Infusion of ornithine-alpha-ketoglutarate in healthy subjects: effects on protein metabolism

Infusion of ornithine-alpha-ketoglutarate (Ornicetil) has been suggested to improve nitrogen balance in trauma patients. Whether this anticatabolic effect is localised to the liver or to skeletal muscle is as yet unknown. Consequently, the splanchnic and leg exchange of amino acids, urea and ammonia were measured in seven healthy non-obese subjects in the basal state and during infusion of ornithine-alpha-ketoglutarate at a rate of 28 mg/min for 150 min. The results demonstrate a six-fold rise in arterial ornithine and an increased uptake by both splanchnic and leg tissues during infusion. The splanchnic uptake of threonine and lysine also increased, while no other alterations were seen in leg amino acid exchange. The arterial urea concentration decreased slightly (-6%, P<0.01) during the infusion in spite of an unchanged urea production from the liver. The ammonia concentration fell by 20% (P<0.05), while glycerol and ketone body concentrations did not change significantly. It is concluded that intravenous infusion of ornithine-alpha-ketoglutarate in healthy subjects does not significantly influence hepatic or skeletal muscle protein metabolism.

Rapid effect of lansoprazole on intragastric pH: a crossover comparison with omeprazole

BACKGROUND

The time to onset of acid inhibition is considered an important factor when treating patients with reflux symptoms. This study was therefore designed to investigate the effect of 30 mg lansoprazole and 20 mg omeprazole on gastric pH after single-dose administration.

METHODS

The study was of a randomized, open-label, single-dose and two-way crossover design with a washout period of at least 7 days in between. Fifteen healthy adult male and female subjects were included. The subjects were intubated with a pH catheter. Intragastric pH was measured every 4th sec for 10 min before and during 8 h after drug administration. Blood samples, for determination of plasma concentrations of lansoprazole and omeprazole, were obtained on 10 occasions during 6 h after drug administration. The area under the curve (AUC), the elimination halflife (t1/2), and the peak concentration (Cmax) of the two drugs were calculated.

RESULTS

All subjects completed the study without major complications. The mean pH (0-8 h) after drug administration was 2.9 for lansoprazole and 2.0 for omeprazole (P = 0.0058). A pH of more than 4 was reached for the first time after 130 min with lansoprazole and after 250 min with omeprazole. AUC was 4919 +/- 2526 nmol/l x h for lansoprazole and 1352 +/- 1120 nmol/l x h for omeprazole.

CONCLUSION

Single-dose administration of 30 mg lansoprazole is followed by a rapid absorption of the drug and hence a more efficient acid suppression than after single-dose administration of 20 mg omeprazole in healthy volunteers.

Ursodeoxycholic acid treatment in patients with primary biliary cirrhosis. A Swedish multicentre, double-blind, randomized controlled study

BACKGROUND

Ursodeoxycholic acid (UDCA) has been shown to improve serum levels of liver enzymes and bilirubin in primary biliary cirrhosis (PBC). However, it is still uncertain whether UDCA treatment also improves symptoms, liver histology, and survival without liver transplantation.

METHODS

We randomized 116 patients with PBC to receive 0.5 g UDCA (n = 60) or placebo (n = 56) daily for 2 years. During the next 2 years, 80% of the UDCA-treated patients and 65% of the placebo-treated patients continued to take UDCA.

RESULTS

UDCA improved serum enzyme values but not survival, symptoms, serum bilirubin levels, or liver histology. There was no significant difference in response between initially symptomatic and asymptomatic patients.

CONCLUSIONS

UDCA in a dosage of 7.7 mg/kg body weight is of little benefit in PBC. This does not exclude the possibility that larger doses have beneficial effects.

Cyclophosphamide-induced acute liver failure requiring transplantation in a patient with genetically deficient debrisoquine metabolism: a causal relationship?

Severe liver damage can occur after treatment with cyclophosphamide. The possible linkage to genetically deficient drug metabolic capacity is unknown. A 58-year-old woman with rheumatoid arthritis was treated with oral cyclophosphamide 50 mg twice daily for 2 months. Due to poor response the dose was doubled and liver failure requiring transplantation developed within weeks. After surgery PCR amplification using DNA from leukocytes showed that she was homozygous for the mutated allele CYP2D6B, which is predictive of the poor metaboliser phenotype for debrisoquine, occurring in 7% of Caucasians. Our patient may have accumulated high levels of the hepatotoxic 4-hydroxylated cyclophosphamide metabolite. Pharmacogenetic methods can help in exploring mechanisms of unexpected severe adverse effects.

Primary sclerosing cholangitis and ulcerative colitis: evidence for increased neoplastic potential

Primary sclerosing cholangitis (PSC) is a biliary destructive disease mostly affecting patients with ulcerative colitis (UC). PSC has been suggested to be an independent risk factor for the development of colorectal malignancy in UC. Patients with PSC also have an increased risk of developing cholangiocarcinoma. This study aimed at assessing the cumulative risk of colorectal neoplasia in PSC and UC, and also to determine risk factors for the development of cholangiocarcinoma. Fifty-eight PSC patients were included. Forty PSC patients having extensive UC were each matched to two control patients of the same age, with extensive colitis and a comparable duration of the colitis, but without PSC. All UC patients had been under colonoscopic surveillance with multiple biopsies. Among the 40 PSC patients with UC, 16 developed colonic dysplasia or carcinoma, versus 10 in the control group (P < .001). The absolute cumulative risk of developing colorectal dysplasia/carcinoma in the PSC/UC groups was 9%, 31%, and 50% after 10, 20, and 25 years of disease duration. In the group with UC only, the corresponding risk was 2%, 5%, and 10%, respectively (P < .001). Ten patients with PSC developed cholangiocarcinoma, all but one having UC. In the control group, no cholangiocarcinoma occurred. Patients with PSC and UC with colorectal neoplasia developed cholangiocarcinoma significantly more often compared with patients with UC and PSC without colonic dysplasia/carcinoma (P < .02). This study demonstrates not only that patients with PSC and UC have a significantly higher risk of developing colorectal neoplasia compared with patients having UC only, but also that patients with PSC and UC having colorectal neoplasia are more prone to develop cholangiocarcinoma.

