brainstem vestibular pathway are not easily detected. Since altered intracellular calcium homeostasis may play a role in neuronal cell death, we hypothesized that altered expression of calcium-binding proteins may occur in brainstem vestibular nuclei of the classic animal model of bilirubin neurotoxicity. The expression of the calcium-binding proteins calbindin-D28k and parvalbumin in the brainstem vestibular pathways and cerebellum of homozygous recessive jaundiced (jj) Gunn rats was examined by light microscopy and immunohistochemistry at 18 days postnatally and compared to the findings obtained from age-matched non-jaundiced heterozygous (Nj) littermate controls. Jaundiced animals exhibited decreased parvalbumin immunoreactivity specifically in synaptic inputs to superior, medial, and inferior vestibular nuclei, and to oculomotor and trochlear nuclei, whereas the neurons retained their normal immunoreactivity. Jaundiced animals also demonstrated a decrease in calbindin expression in the lateral vestibular nuclei and a paucity of calbindin-immunoreactive synaptic endings on the somata of Deiters' neurons. The involved regions are related to the control of the vestibulo-ocular and vestibulospinal reflexes. Decreased expression of calcium-binding proteins in brainstem vestibular neurons may relate to the vestibulo-ocular and vestibulospinal dysfunction seen with clinical kernicterus, and may provide a sensitive new way to assess bilirubin toxicity in the vestibular system.

Excessive hepatic copper accumulation in jaundiced rats fed a high-copper diet

The response of copper metabolism to dietary copper challenge was investigated in jaundiced rats with elevated plasma concentrations of conjugated bilirubin as a result of impaired canicular transport of bilirubin glucuronides. Control and jaundiced rats were fed purified diets with either normal (64 micromol Cu/kg) or high (640 micromol Cu/kg) concentration of added copper. Copper loading produced a greater increase in hepatic copper concentrations in the jaundiced than in control rats. The greater dietary-copper-induced increase in hepatic copper in the jaundiced rats can be explained by the observed smaller rise in biliary copper excretion and a greater efficiency of dietary copper absorption. In individual rats, there was a positive relationship between hepatic copper concentrations and biliary copper concentrations. It is suggested that not the transport of copper from liver cells to bile but that from plasma to bile is diminished in the jaundiced rats. The elevated plasma copper concentrations in the jaundiced rats may support this suggestion.

Acute hepatitis induced by alpha-interferon in a patient with chronic hepatitis C

Hepatic adverse effects occur very rarely with alpha-interferon therapy. A case of acute hepatitis induced by alpha-interferon in a 33-year-old man with chronic hepatitis C is described. The patient developed acute hepatitis with very high aminotransferase activity and jaundice. After discontinuing alpha-interferon therapy, hepatitis resolved rapidly. The immune-mediated mechanism is the most probable cause of this hepatitis.

Role of cytochrome P450 1A2 in bilirubin degradation Studies in Cyp1a2 (-/-) mutant mice

In congenital jaundice, which is due to defects of bilirubin gluruconidation, bilirubin is degraded by an alternative pathway into unidentified products. Previously, it was shown that plasma bilirubin levels can be decreased in rats with this defect by inducers of CYP1A enzymes. Here, liver microsomes from rats or mice treated with beta-naphthoflavone (BNF) or 3-methylcholanthrene (3 MC) had increased activity for bilirubin degradation. The activity was further stimulated by addition of the coplanar molecule 3,4,3',4'-tetrachlorobiphenyl (TCB). There was more stimulation of bilirubin degradation by TCB in microsomes from BNF-treated rats than in microsomes from BNF-treated mice. CYP1A1 to CYP1A2 ratios were greater in rats treated with BNF. In Cyp1a2 (-/-) mutant mice, 3-MC treatment did not increase the rate of bilirubin degradation, but TCB increased this degradation severalfold. Between SWR and C57BL/6 inbred mouse strains that have a 2-fold difference in hepatic constitutive CYP1A2 levels, there was also a 2-fold difference in bilirubin degradation; TCB did not stimulate in either strain. We conclude that CYP1A2 is responsible for microsomal bilirubin degradation in the absence of TCB. TCB was required for bilirubin degradation by CYP1A1. Manipulation of CYP1A2 may be of therapeutic benefit in patients with these diseases of bilirubin conjugation.

