HFE mutations and hemochromatosis in Danish patients admitted for HFE genotyping.

Analysis of the common C282Y and H63D mutations in the HFE gene is widely used to diagnose hereditary hemochromatosis (HH). The aim of this study was to evaluate the efficiency with which different hospitals and general practitioners select patients for HH genotype and to determine the distribution of HFE mutations in such patients. Nine hundred unrelated patients from Danish hospitals and general practitioners (group A) and 69 consecutive patients from a specialized liver unit (group B) were examined for HFE substitutions using multiplex real-time polymerase chain reaction. In group A we found 13.0% (0%) C282Y homozygotes, 5.8% (2.6%) H63D/C282Y compound heterozygotes and 1.9% (3.1%) S65C heterozygotes. The values for 420 Danish blood donors are shown in parentheses. The distribution of genotypes in group B was similar to that of the blood donors. Serum ferritin, transferrin iron saturation and pathological data were collected from 38 randomly selected C282Y homozygotes, 36 H63D/C282Y compound heterozygotes, 19 H63D heterozygotes, 17 S65C heterozygotes and 144 wild-types. All of the C282Y homozygotes and 28% of the compound heterozygotes were diagnosed as HH patients. There was no evidence of HH in the H63D homozygotes or S65C heterozygotes. Moreover, 7 wild-type patients, 2 C282Y heterozygote patients and one H63D heterozygote patient fulfilled the criteria for HH. The significant enrichment of HH among associated genotype samples submitted for HFE testing indicates that the clinical selection is generally adequate. However, the study showed substantial deviation in the selection efficiency among the various hospitals and general practitioners.

Growth hormone and insulin-like growth factor-I counteracts established steroid catabolism in rats by effects on hepatic amino-N degradation.

BACKGROUND/AIMS: Long-term steroid treatment causes protein wasting. Liver contributes towards this by upregulating ureagenesis. Growth hormone (GH) and insulin-like growth factor-I (IGF-I) are anabolic agents with specific hepatic effects. It is unknown whether IGF-I alone and/or in combination with GH have any effect on established hepatic amino-N catabolism during long-term glucocorticoid treatment. METHODS: We measured the spontaneous (UNSR) and the substrate standardized rate of urea nitrogen synthesis (STUNSR), N-balance and mRNA levels of urea cycle enzymes in controls (placebo) and four longterm steroid treated groups given (1) prednisolone 4 mg/kg/day during 28 days (St) (2) +GH 1 mg/kg/day from day 21-28 (StGH) (3) +IGF-I 1.5 mg/kg/day 21-28 (StIGF) (4) GH +IGF-I (StGHIGF). RESULTS: Steroid induced weight loss was stepwisely reversed by IGF-I, GH and both. UNSR, STUNSR and mRNA levels of urea cycle enzymes in the liver increased markedly after steroid treatment, and was normalized after co-administration of GH and IGF-I. N-balance improved after GH and IGF-I administration. CONCLUSIONS: Our results expands the knowledge of beneficial effects of GH on short-term steroid catabolism to include effects of IGF-I and IGF-I combined with GH on long-term steroid catabolism. Both peptides prevent steroid induced hepatic protein wasting and thereby contribute towards whole body anabolism. The effect in vivo is probably due to an effect of the peptides on urea cycle enzyme mRNA.

Cholestasis and regulation of genes related to drug metabolism and biliary transport in rat liver following treatment with cyclosporine A and sirolimus (Rapamycin).

Cyclosporine A and sirolimus are used alone or in combination as immunosuppressants in organ transplantation. To elucidate hepatic side effects, we examined hepatic mRNA of proteins involved in biliary and hepatocellular transport of drugs, formation of glutathione (GSH) and drug metabolising cytochrome P-450 enzymes (CYPs) in rats treated orally for 2 weeks with cyclosporine A (15 mg/kg/day), sirolimus (0.4 mg/kg/day), their combination (same doses), or vehicle. Liver function tests (alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase and bilirubin) in blood were then analysed as were hepatic mRNA levels of canalicular transport proteins (Mrp2, Bsep, Mdr1b and Mdr2), sinusoidal transport proteins (Ntcp, Oatp1 and Oatp2), GSH related enzymes (gamma-glutamylcysteine synthetase light (GCSlc) and heavy (GCShc) chain subunits and glutathione-S-transferase) and CYPs (CYP3A9, CYP1A2, CYP2E1 and CYP2BI/II). Cyclosporine A caused moderate cholestatic changes in liver enzymes, which was synergistically exacerbated by sirolimus. The data suggest that the underlying mechanisms behind cholestasis were not totally identical in the different treatment regimens. Cholestasis secondary to cyclosporine A could be related to reduction in mRNA expression of GSH synthesising enzymes and Mrp2, leading to reduced protection against oxidative stress and reduced bile acid-independent bile flow. After sirolimus treatment, Mrp2 mRNA was also reduced together with reduced levels of most CYPs and increased Oatp2, possibly leading to accumulation of toxic metabolites in the hepatocytes. The enhanced cholestatic effect of the combination treatment could be related to reduced GSH synthesising enzymes and even more pronounced reduction in Mrp2 mRNA and increase of Oatp2 mRNA.