Influence of orthotopic liver transplantation on serum vitamin A levels in patients with chronic liver disease

BACKGROUND

Low serum vitamin A levels are observed in many liver diseases, such as primary biliary cirrhosis (PBC) and alcoholic liver disease. The aim of this study was to investigate serum vitamin A in patients with advanced liver diseases before and after orthotopic liver transplantation (OLT).

METHODS

Serum vitamin A (retinol) concentrations were investigated in 54 patients before (OLT) and in 21 patients 1, 2, 3, and 4 weeks and 2 and 3 months after OLT. Ten healthy subjects and 19 patients with inflammatory bowel disease (IBD) served as control groups.

RESULTS

The mean serum retinol concentration before OLT was 0.64 +/- 0.1 mumol/l in patients with alcoholic and postnecrotic cirrhosis (n = 24), 1.06 +/- 0.48 mumol/l in patients with PBC (n = 14), 0.96 +/- 0.64 mumol/l in sclerosing cholangitis (n = 7), and 1.02 +/- 0.73 mumol/l in liver cancer (n = 9). These results were significantly lower than in healthy controls (2.34 +/- 0.54 mumol/l) and patients with IBD (2.7 +/- 0.74 mumol/l) (p < 0.001).

CONCLUSIONS

After OLT, serum retinol levels increased significantly already after 1 week (1.4 +/- 0.1 mumol/l) (p < 0.001), normalized after 2 weeks (2.2 +/- 0.4 mumol/l), and remained normal during the observation.

Ventilation-perfusion relationships and central haemodynamics in patients with cirrhosis. Effects of a somatostatin analogue

The ventilation-perfusion relationships of the lung (VA/Q) and central haemodynamics were studied in seven patients with cirrhosis before and 30 min after a bolus injection of a somatostatin analogue, octreotide (Sandostatin, 50 micrograms i.v.), to elucidate the role of this substance in the hepatopulmonary syndrome. In the basal state all patients had normal spirometry but reduced diffusing capacity. Three patients had various degrees of hypoxaemia (6.9-8.3 kPa) and three had clubbing of the fingers. In the basal state VA/Q distributions, determined by inert gas elimination technique, showed an intrapulmonary shunt of 7.9 +/- 2.2% of cardiac output (range 1.5 to 17.1) and perfusion of lung regions with "low VA/Q" of 4.4 +/- 2.2% of cardiac output (range 0 to 15.4). After octreotide, the amount of shunting increased (10.9 +/- 4.4% of cardiac output; non-significant), while "low VAQ" was unchanged (3.7 +/- 1.3% of cardiac output). Arterial oxygen tension decreased from 10.2 +/- 1.1 to 9.7 +/- 1.1 kPa (non-significant). The mean pulmonary arterial pressure increased from 14.5 +/- 1.9 to 16.3 +/- 1.8 mmHg (p < 0.01). No alterations were seen in heart rate, stroke volume, cardiac output, central pressures or vascular resistances. The results of the present study do not support the hypothesis that octreotide improves hypoxaemia and ventilation-perfusion relationships in patients with hepatopulmonary syndrome.

Cancer risk in primary biliary cirrhosis: a population-based study from Sweden

A cohort of 559 patients in Sweden who satisfied predetermined criteria for the diagnosis of primary biliary cirrhosis was followed with respect to the incidence of cancer during the period of 1958 to 1988. The mean follow-up time from the time of primary biliary cirrhosis diagnosis was 9.0 +/- 5.4 yr. During the follow-up period, 148 patients died and the primary cause of death was liver insufficiency. An overall excess risk for cancer, standardized incidence ratio 1.6; 95% confidence interval, 1.1 to 2.2, was found in the cohort. In contrast to previous reports, we found no excess risk for breast cancer (standardized incidence ratio, 0.9; 95% confidence interval, 0.3 to 2.1). The number of hepatocellular cancers in the primary biliary cirrhosis cohort did not significantly differ from expected (standardized incidence ratio, 2.91; 95% confidence interval, 0.4 to 10.5).

Splanchnic and peripheral glucose metabolism in cirrhosis

The effects of glucose and insulin administration on splanchnic and leg exchange of glucose were investigated in seven patients with cirrhosis and six sex- and age-matched healthy controls using the catheter technique. After a basal period, glucose infusion (1 mg.kg-1.min-1) was given for 45 min, followed by a 2-h euglycemic insulin clamp (1 mU.kg-1.min-1). In the basal state insulin levels were significantly higher in patients than in controls (25 +/- 4 vs. 7 +/- 2 microU/ml). Net splanchnic glucose output tended to be lower in patients than in controls (0.50 +/- 0.16 vs 0.73 +/- 0.11 mmol/min nonsignificant), as did leg glucose uptake (0.06 +/- 0.01 vs 0.08 +/- 0.02 mmol/min, non-significant). Glucose infusion resulted in a significant rise in leg glucose uptake, while net splanchnic glucose output decreased in both groups. During the euglycemic insulin clamp, insulin concentrations rose to 110 +/- 10 and 80 +/- 8 microU/ml in patients and controls, respectively. C-peptide concentrations decreased in the healthy controls but were unchanged from the basal level in patients with cirrhosis. Glucose disposal during the last half hour of the clamp was 1.12 +/- 0.08 and 3.19 +/- 0.04 mmol/min in patients and controls, respectively (p < 0.001). Glucose was taken up by the splanchnic region in both groups but this uptake was significantly greater in patients than in controls (0.42 +/- 0.05 vs. 0.25 +/- 0.06 mmol/min, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment for liver transplantation in patients with primary sclerosing cholangitis