An oral endothelin-A receptor antagonist blocks collagen synthesis and deposition in advanced rat liver fibrosis

BACKGROUND & AIMS

Endothelin 1 induces contraction, proliferation, and collagen synthesis of hepatic stellate cells in vitro, which may be mediated via the endothelin A receptor. It is unknown if specific blockade of the endothelin A receptor inhibits hepatic fibrosis in vivo.

METHODS

Groups of 10-20 rats with bile duct occlusion were treated with the nonpeptide endothelin-A receptor antagonist LU 135252 at 80 mg. kg(-1). day(-1) from week 1-6 or from week 4-6, or with LU at 10 mg. kg(-1). day(-1) from week 1-6. Animals with bile duct occlusion alone and sham-operated rats without or with LU at 80 mg. kg(-1). day(-1) over 6 weeks served as controls. After 6 weeks, parameters of fibrogenesis were determined.

RESULTS

LU treatment led to improved histology, paralleled by a dose-dependence up to 60% reduction of liver collagen, even when administered at an advanced fibrosis stage. This was accompanied by a decreased messenger RNA of hepatic procollagen alpha1(I) and tissue inhibitor of metalloproteinase 1, 2 major effectors of fibrosis, and of serum procollagen type III, a surrogate marker of liver fibrogenesis.

CONCLUSIONS

Selective endothelin-A receptor blockade can dramatically reduce collagen accumulation in rat secondary biliary fibrosis, a model refractory to most potential antifibrotic agents. Endothelin-A receptor antagonists are promising antifibrotic agents in chronic liver disease.

Expression of the alpha and beta subunits of Ca2+/calmodulin kinase II in the cerebellum of jaundiced Gunn rats during development: a quantitative light microscopic analysis

The homozygous (jj) jaundiced Gunn rat model for hyperbilirubinemia displays pronounced cerebellar hypoplasia. To examine the cellular mechanisms involved in bilirubin toxicity, this study focused on the effect of hyperbilirubinemia on calcium/calmodulin-dependent kinase II (CaM kinase II). CaM kinase II is a neuronally enriched enzyme which performs several important functions. Immunohistochemical analysis of alternating serial sections were performed using monoclonal antibodies for the alpha and beta subunits of CaM kinase II. Measurements were made of the total numbers of stained cells in each of the deep cerebellar nuclei and of Purkinje and granule cell densities in cerebellar lobules II, VI, and IX. The beta subunit was present in Purkinje cells and deep cerebellar nuclei of both groups at all ages, but only granule cells which had migrated through the Purkinje cell layer showed staining for beta subunit; external granule cells were completely negative. Many Purkinje cells had degenerated in the older animals, and the percent of granule cells stained for beta subunit was significantly reduced. The alpha subunit was found exclusively in Purkinje cells, although its appearance was delayed in the jaundiced animals. Sulfadimethoxine was administered to some jj rats 24 h or 15 days prior to sacrifice to increase brain bilirubin concentration. Results showed that bilirubin exposure modulated both alpha and beta CaM kinase II subunit expression in selective neuronal populations, but sulfadimethoxine had no acute effect on enzyme immunoreactivity. Thus, developmental expression of the alpha and beta subunits of CaM kinase II was affected by chronic bilirubin exposure during early postnatal development of jaundiced Gunn rats.