Temporal profile of total, bound, and free Gc-globulin after acetaminophen overdose.

Low admission values of the actin scavenger Gc-globulin are associated with an adverse outcome in acetaminophen (paracetamol) overdose. This prospective longitudinal study including 84 patients with acetaminophen overdose characterizes the temporal profile of Gc-globulin during the entire length of hospitalization. Serum Gc-globulin (total, actin bound, and free) levels and actin-complex ratio were measured on admission and every 12 hours until discharge. In 32 patients without hepatotoxicity (non-HEPTOX group; peak transaminase levels < 1,000 U/L), total and free Gc-globulin levels and complex ratio remained within normal range during hospitalization. Among 52 patients with hepatotoxicity (HEPTOX group; peak transaminase levels > 1,000 U/L), 15 patients had hepatic encephalopathy (HE), and 37 patients did not. In these 2 groups, total and free Gc-globulin levels decreased to 97 and 50 mg/L and 148 and 86 mg/L, respectively (normal mean, 340 and 299 mg/L), the nadir occurring at 72 hours postoverdose. Complex ratio peaked at 60 hours at levels more than 3-fold greater than normal. Conversely, bound Gc-globulin remained within normal levels for all patients throughout the observation period. At day 2, a total Gc-globulin cutoff value of less than 120 mg/L correctly predicted HE in 75%, and a value greater than 120 mg/L correctly predicted the absence of HE in 91% of patients. In conclusion, Gc-globulin is severely stressed in patients with hepatotoxicity. Extreme values occurred at 60 to 72 hours postoverdose, a period in which Gc-globulin protection against actin toxicity may be inadequate. A total Gc-globulin level less than 120 mg/L on day 2 is a good predictor of later HE. Bound Gc-globulin is maintained at constant levels independent of total Gc-globulin levels, suggesting a balanced upregulation of the removal of bound Gc-globulin even under conditions with increased actin release.

Effects of a Brussels sprouts extract on oxidative DNA damage and metabolising enzymes in rat liver.

The apparent anticarcinogenic effect of cruciferous vegetables found in numerous epidemiological and experimental studies has been associated with their influence on phase I and phase II metabolising enzymes as well as on the antioxidant status. In the present study we investigated the effect of administration of a Brussels sprouts extract on the expression at the mRNA level and/or catalytic activity in rat liver of three phase I enzymes [cytochrome P450-1A2 (CYP1A2),-2B1/2 (CYP2B1/2) and-2E1 (CYP2E1)] and two phase II enzyme [NADPH:quinone reductase (QR) and glutathione S-transferase pi 7 (GSTpi)], all previously suggested to be induced by vegetables. We also examined the activity and/or expression of several important antioxidant enzymes: glutathione peroxidase (GPx), catalase and gamma-glutamyl-cysteine synthetase (GCS) and the activity of the repair enzyme 8-oxoguanine DNA glycosylase (OGG1). QR, GPx and catalase activity was also assessed in the kidneys. In order to examine a possible effect of the Brussels sprouts related to oxidative stress, we measured oxidative DNA damage in terms of 7-hydro-8-oxo-2'-deoxyguanosine (8-oxodG) and lipid peroxidation in terms of malondialdehyde (MDA) formation in the liver. Oral administration of an aqueous Brussels sprouts extract for 4 days was found to induce the expression of GST 1.3-fold (P < 0.05) and the activity of QR 2.6-fold in rat liver (P < 0.05). No significant differences were seen in the expression of the phase I enzymes. No differences in antioxidant enzyme activity/expression or OGG1 activity were observed. In a second experiment, administration of the Brussels sprouts extract for 3 or 7 days was found to increase the level of 8-oxodG in rat liver from 0.75 to 0.97 per 10(5) dG and from 0.81 to 0.97 per 10(5) dG, respectively (P < 0.05). No effects on MDA levels were found. The present results support the data obtained in several studies that consumption of cruciferous vegetables is capable of inducing various phase II enzyme systems. However, the observed increase in oxidative DNA damage raises the question of whether greatly increased ingestion of cruciferous vegetables is beneficial.