Recently three large studies have been presented in which the prognostic significance of clinical, laboratory and histological parameters measured early in the course of the disease was determined in primary sclerosing cholangitis patients. A different prognostic index was presented in each study. The aim of the present study was to evaluate these prognostic indices in a group of 37 patients with primary sclerosing cholangitis, assessed for liver transplantation. The results are compared to the outcome in the patients. At first referral, 12 patients were considered too healthy for transplantation and 17 were accepted for transplantation, six of whom died during the waiting time. Ten patients had cholangiocarcinoma or hepatocellular cancer. Albumin and bilirubin differed significantly between the patients accepted for transplantation and those considered too healthy. Only one prognostic index, presented by Dickson et al., could discriminate between "too healthy" and "in need of transplantation". However, the overlap between the groups was large, suggesting that this index may be of little or no help in the clinical situation with individual patients. Moreover, neither the prognostic index, nor any of the laboratory values could identify the patients with cancer. It is concluded that prognostic indicators have been found that may help to characterise primary sclerosing cholangitis patients. However, primary sclerosing cholangitis patients with an accompanying cholangiocarcinoma still cannot be identified.

Insulin action on glucose transport in isolated skeletal muscle from patients with liver cirrhosis

Insulin resistance, associated with liver cirrhosis, has been suggested to be localized in skeletal muscle. We used an in vitro incubation technique to determine insulin action on glucose transport in skeletal muscle obtained from seven patients with clinically stable alcoholic cirrhosis and seven healthy age- and sex-matched individuals. In addition, a euglycemic-hyperinsulinemic clamp procedure was performed to assess whole-body insulin-mediated glucose uptake. Insulin-mediated peripheral glucose utilization was 40% lower (p < 0.05) in the cirrhotic patients than in the healthy individuals. Intact skeletal muscle from the vastus lateralis portion of the quadriceps femoris muscle was obtained from each study participant. Thereafter, smaller skeletal muscle strips (approximately 18 mg) were dissected free and incubated in vitro to assess the rate of non-insulin- and insulin-stimulated 3-O-methylglucose transport. Insulin increased the rate of 3-O-methylglucose transport in a dose-dependent manner, with a maximal response observed in the presence of 200 microU/ml in skeletal muscle obtained from the cirrhotic patients and healthy individuals. The dose-response curve for insulin-stimulated 3-O-methylglucose transport did not differ between the groups. Furthermore, muscle glycogen content of needle biopsy specimens was comparable in the two groups. In conclusion, the present group of patients, with liver cirrhosis on an alcoholic basis, had a normal insulin-stimulated capacity for glucose transport at the cellular level irrespective of the degree of whole-body insulin resistance. The mechanism for the divergence between the in vivo and in vitro responses to insulin remains to be elucidated.

Influence of insulin on glucose metabolism and lipolysis in adipose tissue in situ in patients with liver cirrhosis

The influence of insulin on lipolysis and glucose metabolism in abdominal adipose tissue was studied in situ with the microdialysis technique during a euglycaemic insulin clamp (1 mU kg-1 min-1) in nine cirrhotic patients and 10 controls. The cirrhotic patients displayed a 50% decrease in glucose utilization rate during the clamp (P < 0.001). Dialysate glucose levels decreased similarly by 20-30%., in patients and controls, which in the presence of unchanged local blood flow in the adipose tissue in response to insulin, is at hand with a glucose uptake into the adipocytes of similar magnitude in both groups. Before and during the clamp, the arterial and dialysate levels of glycerol were higher in the patients than in the control subjects (ANOVA P = 0.001 and 0.048 in arterial blood and dialysate, respectively). In relative terms, however, insulin induced a 70% reduction of arterial and dialysate glycerol in both groups. The concentrations of lactate and pyruvate in the dialysate and blood increased in a similar way in both groups during hyperinsulinaemia. The results suggest an increased rate of lipolysis in cirrhotic patients. Insulin cannot lower it to normal, although it is still capable of achieving a relative reduction. No explanation was found in the adipose tissue to the insulin resistance to whole-body glucose utilization that was noted in the patients with cirrhosis.

A simplified method to determine galactose elimination capacity in patients with liver disease

Galactose elimination capacity (GEC) is one of the most widely used liver function tests. It is relatively simple but still involves a number of capillary blood samples and is therefore fairly expensive. In the current study we present a simplified formula, based on GEC investigations in 103 cirrhotic patients, with which it is possible to estimate the GEC with one or two blood samples. Using this formula: GEC = [7.422--corrected B-galactose60 min]/4.575, we could accurately predict GEC in 24 additional patients.

Effect of vasoactive intestinal polypeptide (VIP) on pulmonary ventilation-perfusion relationships and central haemodynamics in healthy subjects

Ventilation-perfusion relationships of the lung (VA/Q) and central haemodynamics were studied in nine healthy subjects before and during 30 min of vasoactive intestinal polypeptide (VIP) infusion (20 ng kg.min-1). During the infusion, arterial concentrations of VIP rose from 16.1 +/- 6.1 to 420 +/- 110 pmol l-1 and noradrenaline concentrations doubled (P < 0.01). VA/Q distributions, determined by inert gas elimination technique, were significantly shifted to lower values for VA/Q with slight increases in dispersions, but arterial oxygen tension remained unchanged. Heart rate, stroke volume and cardiac output rose 27, 44 and 80% respectively (P < 0.01). Systematic arterial pressure stabilized at a slightly lower level compared to basal (base line: 93 +/- 5 mmHg, VIP; 88 +/- 6 mmHg, P < 0.05). Right atrial and pulmonary capillary wedge pressures remained unchanged during VIP infusion, while pulmonary vascular resistance and systematic vascular resistance decreased significantly, by 25% (P < 0.03) and 53% (P < 0.01), respectively. It is concluded that VIP causes: (1) alterations in ventilation-perfusion distributions, but generates no shunt and does not cause hypoxaemia during 30 min infusion, (2) reduction of pulmonary and systemic vascular resistances and afterload reduction of the left ventricle, (3) reflex sympathoadrenal stimulation with increasing heart rate and myocardial contractility, and (4) a direct positive inotropic effect on the myocardium.