Interference of cerebral near-infrared oximetry in patients with icterus

Near-infrared spectrophotometry assesses cerebral oxygen saturation (ScO(2)) based on the absorption spectra of oxygenated and deoxygenated hemoglobin and the translucency of biological tissue in the near-infrared band. In patients with icterus, however, bilirubin can potentially hinder cerebral oximetry. In 48 patients undergoing orthotopic liver transplantation, we related total plasma bilirubin to ScO(2) as determined from spectrophotometry with wavelengths of 733 and 809 nm. Before surgery, ScO(2) was 59% (15%-78%) (median with range) and bilirubin was 71 (6-619) micromol/L with a negative correlation (r = -0.72; P < 0.05). The 95% prediction interval included the lowest measurable ScO(2) of 15% at a bilirubin level of 370 micromol/L. During reperfusion of the grafted liver, the ScO(2) increased by 7% (-8% to 17%) (P < 0.05), and bilirubin did not influence this increase. In one patient, the ScO(2) remained below 15% despite a decrease in bilirubin from 619 to 125 micromol/L, suggesting that tissue pigmentation deposits also absorb light. In conclusion, bilirubin dampens the spectrophotometry-determined cerebral oxygen saturation at 733 and 809 nm. A bilirubin level of 370 micromol/L, tissue pigment deposits, or both, may render determination of cerebral oxygen saturation impossible. Even at high bilirubin values, changes in cerebral perfusion may be visible.

IMPLICATIONS

In 48 patients undergoing liver transplantation, the interference of icterus on cerebral oximetry by near-infrared light was investigated. Bilirubin absorbed the near-infrared light and lowered the measured cerebral oxygen saturation. Even at high bilirubin values, changes in cerebral oxygenation, as seen during reperfusion of the grafted liver, may be visible.

Differentiation and diagnosis of jaundice

Bilirubin metabolism is a complex and fascinating example of the body's ability to discard, renew, and recycle vital elements. Jaundice is the warning sign for derangements in this system. As is true of pain, jaundice is a powerful impetus for visiting a healthcare provider. Usually associated with hepatitis by a nonclinician, the origins of jaundice can range from benign to fatally malignant. Patients may have any number of idiopathic or nosocomial conditions that can contribute to an icteric state. This review delineates the steps of bilirubin metabolism, enumerates the sources of bilirubin derangement, and examines elements of patient condition and therapeutics that can contribute to hyperbilirubinemia and jaundice.

Myocardial high-energy phosphates and hepatic redox state in jaundiced rats

BACKGROUND

The mechanism underlying the fatal complications in jaundiced states after shock has not been fully clarified. The present study was designed to examine the effect of hemorrhagic shock on myocardial high-energy phosphate stores and the arterial ketone body ratio (AKBR:acetoacetate/beta-hydroxybutyrate), which reflects the redox state of the liver mitochondria, in normal and jaundiced rats.

MATERIALS AND METHODS

At 1 week after ligation of the common bile duct, hemorrhagic shock was induced by exsanguination (mean arterial blood pressure = 40 mmHg) and maintained for 2 h. Serial changes in AKBR were measured. The myocardial adenine nucleotides phosphocreatine (PCr) and inorganic phosphate (Pi) were determined before and after hemorrhagic shock.

RESULTS

Before shock, myocardial ATP in the jaundiced group was lower than that in the sham group. However, the myocardial PCr levels in the two groups did not differ. After reinfusion of the shed blood, ATP and PCr recovered to the preshock levels in the sham group. However, ATP and PCr were further increased in the jaundiced group. At 60 min after reinfusion, AKBR recovered to the normal level in the sham group, but decreased below 0.7 in the jaundiced group. Metabolic acidosis was more severe in the jaundiced group than in the sham group.

CONCLUSIONS

The decrease in AKBR indicated irreversible metabolic acidosis. As a result, fatal circulatory failure occurred, although the phosphoenergetic level in the myocardium was sufficiently maintained.