Autoprotection in acetaminophen intoxication in rats: the role of liver regeneration.

Autoprotection by acetaminophen, i.e. increased resistance to toxic effects caused by pretreatment, is a well-known phenomenon. The purpose of the present work was to identify mechanisms for increased acetaminophen tolerance induced by pretreatment of rats. One group of female Wistar rats (pretreated rats) received acetaminophen orally in increasing doses (1 to 4.3 g/kg) twice a week for 3 weeks, one group (naïve rats) received the vehicle. At time zero pretreated rats received a toxic dose of 7.5 g/kg (100% lethal in naïve rats), and naïve rats received a toxic dose of 4.3 g/kg. Blood and liver tissue were collected before and 12, 24, 36, and 48 hr after the toxic dose and were analysed for hepatic glutathione and cysteine contents, hepatic glutathione-S-transferase and blood alanine aminotransferase activity, as well as acetaminophen concentration in plasma. Steady-state mRNA levels of proteins involved in acetaminophen detoxification, cell division and acute phase response were measured, liver tissue was examined for proliferating cell nuclear antigen and degree of hepatocyte necrosis. Six naïve rats not receiving acetaminophen served as controls. The mortality was the same in pre-treated and naïve rats (33 percent). Thus, pretreatment increased the tolerance twice. Before the toxic dose pretreated rats compared to control rats had higher activity of glutathione-S-transferase (liver) and alanine aminotransferase (serum), higher hepatic mRNA level of glutathione-S-transferase and gamma-glutamylcysteine synthetase heavy and light chain subunits, and lower hepatic concentration of glutathione, cysteine and mRNA of CYP1A2 than control rats. After the toxic dose, the mRNA levels of glutathione-S-transferase, gamma-glutamylcysteine synthetase heavy and light chain subunits, and CYP1A2 in naïve rats rose, approaching those of pretreated rats. Proliferating cell nuclear antigen labelling was high in pretreated rats, while only slightly increased in a few of the naïve rats. Necrotic hepatocytes were found at all time intervals in pretreated rats, and in naïve rats they appeared after 12 hr, peaking after 36 hr. Pretreatment increased the tolerance to acetaminophen toxicity twice, as estimated by mortality. The data indicate that pretreatment may reduce the relative production of toxic metabolites, but it primarily enhances the protection against these metabolites by regenerating hepatocytes.

GH decreases hepatic amino acid degradation after small bowel resection in rats without enhancing bowel adaptation.

Growth hormone (GH) treatment in short bowel syndrome is controversial, and the mechanisms of a possible positive effect remain to be elucidated. Rats were randomly subjected to either an 80% jejunoileal resection or sham operation and were given either placebo (NaCl) or biosynthetic rat GH (brGH). The in vivo capacity of urea nitrogen synthesis (CUNS) and the expression of urea cycle enzymes were measured and related to changes in body weight and adaptive growth in ileal segments on days 7 and 14. Ileal segments were examined by unbiased stereological techniques. brGH treatment decreased CUNS among the resected rats by 19% (P<0.05) and 36% (P<0.05) on days 7 and 14, respectively. The mRNA levels of urea cycle enzyme genes were not influenced by brGH treatment. brGH treatment did not increase the adaptive growth in the ileal segments. In conclusion, we found that GH treatment decreased the accelerated postoperative hepatic amino acid degradation in experimental short bowel syndrome without enhancing the morphological intestinal adaptation.

Prediction of hepatic encephalopathy in paracetamol overdose: a prospective and validated study.