Influence of insulin on peripheral uptake of branched chain amino acids in the 60-hour fasted state

The influence of insulin on branched chain amino acid (BCAA) metabolism was investigated in healthy subjects faster for 60-64 h, using the euglycemic insulin clamp technique and hepatic venous catheterization. As compared to the postabsorptive state, fasting resulted in a 50-80% decrease in glucose disposal during the clamps, indicating insulin resistance. However, the arterial concentrations of BCAA, which were increased by 200-220% after the fast, decreased to a similar extent during hyperinsulinemia, regardless of the fasting situation. The splanchnic exchange of BCAA was unaltered both in response to fasting itself and to fasting and hyperinsulinemia. The results suggest that insulin resistance during fasting does not influence BCAA metabolism. Furthermore, the changes in BCAA concentrations after a prolonged fast are due to altered peripheral metabolism of BCAA.

Influence of beta blockade on branched chain amino acid concentrations in cirrhosis

Cirrhosis of the liver is typically accompanied by low plasma levels of the three branched chain amino acids (BCAA). These patients also demonstrate increased concentrations of several hormones such as insulin, glucagon and catecholamines. Catecholamines have been shown to influence the plasma levels of amino acids in healthy subjects and diabetics. In the present study, amino acid concentrations were investigated before and up to 3 hours after beta blockade (Inderal, 40-80 mg, n = 10) or fasting (n = 8) in cirrhotic patients. In the basal state the patients had low levels of all three BCAA, as compared with healthy subjects. Norepinephrine was more than 3 times as high in the patients (3.65 +/- 0.6 vs. 0.84 +/- 0.08 nmol/l, p < 0.01) while epinephrine was only slightly raised (0.43 +/- 0.1 vs. 0.25 +/- 0.06 nmol/l, NS). Significant correlations were observed between the concentrations of norepinephrine and individual as well as the sum of the three BCAA (r = 0.43-0.62, p < 0.05-0.001), while no correlation was observed between the BCAAs and epinephrine or insulin. Three hours after beta blockade the concentrations of leucine (basal: 74 +/- 6, 180 min: 89 +/- 6 mumol/l, p < 0.05) and valine (basal: 110 +/- 10, 180 min: 132 +/- 11 mumol/l, p < 0.01) had increased significantly. A similar tendency was observed for isoleucine. No changes were observed after prolonged fasting. The results suggest that catecholamines, primarily norepinephrine, might contribute to the low levels of BCAA in cirrhotics.

Effect of insulin on human adipose tissue metabolism in situ. Interactions with beta-adrenoceptors

The effects of insulin, and its interactions with catecholamines through beta-adrenoceptors, on human adipose tissue glucose utilization and lipolysis were investigated in vivo. Microdialysis of the extracellular compartment of abdominal subcutaneous adipose tissue was performed in healthy subjects of normal weight, before and during a 2-h hyperinsulinaemic (61 +/- 3 mU/l), euglycaemic clamp. The tissue was perfused with or without the beta-adrenergic agonist isoproterenol (10(-6) mol/l), and the tissue dialysate concentrations of glucose, glycerol (lipolysis index) lactate and pyruvate were determined. During the insulin infusion, glucose in adipose tissue decreased by 20% (p less than 0.001), despite arterial steady-state normoglycaemia. The concentrations of lactate and pyruvate increased gradually to a steady-state plateau of twice the basal level in adipose tissue and arterial blood. Insulin-induced suppression of glycerol (lipolysis index) was, if anything, more marked in adipose tissue than in plasma (65% vs 50% decrease from baseline levels, p less than 0.05). In situ perfusion of adipose tissue with isoproterenol, starting either at the beginning of the study period or at 45 min after initiation of the insulin infusion, resulted in marked and rapid elevations of all the investigated metabolites in the adipose tissue extracellular compartment (p less than 0.05-0.005). It is concluded that insulin action on glucose uptake and lipolysis in human adipose tissue in vivo is counteracted by beta-adrenoceptor stimulation. In contrast, insulin and beta-adrenoceptors have synergistic effects on non-oxidative glucose metabolism in human adipose tissue in situ.

Hepatotoxicity due to repeated intake of low doses of paracetamol

The cases of two patients with fulminant hepatic failure after intake of therapeutic doses (4-8 g) of paracetamol, and who were admitted to hospital for assessment for liver transplantation, are described. In both patients starvation, due to abdominal pain, nausea and vomiting or diarrhoea, was probably contributing to the toxic effect of the drug. One of the patients also had an excessive alcohol intake. Paracetamol should not be prescribed for patients with alcoholism or with low food intake.