Production of ascorbate and hydroxyl radicals in the liver of LEC rats in relation to hepatitis

The production of radicals was examined in vitro in liver supernatant prepared from LEC rats of different ages before and after the onset of jaundice. Each liver supernatant was subjected to heat-treatment at 90 degrees C for 10 min to remove heat-labile proteins, and then the production of radicals in the resultant supernatant in the presence of hydrogen peroxide and 5,5'-dimethyl-1-pyrroline oxide (DMPO) was studied by ESR. Two sharp ESR signals that completely decayed with time within 5 min after the addition of hydrogen peroxide were observed for the sample prepared from LEC rats before the onset of jaundice, followed by the appearance of four signals of a hydroxyl radical-DMPO adduct after 5 min. On the other hand, in the supernatant prepared from LEC rats after the onset of jaundice, the former two signals were not observed or observed only marginally, and the signals of the hydroxyl radical-DMPO adduct showed a different pattern of decay from that for the supernatant prepared from LEC rats before the onset of jaundice. With the addition of ascorbic acid to the liver supernatant prepared from LEC rats after the onset of jaundice, the former signals of the ascorbate and hydroxyl radicals reappeared. The present results suggest that ascorbate and hydroxyl radicals are produced in the liver of LEC rats with the onset of jaundice, depending on the relative ratio of ascorbic acid and cuprous ions.

[The importance of myoglobin in the pathogenesis of leptospirosis]

Measurements were made of serum and urine myoglobin in 48 patients with leptospiral jaundice (LJ) and 56 patients with various acute infections. At the height of LJ blood myoglobin level reached 28.96 +/- 4.3 micrograms/l (normal concentration 0.315 +/- 0.002 microgram/l). Compared to acute pneumonia, acute viral hepatitis, tonsillitis, erysipelas, diphtheria, health values, the ratio of serum myoglobin to urine myoglobin in leptospirosis made up 45.25 against 5.4, 4.8, 6.8, 3.7, 1.8 and 1.3, respectively. A relationship was found between concentrations of myoglobin, bilirubin, creatinine in the blood and leptospirosis severity. Elevation of serum myoglobin as a manifestation of specific myositis is pathognomic for leptospirosis and contributes to the onset of acute renal failure and disturbance of bilirubin metabolism. Quantitation of blood myoglobin may be helpful as an additional test for leptospirosis severity.

Restricted redox oscillation in oxidative phosphorylation in jaundiced rat liver mitochondria and its relation to calcium ion

High morbidity and mortality in surgical management for patients with obstructive jaundice was greatly attributed to the metabolic derangements in jaundiced liver mitochondria. Isolated liver mitochondria from jaundiced rat, produced by common bile duct ligation, were used to study the relationship among NADH level, oxygen consumption, and extramitochondrial calcium concentration. Alterations in NADH percentage and oxygen consumption were accomplished by incubating mitochondria with different substrates and monitoring oxygen consumption and NAD(P)H fluorescence simultaneously. In jaundiced liver mitochondria with glutamate + malate as substrate, respiration increased after the addition of exogenous Ca2+ at concentrations of 1 x 10(-7), 5 x 10(-7), and 1 x 10(-6) M. The maximal effect occurred at 5 x 10(-7) M. With different NADH-related substrates, the NAD(P)H fluorescence measurements (X axis) correlated linearly with state 3 respiration (Y axis), the slopes of the correlation curves being 2.27 and 0.79 in control and jaundiced mitochondria, respectively. After the addition of 5 x 10(-7) M Ca2+, the respirations of both control and jaundiced mitochondria increased and the slope for jaundiced mitochondria rose to 1.67. The matrix free Ca2+ concentration in jaundiced mitochondria, measured by fluo-3 loading, was higher than that in controls (162.1 +/- 16.7 nM, vs 129.7 +/- 12.6 nM, P < 0.01), while the matrix free/total Ca2+ ratio decreased from 34.9 +/- 6.0 (x10(-6)) to 27.2 +/- 4.4 (x10(-6), 9- < 0.05. The amplitude of the change in NAD(P)H fluorescence was reduced in jaundiced rat liver mitochondria and this correlated with the depression of respiration. A decrease in free/total Ca2+ ratio may be closely related to mitochondrial respiratory impairment in jaundice.