BACKGROUND: Paracetamol overdose may cause hepatic encephalopathy (HE). This condition demands specialized care and, in some instances, liver transplantation evaluation. No model is available for predicting HE. We aimed to set up and validate a model for predicting the occurrence of HE in paracetamol overdose. METHODS: Prospectively, 161 patients with single-dose paracetamol overdose and no HE (defined as hepatic coma grade II or more) on admission were studied during a 26-month period. Patients admitted during the first 13-month period constituted a learning set to construct a model to predict the occurrence of HE. Patients admitted in the second 13-month period constituted the validation set. Serial biochemical variables (measured twice daily), the time line after the overdose, and demographic data were used for univariate testing, and significant factors were assessed in various multiple logistic regression analyses. RESULTS: Thirty-two patients (20%), 15 in the first period and 17 in the second, developed HE grade II. The best model (the highest chi-square) for HE included: log10 (hours from overdose to antidote treatment), log10 (plasma coagulation factors on admission), and platelet count hours from overdose (chi-square = 41.2, P < 0.00001). In the validation set 88% (confidence interval (CI), 64%-99%) of the patients who developed HE were correctly predicted by the constructed model, whereas 90% (CI, 79%-96%) of the patients in the non-HE group were correctly predicted. CONCLUSIONS: The constructed model for predicting HE in paracetamol overdose proved sensitive and accurate in the validation set and should be valuable for transferring high-risk patients to a liver intensive care unit/transplantation facility.

Effects of LPS on transport of indocyanine green and alanine uptake in perfused rat liver.

Lipopolysaccharide (LPS) initiates cholestasis. Whether this process is mediated by tumor necrosis factor-alpha (TNF-alpha) and whether the cholestatic response to LPS is associated with intrahepatic accumulation of possibly toxic substances are under debate. To study these questions the hepatic uptake and biliary excretion of indocyanine green (ICG) was examined in the isolated perfused rat liver 18 h after intravenous treatment of rats with either saline, 1 mg/kg body wt LPS, or LPS and intraperitoneal pentoxifylline (POF) (n = 6 in each group). POF inhibits TNF-alpha release after LPS administration. LPS induced a typical acute-phase response with increased mRNA for acute-phase proteins, reduced albumin mRNA, and increased hepatic uptake of alanine. Intrinsic hepatic clearance of ICG in controls (1.01 +/- 0.05 ml. min(-1). g liver(-1)) was similarly decreased by LPS alone (0.62 +/- 0.04 ml. min(-1). g(-1); P = 0.002 vs. control) or combined with POF (0.66 +/- 0.06 ml. min(-1). g(-1)). A kinetic analysis indicated that LPS reduced both uptake and excretion processes in a balanced manner, so that intrahepatic ICG content was unaffected or even slightly reduced, as confirmed by measurement of ICG contents in the perfused livers. In livers from parallel-treated nonperfused rats, mRNA for the organic anion transporting protein-1 (Oatp1, which is likely to mediate ICG uptake) was unaffected by LPS, whereas the concentration of Oatp1 protein was reduced. Thus LPS induced an acute-phase response that included downregulation of ICG uptake by reduction of Oatp1 protein concentration, possibly at a posttranscriptional level. TNF-alpha appears not to be the mediator because POF did not modify these LPS effects.

Reconstitution of the actin-scavenger system after orthotopic liver transplantation for end-stage liver disease: a prospective and longitudinal study.

Serum levels of the actin scavenger Gc-globulin (group-specific component, vitamin D-binding protein), a member of the albumin multigene family, are decreased in severe liver disease but have not been evaluated in relation to liver transplantation. We measured Gc-globulin and Gc-globulin-actin complex ratio daily for 2 weeks after transplantation in 17 patients with end-stage liver disease. Before transplantation, Gc-globulin levels were significantly less in the patients than in healthy controls (235 +/- 106 v 340 +/- 35 mg/L, respectively; P<.001), whereas complex ratio level was in the normal range. Five patients (group N) had pretransplantation Gc-globulin values within the normal range (mean +/- 2 SD), and 12 patients had subnormal values (group S). In group N, mean Gc-globulin levels posttransplantation remained stable at a lower level than before transplantation but still within normal range. In this group, cold ischemia time correlated inversely with Gc-globulin levels on day 2 (r = -0.88; P <.05). In group S, normal mean levels were reached at a mean of 11 days after transplantation. However, almost half these patients had subnormal Gc-globulin levels at day 14. Complex ratio levels remained normal in the study period in both groups. Prothrombin index levels (plasma coagulation factors II, VII, and X) were identical in both groups and returned to normal 7 days posttransplantation, whereas plasma albumin levels were less than normal in both groups and further decreased after transplantation. In conclusion, the maintenance (group N) or reestablishment (group S) of serum Gc-globulin to normal levels occurred in the early posttransplantation course in the same time frame as the prothrombin index. Gc-globulin synthesis seems unrelated to albumin synthesis. A prolonged cold ischemia time may cause reduced Gc-globulin levels early after transplantation.