Decreased in vitro production of tumor necrosis factor in primary biliary cirrhosis patients

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are characterized by immunoregulatory disturbances and fibrosis. Several cytokines may be of importance for the inflammatory response and the development of fibrosis. In the present study the capacity to produce tumor necrosis factor (TNF) and interleukin-1 (IL-1) was determined in 11 patients with PSC, 10 patients with PBC, and 20 healthy control subjects. As compared with the controls, in vitro cultured mononuclear cells from PBC patients showed a lower spontaneous TNF production (median, 16,499 cpm; range, 7181-41,907; p less than 0.02), whereas the TNF production of PSC patients was similar to that of the controls. Lipopolysaccharide (LPS)-stimulated TNF production was also lower in the PBC group (median, 40,564 cpm; range, 23,493-69,452) than in PSC patients (median, 58,898 cpm; range, 37,997-91,485; p less than 0.03). The spontaneous and LPS-stimulated IL-1 production did not differ in patients and healthy controls. The cytokine production in patients with PBC and PSC did not correlate to histologic activity, associated diseases such as ulcerative colitis and bilirubin, or to Child-Pugh classification. Thus, in contrast to hepatocellular diseases, in which cytokine production is reported to be increased, PBC and PSC are accompanied by low or normal TNF and IL-1 production.

Ventilation-perfusion inequality in patients with non-alcoholic liver cirrhosis

Ventilation-perfusion relationships were studied in patients with non-alcoholic liver cirrhosis. Spirometry was essentially normal but the transfer factor of the lung (DLCO) was reduced by an average 34% of predicted. Arterial oxygen tension (PaO2) ranged from normal down to 6.9 kPa. Varying degrees of ventilation-perfusion (VA/Q) abnormalities (multiple inert gas elimination technique) were observed with increased dispersion of the perfusion distribution (log SDQ, 0.90; range 0.32-1.71; upper normal limit, 0.60) and the presence of both regions of low VA/Q ratios (between 0.1 and 0.005) (mean 4.1%; range 0-18.8%) and shunt (VA/Q ratios below 0.005) (mean 3.9%; range 0.19.8%). There was a close similarity between measured and calculated PaO2 in normoxaemic patients, but calculated values exceeded measured PaO2 in hypoxaemic patients. The difference between calculated and measured PaO2 correlated inversely to DLCO (r = 0.65, p less than 0.05). An inverse correlation was also noted between DLCO and the sum of shunt and low VA/Q regions (r = 0.87, p less than 0.001). It is concluded that hypoxaemia in non-alcoholic liver cirrhosis patients can be accounted for by intrapulmonary shunting and VA/Q mismatch, and possibly a "diffusion-perfusion" defect in patients with more severe gas exchange impairment.

Ventilation-perfusion inequality in patients with non-alcoholic liver cirrhosis

Ventilation-perfusion relationships were studied in patients with non-alcoholic liver cirrhosis. Spirometry was essentially normal but the transfer factor of the lung (DLCO) was reduced by an average 34% of predicted. Arterial oxygen tension (PaO2) ranged from normal down to 6.9 kPa. Varying degrees of ventilation-perfusion (VA/Q) abnormalities (multiple inert gas elimination technique) were observed with increased dispersion of the perfusion distribution (log SDQ, 0.90; range 0.32-1.71; upper normal limit, 0.60) and the presence of both regions of low VA/Q ratios (between 0.1 and 0.005) (mean 4.1%; range 0-18.8%) and shunt (VA/Q ratios below 0.005) (mean 3.9%; range 0.19.8%). There was a close similarity between measured and calculated PaO2 in normoxaemic patients, but calculated values exceeded measured PaO2 in hypoxaemic patients. The difference between calculated and measured PaO2 correlated inversely to DLCO (r = 0.65, p less than 0.05). An inverse correlation was also noted between DLCO and the sum of shunt and low VA/Q regions (r = 0.87, p less than 0.001). It is concluded that hypoxaemia in non-alcoholic liver cirrhosis patients can be accounted for by intrapulmonary shunting and VA/Q mismatch, and possibly a "diffusion-perfusion" defect in patients with more severe gas exchange impairment.

Normalization of ventilation/perfusion relationships after liver transplantation in patients with decompensated cirrhosis: evidence for a hepatopulmonary syndrome

To examine the effect of liver transplantation on the respiratory and cardiovascular functions, ventilation/perfusion relationships were determined by multiple inert gas elimination technique in six patients with end-stage liver disease 1 to 19 mo before and 2 to 6 mo after liver transplantation. Cardiac output and pulmonary vascular pressures were measured after catheterization of the pulmonary artery. All patients had normal spirometry and chest x-ray films before transplantation. PaO2 before transplantation was 78.8 +/- 7.4 mm Hg (range = 51.8 to 102.8 mm Hg). All patients had perfusion of poorly ventilated lung regions (low ventilation/perfusion relationships) varying from 3% to 19% of cardiac output (mean = 8.5% +/- 2.4% of cardiac output) and two patients had intrapulmonary shunting (3% and 20% of cardiac output). Measured and calculated PaO2 agreed closely, indicating absence of pulmonary diffusion abnormality, as well as of extrapulmonary shunting. After transplantation, PaO2 normalized in all patients, and both shunting and low ventilation/perfusion relationships disappeared. Cardiac output decreased from 9.1 +/- 1.4 to 6.6 +/- 0.5 L/min (p less than 0.05), and the pulmonary vascular resistance increased from 0.69 +/- 0.14 to 1.64 +/- 0.43 mm Hg/L/min (p less than 0.05). The systemic vascular resistance also increased (before = 8.7 +/- 1.0; after = 15.3 +/- 1.1 mm Hg/L/min; p less than 0.001). Normalization of respiratory and cardiovascular alterations, after liver transplantation, in patients with end-stage liver disease indicates that these changes have a direct functional relationship to the diseased liver. It is hypothesized that this is part of a "hepatopulmonary syndrome,' which in similarity to the hepatorenal syndrome disappears with improved liver function.