Age-dependent and region-specific differences in the distribution of trace elements in 7 brain regions of Long-Evans Cinnamon (LEC) rats with hereditary abnormal copper metabolism

Cu, Mn, Mo, Rb and Zn concentrations of 7 brain regions in LEC rats were determined before (4 and 10 weeks old) and after (20 weeks old) the onset of jaundice. Cu in the LEC rat brain was less concentrated in all regions at 4 weeks of age and in synaptosomal fractions at 10 weeks but, conversely, more concentrated in 3 regions at 20 weeks than in control rats. Furthermore, Mo and Rb in 6 regions at 10 weeks of age and Mn at 20 weeks were more concentrated in the LEC rat brain than in control rats. These results showed that abnormal distributions of trace elements exist in the LEC rat brain before the onset of jaundice.

A unique bilirubin-UDP-glucuronosyltransferase deficiency related to neonatal jaundice in mice

This report describes biochemical and cellular characterization of a spontaneous mutation in ICR mice; the mutation has been phenotypically characterized as autosomal recessive jaundice in neonates and juveniles and given the gene symbol hub (J. Hered. 76:441-446, 1985; Mouse Newslett. 73:28, 1985). The results obtained demonstrate that (1) mice homozygous for the mutation are deficient in bilirubin-UDP-glucuronosyltransferase activity, and there is no deficiency in heterozygous mice, (2) the deficiency is lifelong, even though the clinical symptom of jaundice is transitory and restricted to neonates or juveniles, (3) bilirubin-UDP-glucuronosyltransferase activity in mutant and nonmutant mice is similarly induced by triiodothyronine, (4) glucuronidation and xylodation of bilirubin probably occur as the result of separate enzyme forms in mice, and (5) Western analysis using antibody to rat bilirubin-UDP-glucuronosyltransferase indicates that although there is no electrophoretic mobility difference, there is a diffuse band missing in mutant mice. Hepatic hyperplasia, cytomegaly, single-cell necrosis, and eosinophilic foci are also pleiotropic traits associated with homozygous but not heterozygous hub. The hub/hub mouse will be useful in the study of substrate specificity and regulation within a complex gene family and, perhaps, provide a new and useful animal model for the long-term health effects of deficiency in the metabolism of xenobiotics cleared via UDP-glucuronosyltransferase.

Investigation of the role of reactive oxygen species in bilirubin metabolism in the Gunn rat

It has been previously established that the attenuation of hepatic lipid peroxidation by a fat-free diet is accompanied by a marked rise in plasma bilirubin in Gunn rats. Present in vitro studies confirmed that microsomal lipid peroxidation caused the concurrent degradation of added bilirubin but failed to show that microsomal superoxide, hydroxyl radical or hydrogen peroxide would degrade bilirubin. Moreover, although injection of vitamin E completely inhibited microsomal lipid peroxidation and bilirubin degradation it had no effect on plasma bilirubin. No evidence has therefore been obtained that in Gunn rats, in the absence of bilirubin glucuronidation, that reactive oxygen species provide a significant physiological pathway of bilirubin disposal.

Glomerular filtration rate and creatinine production in adult icteric patients

Various methods for serum creatinine determination were compared and validity of the Cockroft-Gault algorithm for calculating creatinine clearance was tested in adult icteric patients. Using conventional Jaffé assays, negative interference is proportional to the serum bilirubin content. Pretreatment of the serum with bilirubin oxidase was more efficient in eliminating bilirubin than pretreatment with potassium ferricyanide. Due to a continued creatine-poor diet and liver dysfunction, erythrocyte creatine levels and creatinine output rate were decreased. Median effect (creatinine equivalent) of non-specific chromogens in the unmodified Jaffé assay was 21 mumol/l (range: 1-108 mumol/l), vs. 19 mumol/l (range: 16-26 mumol/l) for the reference population. In the absence of multi-organ failure, the Cockroft-Gault algorithm could be used for estimating glomerular filtration rate. In patients with multiple organ failure however, we recommend correction for both bilirubin and non-specific chromogens for measuring the serum creatinine concentration.