Growth factors and gene expression in cultured rat hepatocytes.

BACKGROUND/AIM: The aim of this study was to evaluate the effect of replication on function variables in cultured hepatocytes. METHODS: Isolated rat hepatocytes were cultured in HCM medium and plated on collagen-coated dishes at cell densities from 0.2 x 10(5) (subconfluent) to 1.0 x 10(5) x cm(-2) (confluent) with and without addition of hepatocyte growth factor, epidermal growth factor and insulin-like growth factor-I. The synthesis rate was measured for DNA, albumin, urea, and glucose together with mRNA levels (Northern blots) for albumin, urea cycle enzymes, and acute phase and "house-keeping" proteins. RESULTS: In subconfluent culture the synthesis of DNA and urea was higher (118% and 112%, respectively), and of albumin and glucose lower (40% and 67%, respectively) than in confluent culture. The mRNA levels of carbamoylphosphate synthase, argininosuccinate synthetase, argininosuccinate lyase, arginase, a2-macroglobulin, beta-fibrinogen, and albumin were lower (23%, 58%, 77%, 33%, 12%, 50%, and 51%, respectively) in subconfluent culture compared with confluent culture. Relatively increased levels were found for beta-actin (109%) and alpha-tubulin (136%). In subconfluent culture hepatocyte growth factor increased the DNA synthesis rate 6-fold, epidermal growth factor 3-fold, and insulin-like growth factor-I 2-fold; that of albumin, urea and glucose was not increased significantly. In confluent culture the effect of growth factors on synthesis rates was not significant, and the growth factors had little influence on mRNA levels. CONCLUSIONS: Hepatocytes produce urea at the same rate in subconfluent as in confluent culture in spite of a lower mRNA level of urea cycle enzymes. Hepatocyte growth factor and epidermal growth factor increase DNA synthesis markedly in subconfluent culture only, without significantly changing the ratio between subconfluent and confluent culture of other variables. This suggests that active replication is not an important cause of the relatively low liver-specific function of hepatocytes in subconfluent culture.

Fine-resolution mapping by haplotype evaluation: the examples of PFIC1 and BRIC.

Loci for two inherited liver diseases, benign recurrent intrahepatic cholestasis (BRIC) and progressive familial intrahepatic cholestasis type 1 (PFIC1), have previously been mapped to 18q21 by a search for shared haplotypes in patients in two isolated populations. This paper describes the use of further haplotype evaluation with a larger sample of patients for both disorders, drawn from several different populations. Our assessment places both loci in the same interval of less than 1 cM and has led to the discovery of the PFIC1/BRIC gene, FIC1; this discovery permits retrospective examination of the general utility of haplotype evaluation and highlights possible caveats regarding this method of genetic mapping.

Hepatic blood flow and splanchnic oxygen consumption in patients with liver failure. Effect of high-volume plasmapheresis.