Anesthesia for liver transplantation in patients with arterial hypoxemia

Arterial oxygenation during anesthesia and time of postoperative mechanical ventilation were investigated in 17 patients with chronic liver disease who underwent liver transplantation. Six patients had arterial hypoxemia (PaO2 64 +/- 3 mm Hg) and the other 11 patients had normal PaO2 (105 +/- 5 mm Hg) before transplantation. None of the patients were smokers and all had normal preoperative pulmonary X-ray and spirometry. During transplantation, PaO2 increased in both groups, but PaO2 was still approximately 20% lower and PA-aO2 was 40%-60% higher in the hypoxemic group than in the normoxemic patients (P less than 0.05). The median postoperative time on mechanical ventilation was three times longer in the hypoxemic group (56 h) than in the normoxemic patients (18 h; P = NS). Number or severity of postoperative complications and outcome did not differ between the two groups. It is therefore suggested that patients with arterial hypoxemia without overt lung disease should also be accepted for liver transplantation.

Influence of leucine infusion on intracellular amino acids in humans

A continuous intravenous infusion of L-leucine (300 mumols min-1) was given to 12 healthy females over a 2 1/2 h period. Arterial plasma concentrations of amino acids and the keto acids of the branched-chain amino acids (BCAA) were measured. In six subjects muscle biopsies were taken before and at the end of the infusion for determination of intracellular (i.c.) free amino acid concentrations, and leg exchange of amino acids was measured. During infusion the plasma level of leucine rose sixfold. Approximately 40% of the infused amount was taken up by muscle. Of this, half was accumulated intracellularly, where the free leucine concentration increased from basal 190 +/- 22 to 580 +/- 110 mumols l-1 ICW (intracellular water) at the end of infusion. The concentrations of most other amino acids, above all the other BCAA and the aromatic amino acids, decreased, by 17-48% in the i.c. pool and by 17-79% in plasma. The plasma level of ketoisocaproic acid (KIC), the keto acid of leucine, increased in parallel with that of leucine. The concentration of keto valine, ketoisovaleric acid (KIV), decreased by 75%, whereas the keto acid of isoleucine, ketomethylvaleric acid (KMV), was unchanged. Leg release of alanine decreased significantly, whereas the exchange of other amino acids were unchanged. Taken together, decreased i.c. and plasma concentrations but unchanged leg exchange of tyrosine and phenylalanine suggest i.c. accumulation of protein. It can be calculated that approximately 40% of the leucine taken up by muscle was accumulated in the intracellular free pool, some 20% could have been incorporated into protein and 40% was probably oxidized.

Gut exchange of glucose and lactate in basal state and after oral glucose ingestion in postoperative patients

Glucose uptake by the intestine and its conversion into 3-carbon compounds in the human intestine in the basal state and after an oral glucose load are not understood. Consequently, we studied the arterial and portal venous concentration differences (A-PV) for glucose and glucogenic substrates in the basal state and 3 h after the ingestion of a 100-g glucose load with the catheter technique. Five patients were studied 3-11 days after surgery for gallbladder disease or cancer of the colon or liver. A-PV for glucose in the basal state was 0.12 +/- 0.02 mM (P less than 0.01), indicating net glucose uptake by extrahepatic splanchnic tissues. No net exchange of lactate or pyruvate was detected, but there was release of alanine and uptake of glutamine. After glucose ingestion, glucose was released by the gut, reflecting absorption of the load (mean A-PV for glucose -2.10 +/- 0.04 mM, P less than 0.01). The arterial glucose concentration rose gradually from 4.6 +/- 0.1 mM before glucose ingestion to a plateau at 9.5 +/- 0.7 mM from 90 to 180 min. Glucose ingestion was accompanied by net lactate and alanine release (A-PV -0.16 +/- 0.06 mM and -48 +/- 7 microM, respectively), whereas A-PV for pyruvate did not change. We conclude that, in postoperative patients, there is a significant net glucose uptake by the gastrointestinal tract in the basal state. Glucose ingestion is accompanied by a small release of lactate and alanine from the intestine. However, the estimated net gut formation of lactate and alanine can play only a minor role in the disposal of an oral glucose load.

Hypoxemia in patients with liver cirrhosis

Chronic liver disease is often accompanied by alterations in the pulmonary and cardiovascular systems as demonstrated by hypoxemia, hyperkinetic circulation and impaired pulmonary and systemic vascular resistance. In some patients these abnormalities are due to ventilation-perfusion imbalance and/or intrapulmonary shunting. Although the pathogenesis of these disturbances is unknown it can be hypothesized that vasodilating substances might bypass the liver and give rise to such changes in intrapulmonary vessels. The normalization of pulmonary perfusion after liver transplantation suggests a direct functional relationship between the liver and the lungs--a "hepatopulmonary syndrome"--similar to the functional renal failure widely known as the hepatorenal syndrome.

Visual evoked potential--a tool in the diagnosis of hepatic encephalopathy?

Visual evoked potentials (VEP) have been suggested to be of value in the diagnosis of subclinical and mild hepatic encephalopathy. In the present study, a comparison between VEP and four psychometric tests (number connection test A and B, digit symbol and word memory test) was performed in 42 cirrhotic patients, 17 of whom had clinical signs of encephalopathy. The results were compared to sex- and age-matched healthy controls. The VEP latencies for P2 (the second positive wave) and N3 (the third negative wave) were 11% and 26% longer (P less than 0.01-0.001) in the patients than in the controls. Moreover, the latencies for N2 (the second negative wave) and P2 were longer in the encephalopathic as compared to the non-encephalopathic patients (P less than 0.05). There was a significant correlation between the latencies for N2 and number connection tests A and B and digit symbol test. However, of the patients with clinical encephalopathy, less than half had VEP latencies longer than the mean +/- 2 S.D. above those for the controls. In contrast, none of the encephalopathic patients had normal results on the psychometric tests. This study demonstrates that although statistically significant differences exist between groups of cirrhotic patients and controls, VEP is not a reliable tool for the diagnosis of encephalopathy in the individual patient.