Changes in hepatic copper distribution leading to hepatitis in LEC rats

Copper (Cu) accumulating in the liver of LEC (Long-Evans with a cinnamon-like coat color) rats due to a hereditary metabolic disorder is assumed to cause acute hepatitis with severe jaundice or chronic hepatitis leading to cancer. Changes in concentrations and distributions of Cu, zinc and iron in the liver of LEC rats were determined to find the relationship between the chemical forms and the toxicity. Female rats after delivery were used because of high susceptibility to acute hepatitis. They were divided into four stages according to the development of jaundice. Cu concentrations in the whole liver and the supernatant decreased with development of jaundice. Distribution profiles of Cu, zinc, iron and sulfur on a gel filtration column by HPLC-ICP showed that Cu in the liver supernatant was mostly bound to metallothionein (MT) before jaundice (stage 1), high molecular weight proteins and MT at the beginning of jaundice (stages 2 and 3), and then mostly to MT at severe jaundice (stage 4) though the concentration of Cu at this stage was decreased to about 50% of stage 1. The results suggest that Cu accumulating as MT in the liver is liberated drastically after exceeding the capacity of MT synthesis, and the liberated Cu causes acute hepatitis.

Vitamin A status in biliary atresia: intestinal absorption and liver storage of retinol

The vitamin A status of 19 patients with corrected biliary atresia was examined. They had been receiving 5,000 IU of oral vitamin A daily postoperatively. Plasma vitamin A levels in the nonjaundiced group were almost within normal range, whereas those in the jaundiced group were significantly low compared with the controls. In the oral vitamin A tolerance test, plasma vitamin A levels increased from 33.1 +/- 11.8 to 215.4 +/- 100.7 micrograms/dL in the nonjaundiced group, and from 23.1 +/- 10.3 to 209.8 +/- 154.2 micrograms/dL in the slightly jaundiced group, at 4 hours after the administration of vitamin A, showing no difference between both group and control. In the severely jaundiced group, plasma vitamin A levels increased from 13.5 +/- 3.5 to 30.0 +/- 14.6 micrograms/dL, a significantly smaller increase compared with controls. However, liver vitamin A levels were greater than 20 micrograms/g liver in all patients, irrespective of the presence of jaundice. This study suggested that nutritional support to facilitate the synthesis of retinol-binding protein may be an important factor in addition to vitamin A supplementation.

Accumulation of organic anion in intracellular vesicles of cultured rat hepatocytes is mediated by the canalicular multispecific organic anion transporter

Transport of organic anions within hepatocytes and the possible involvement of intracellular vesicles were studied with fluorescence microscopy. For this purpose monochlorobimane, a nonfluorescent hydrophobic compound that readily permeates into cells and is conjugated with glutathione to form the fluorescent glutathione bimane, was used. In the isolated perfused livers of normal rats, glutathione bimane is rapidly secreted into bile. In contrast, in our study of livers from mutant TR- rats, a 100-fold reduction in glutathione bimane secretion into bile occurred. Mutant TR- rats have an inherited defect in the canalicular multispecific organic anion transporter, which mediates the ATP-dependent secretion of a wide range of organic anions over the canalicular membrane into bile. When cultured Wistar and TR- hepatocytes were loaded with glutathione bimane, both cell types displayed a strong cytosolic fluorescence. Wistar cells completely lost this cytosolic fluorescence at incubation on monochlorobimane-free medium because of secretion of glutathione bimane. A clear punctate fluorescence remained, however, which was scattered through the cell with some perinuclear concentration. In some cells vesicular fluorescence was also concentrated around a canaliculus. In contrast, TR- cells lost their cytosolic fluorescence more slowly and completely lacked the vesicular fluorescence. Making cells selectively permeable with digitonin directly after loading them with glutathione bimane to remove cytosolic fluorescence again revealed the presence of fluorescent vesicles in Wistar cells and their absence in TR- cells. In Wistar cells vesicular fluorescence could be increased by preincubation with monensin or methylamine, compounds that have been shown to interfere with plasma membrane recycling. In conclusion, these results suggest that apart from secretion over the plasma membrane, the canalicular multispecific organic anion transporter may be involved in accumulation of organic anion in intracellular vesicles. It is hypothesized that this intracellular localization of the canalicular multispecific organic anion transporter is caused by recycling of the transporter between the plasma membrane and intracellular membranes.