Liver failure represents a major therapeutic challenge, and yet basic pathophysiological questions about hepatic perfusion and oxygenation in this condition have been poorly investigated. In this study, hepatic blood flow (HBF) and splanchnic oxygen delivery (DO2, sp) and oxygen consumption (VO2,sp) were assessed in patients with liver failure defined as hepatic encephalopathy grade II or more. Measurements were repeated after high-volume plasmapheresis (HVP) with exchange of 8 to 10 L of plasma. HBF was estimated by use of constant infusion of D-sorbitol and calculated according to Fick's principle from peripheral artery and hepatic vein concentrations. In 14 patients with acute liver failure (ALF), HBF (1.78 +/- 0.78 L/min) and VO2,sp (3.9 +/- 0.9 mmol/min) were higher than in 11 patients without liver disease (1.07 +/- 0.19 L/min, P <.01) and (2.3 +/- 0.7 mmol/min, P <.001). In 9 patients with acute on chronic liver disease (AOCLD), HBF (1.96 +/- 1.19 L/min) and VO2,sp (3.9 +/- 2.3 mmol/min) were higher than in 18 patients with stable cirrhosis (1.00 +/- 0.36 L/min, P <.005; and 2.0 +/- 0.6 mmol/min, P <.005). During HVP, HBF increased from 1.67 +/- 0.72 to 2.07 +/- 1.11 L/min (n=11) in ALF, and from 1.89 +/- 1.32 to 2.34 +/- 1.54 L/min (n=7) in AOCLD, P <.05 in both cases. In patients with ALF, cardiac output (thermodilution) was unchanged (6.7 +/- 2.5 vs. 6.6 +/- 2.2 L/min, NS) during HVP. Blood flow was redirected to the liver as the systemic vascular resistance index increased (1,587 +/- 650 vs. 2, 020 +/- 806 Dyne. s. cm-5. m2, P <.01) whereas splanchnic vascular resistance was unchanged. In AOCLD, neither systemic nor splanchnic vascular resistance was affected by HVP, but as cardiac output increased from 9.1 +/- 2.8 to 10.1 +/- 2.9 L/min (P <.01) more blood was directed to the splanchnic region. In all liver failure patients treated with HVP (n=18), DO2,sp increased by 15% (P <.05) whereas VO2,sp was unchanged. Endothelin-1 (ET-1) and ET-3 were determined before and after HVP. Changes of ET-1 were positively correlated with changes in HBF (P <.005) and VO2,sp (P <.05), indicating a role for ET-1 in splanchnic circulation and oxygenation. ET-3 was negatively correlated with systemic vascular resistance index before HVP (P <.05) but changes during HVP did not correlate. Our data suggest that liver failure is associated with increased HBF and VO2, sp. HVP further increased HBF and DO2,sp but VO2,sp was unchanged, indicating that splanchnic hypoxia was not present.

Recurrent familial intrahepatic cholestasis in the Faeroe Islands. Phenotypic heterogeneity but genetic homogeneity.

Recurrent familial intrahepatic cholestasis is an autosomal recessive disorder characterized by episodes of severe pruritus and jaundice lasting for weeks to months without extrahepatic bile duct obstruction. Symptom-free intervals may last for months to years, and chronic liver damage does not develop. We recently studied four of the five patients from the Faeroe Islands described by us 30 years ago (one had recently died) and an additional five patients that were identified after the initial report. The episodes of cholestasis were more frequent and severe in patients with early onset, but tended to reduce in frequency with age. The youngest patient, aged 25 years, who had had 16 episodes each lasting about 6 months, had a liver transplant after which no further episodes were recorded (1 year after surgery). Signs of chronic liver disease were absent in all patients. The FIC1 gene was investigated for mutations in the surviving patients. A single mutation (I661T) was found on both chromosomes in all nine patients, indicating that they are genetically identical for the disease-causing defect. Nevertheless, considerable differences among patients were observed clinically.

[Recurrent familial intrahepatic cholestasis in the Faroe Islands]. / Recidiverende familiaer intrahepatisk kolestase på Faerøerne.

Recurrent familial intrahepatic cholestasis is an autosomal recessive disorder characterized by episodes of severe pruritus and jaundice lasting for weeks to months without extrahepatic bile duct obstruction. Symptom-free intervals may last for months to years, and chronic liver damage does not develop. We recently studied four of the five patients from the Faeroe Islands described by us 30 years ago (one had recently died), and a further five patients who were identified after the initial report. The episodes of cholestasis were more frequent and severe in patients with early onset, but tended to reduce in frequency with age. The youngest patient, aged 25 years, who had had 16 episodes, each lasting about six months, had a liver transplant after which no further episodes were recorded (one year after surgery). Signs of chronic liver disease were absent in all patients. The FIC1 gene was investigated for mutations in the surviving patients. A single mutation (I661T) was found on both chromosomes in all 9 patients, indicating that they are genetically identical for the disease causing defect. Nevertheless, considerable differences between patients were observed clinically.

Effects of growth hormone on steroid-induced increase in ability of urea synthesis and urea enzyme mRNA levels.