Intravenous and subcutaneous administration of a long-acting somatostatin analogue: effects on glucose metabolism and splanchnic haemodynamics in healthy subjects

The effect of SMS 201-995, a long-acting somatostatin analogue, on splanchnic blood flow and glucose metabolism, was investigated in five groups of healthy subjects. Groups A (n = 4), B (n = 5), C (n = 5) and D (n = 5) were studied before, during and after a 60-min intravenous infusion of SMS (1.7, 0.8, 0.2 and 0.1 micrograms min-1, respectively). Group E (n = 6) was investigated before and for 6 h after a subcutaneous injection of 25 micrograms of SMS. The splanchnic blood flow decreased by 20-25% in all groups in response to SMS and remained low during the entire observation periods. Arterial concentrations of glucose showed a 15-20% decline during SMS infusion in Groups A and B (P less than 0.05-0.01) and a less pronounced decrease in the other groups. Fifteen minutes after the end of infusion the glucose levels started to rise and in group A, the levels were significantly higher than basal (+25%, P less than 0.05-0.01) at 90-180 min after the end of infusion. The net splanchnic glucose production, determined in groups A and B, decreased by 65-75% in response to SMS infusion. Towards the end and immediately after the infusions, however, the net glucose output increased, but decreased again at 30-60 min after the end of infusion. Arterial, insulin and glucagon concentrations decreased significantly during infusion in all groups. This decline was more pronounced for insulin (50%) than for glucagon (20-25%) and insulin concentrations remained low for a longer period after the end of infusions.(ABSTRACT TRUNCATED AT 250 WORDS)

Diet-induced thermogenesis in patients with liver cirrhosis

Diet-induced thermogenesis after ingestion of a mixed meal was investigated in eight patients with documented liver cirrhosis and in eight age- and sex-matched healthy controls. Respiratory gas exchange was measured continuously for one hour in the basal state and for three hours after ingestion of a mixed liquid meal, consisting of 17% kJ protein, 28% kJ lipids and 55% kJ carbohydrates and dispensed to correspond to 60% of the individually computed energy expenditure. Arterial substrate and hormone concentrations were determined before and at timed intervals for three hours after the meal. Urine was collected for determination of nitrogen excretion. The patients' oxygen uptake, energy expenditure and respiratory quotient were similar to those of the controls in the basal state. After the meal, pulmonary oxygen uptake and energy expenditure rose markedly in both groups during the first hour and were subsequently stable. The average increase in oxygen uptake above basal during the whole study period was 21.2 +/- 1.8% and 22.3 +/- 1.2% (NS) in patients and controls, respectively. The corresponding increase in energy expenditure was 24.8 +/- 2.0% in the patients and 24.9 +/- 1.4% in the controls (NS). The respiratory quotient was elevated throughout the postprandial period in both groups but the quotient was significantly higher in the patients (P less than 0.05-0.001), suggesting a greater proportion of carbohydrate oxidation. The basal arterial concentrations of insulin and glucagon were significantly higher in the patients. After the meal the insulin level increased 10- to 20-fold in both groups. Glucose concentration rose significantly in both groups to a maximum of 8.82 +/- 1.00 and 8.03 +/- 0.95 mmol/l in patients and controls, respectively, at 60 min after the meal. This was accompanied by a fall in the levels of glycerol and ketone bodies in both groups, indicating decreased lipolysis. It is concluded that both the basal energy expenditure and the thermogenic response to a mixed meal are similar in patients with liver cirrhosis and in healthy controls. The patients' carbohydrate oxidation rose to a greater extent after the meal, probably as a consequence of excessive increases in insulin concentration, demonstrating that insulin resistance in these patients may be compensated for by postprandial hyperinsulinaemia.

Influence of vasoactive intestinal polypeptide (VIP) on splanchnic and central hemodynamics in healthy subjects

The influence of VIP, a potent vasodilator, on central hemodynamics, splanchnic blood flow and glucose metabolism was studied in six healthy subjects. Teflon catheters were inserted into an artery, a femoral vein and a right-sided hepatic vein. A Swan-Ganz catheter was introduced percutaneously and its tip placed in the pulmonary artery. Determinations of cardiac output, systemic, pulmonary arterial and hepatic venous pressures as well as splanchnic blood flow were made in the basal state and at the end of two consecutive 45 min periods of VIP infusion at 5 and 10 ng/kg/min, respectively. Arterial blood samples for analysis of glucose, FFA, insulin and glucagon were drawn at timed intervals. VIP infusion at 5 ng/kg/min resulted in an increase in cardiac output (55%) and heart rate (25%) as well as a reduction in mean systemic arterial pressure (15%) and vascular resistance (45%). With the higher rate of VIP infusion heart rate tended to rise further while cardiac output and arterial pressure remained unchanged. At 15 min after the end of VIP infusion the above variables had returned to basal levels. Splanchnic blood flow and free hepatic venous pressure did not change significantly. Arterial concentrations of glucose, FFA, insulin and glucagon increased during VIP infusion. At 15 min after the end of infusion the glucose levels were still significantly higher than basal (20%). Net splanchnic glucose output did not change in response to VIP infusion. It is concluded that VIP exerts a potent vasodilatory effect resulting in augmented cardiac output and lowered systemic blood pressure and vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Splanchnic metabolism of amino acids in healthy subjects: effect of 60 hours of fasting