Growth hormone (GH) reduces the catabolic side effects of steroid treatment due to its effects on tissue protein synthesis/degradation. Little attention is focused on hepatic amino acid degradation and urea synthesis. Five groups of rats were given 1) placebo, 2) prednisolone, 3) placebo, pair fed to the steroid group, 4) GH, and 5) prednisolone and GH. After 7 days, the in vivo capacity of urea N synthesis (CUNS) was determined by saturating alanine infusion, in parallel with measurements of liver mRNA levels of urea cycle enzymes, N contents of organs, N balance, and hormones. Prednisolone increased CUNS (micromol . min-1 . 100 g-1, mean +/- SE) from 9.1 +/- 1.0 (pair-fed controls) to 13.2 +/- 0.8 (P < 0.05), decreased basal blood alpha-amino N concentration from 4.2 +/- 0.5 to 3.1 +/- 0.3 mmol/l (P < 0.05), increased mRNA levels of the rate- and flux-limiting urea cycle enzymes by 20 and 65%, respectively (P < 0. 05), and decreased muscle N contents and N balance. In contrast, GH decreased CUNS from 6.1 +/- 0.9 (free-fed controls) to 4.2 +/- 0.5 (P < 0.05), decreased basal blood alpha-amino N concentration from 3. 8 +/- 0.3 to 3.2 +/- 0.2, decreased mRNA levels of the rate- and flux-limiting urea cycle enzymes to 60 and 40%, respectively (P < 0. 05), and increased organ N contents and N balance. Coadministration of GH abolished all steroid effects. We found that prednisolone increases the ability of amino N conversion into urea N and urea cycle gene expression. GH had the opposite effects and counteracted the N-wasting side effects of prednisolone.

Hepatic plasma flow estimated according to Fick's principle in patients with hepatic encephalopathy: evaluation of indocyanine green and D-sorbitol as test substances.

The magnitude of hepatic plasma flow in patients with liver failure and hepatic encephalopathy (HE) is unknown because a reliable flow estimate has not been available. The purpose of this study was to estimate hepatic plasma flow in patients with HE and to evaluate indocyanine green (ICG) and sorbitol as test compounds. Fourteen patients with acute liver failure (ALF) and nine patients with chronic liver failure (CLF), all with HE grade II or more, were studied. After hepatic vein catheterization, hepatic plasma flow was estimated by use of constant infusion, simultaneous arterial and hepatic vein concentration measurements, and calculated according to Fick's principle. The hepatic extraction fraction of D-sorbitol 0.179+/-0.144 (mean+/-SD) was higher than the hepatic extraction fraction of ICG 0.054+/-0.085 (P < .001). The low hepatic extraction fraction of ICG rendered this compound unfit for estimation of hepatic plasma flow in these patients. In contrast, by using D-sorbitol the hepatic plasma flow could be estimated in 21 of 23 patients with a median SD of 8.4% (range, 2.6% to 29%). The D-sorbitol estimated hepatic plasma flow was 1.2+/-0.5 L/min (n = 12) in patients with ALF and 1.4+/-0.9 L/min (n = 9) in patients with CLF. These values are higher than what has been reported in normal subjects and in patients with cirrhosis without HE. An elevated hepatic flow should increase oxygen delivery and may enhance the failing liver's ability to remove substances from the blood. At the same time, hepatic first pass metabolism is reduced. We conclude that an elevated hepatic flow in these patients is of clinical importance.

Serum Gc-globulin in the early course of multiple trauma.

OBJECTIVES: In patients with multiple trauma, actin released from damaged cells may cause severe circulatory disturbance due to thrombi formation. The aim of this study was to evaluate serum concentrations of the actin scavenger, Gc-globulin, in relation to the severity of injury and outcome. DESIGN: Prospective, longitudinal, observational study. SETTING: Trauma center at a university hospital. PATIENTS: Twelve patients with multiple trauma, consecutively included, according to defined criteria. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Serum Gc-globulin concentrations were measured at the time of admission and daily thereafter for 1 wk or until death. In all patients, the Gc-globulin concentration was significantly low (p < .0001), and the proportion of Gc-globulin bound to actin was already increased compared with normal values (p < .0001) by the time of hospital arrival. There was an inverse correlation between the mean concentration of serum Gc-globulin in the first week after trauma and the Injury Severity Score (r = -0.72, p < .05). Surviving patients had a significantly (p < .05) higher concentration of serum Gc-globulin in the first week after trauma compared with nonsurvivors. CONCLUSIONS: Serum concentrations of Gc-globulin were significantly low in trauma patients. The reduction took place within 60 mins after injury. Because the normal half-life of Gc-globulin is almost 48 hrs, our observations suggest a marked consumption of Gc-globulin immediately after the trauma. This finding could be the first clinical evidence that Gc-globulin plays a role in the systemic inflammatory response syndrome after trauma. This result is supported by the finding that lack of Gc-globulin was related to nonsurvival and the severity of the trauma.