Brief starvation is accompanied by decreased circulating levels of most amino acids, which has been attributed to an increased splanchnic uptake of amino acids, primarily alanine, for gluconeogenesis. However, quantitative data on splanchnic exchange of amino acids and gluconeogenic precursors is lacking. Consequently, arterial concentrations and splanchnic exchange of whole blood amino acids, ketone bodies, glucose, and gluconeogenic precursors were measured in 16 prolonged fasted (60 to 64 hours) and 15 overnight fasted (12 to 14 hours) healthy, nonobese subjects. After the 60-hour fast net splanchnic glucose production decreased by 41% to 0.31 +/- 0.02 mumol/L (P less than .001), whereas the splanchnic uptake of gluconeogenic precursors increased and could account for the total glucose output. Net splanchnic uptake of taurine, threonine, serine, glycine, lysine, histidine, and arginine rose significantly in response to fasting (P less than .05 to .01) due to increased splanchnic fractional extraction. Although the splanchnic fractional extraction of alanine was augmented by 40% (P less than .001), net splanchnic uptake was not influenced by fasting. Total net splanchnic uptake of amino acids increased by 68%, from 231 +/- 44 mumol/min in the postabsorptive state to 388 +/- 63 mumol/min (mean +/- SEM) (P less than .05) in the 60-hour fasted state. However, only one half of this rise was accounted for by gluconeogenic amino acids.

Haemodynamic effects of a long-acting somatostatin analogue in patients with liver cirrhosis

The influence of SMS 201-995 (octreotide, Sandostatin), a long-acting somatostatin analogue, on splanchnic haemodynamics was studied in 15 patients with liver cirrhosis and in 5 healthy individuals before, during, and after 60 min of intravenous SMS infusion (25 and 50 micrograms/h, respectively). No adverse effects of the SMS infusion were seen. In the basal state the estimated hepatic blood flow was 1.04 +/- 0.08 l/min (mean +/- SE) in the patients and 1.62 +/- 0.09 l/min (P less than 0.001) in the controls. At 15 min after the beginning of the infusion the blood flow had already decreased by 15-30% (P less than 0.05-0.01). The reduction was more marked in controls than in patients, and it persisted in both groups during and for 60 min after the infusion. Wedged hepatic venous pressure, measured in the patients, was 20 +/- 2 mmHg in the basal state and 18 +/- 1 mmHg during the infusion (P less than 0.05), and it remained at this level for 60 min after the infusion. Free hepatic venous pressure was unchanged throughout the study. Splanchnic oxygen uptake was similar in the two groups in the basal state and remained unaltered during and after SMS infusion. Both heart rate and arterial systolic and diastolic blood pressure remained unchanged during SMS administration. In summary, SMS infusion results in a fall in hepatic blood flow and a slight but significant decrease in wedged hepatic venous pressure, whereas no effect was noted on the systemic circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain cortical amino acids measured by intracerebral dialysis in portacaval shunted rats

The extracellular amino acid content was measured in the parietal cortex in portacaval and sham operated rats, using the brain dialysis technique. The amino acid content of the perfusate was determined for 10 min before and during stimulation with potassium chloride. Basal levels of aspartate, glutamine, glycine, methionie, valine, phenylalanine and leucine were 2-to 6-fold higher in the PC-shunted as compared to the sham operated rats. For glutamate, taurine, and GABA no differences were observed between the two groups. After KCl stimulation the release of glutamate and GABA increased significantly in both groups. For GABA this rise was approximately twice as high in the PC-shunted rats (+300%, P less than 0.01) as in the sham operated rats (+150%, P less than 0.01 as compared to basal). In the sham operated, but not in the PC-shunted rats, methionine and valine levels rose significantly (+200%, P less than 0.05) and glutamine release decreased (-50%, P less than 0.05). These findings suggest that the brain metabolism of amino acids is altered after a portacaval shunt. This could in turn alter the neurotransmission and partly explain the low spontaneous motor activity seen in these animals.

Splanchnic and leg exchange of free fatty acids in patients with liver cirrhosis

Splanchnic and leg exchange of free fatty acids (FFA), glycerol and ketone bodies, as well as FFA turnover, were determined in the post-absorptive state in 8 patients with liver cirrhosis and in 6 healthy control subjects. The catheter technique was used together with tracer ([14C]oleate) infusion. The arterial concentrations of FFA, glycerol and ketone bodies were 2-6-fold higher in the patients than in the controls. The FFA turnover was 230% greater in the patients, while the fractional turnover was similar in the two groups. In the splanchnic region as well as in the leg, both FFA uptake and release were increased 2-4-fold in the patients. The fractional uptake of FFA was reduced in both areas, indicating that the augmented uptake was due to the high circulating FFA levels alone. The splanchnic production of ketone bodies was four times higher in the patients than in the controls (295 +/- 30 vs 87 +/- 11 mumol/min). The fraction of FFA converted to ketone bodies was greater (42 +/- 6 vs 20 +/- 5%, P less than 0.05), indicating that the accelerated ketone body production was a combined effect of raised FFA uptake and altered intrahepatic metabolism of FFA. The splanchnic production of glucose was reduced by approximately 50% in the patients, while the uptake of glycerol was augmented. The leg uptake of 3-hydroxybutyrate was increased 300% and the release of glycerol was 200% greater in the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of a long-acting somatostatin analogue on splanchnic haemodynamics and metabolism in healthy subjects and patients with liver cirrhosis

The influence of a long-acting somatostatin octapeptide analogue (SMS 201-995) on splanchnic circulation and metabolism has been studied in healthy subjects and in patients with liver cirrhosis. In healthy subjects doses of 5, 10, 50, or 100 micrograms SMS and in the cirrhotic patients 25 micrograms SMS were infused intravenously during 1 h. Measurements were obtained before, during, and for 1 h after SMS infusion. SMS infusion in healthy subjects resulted in a 25-35% reduction in hepatic blood flow. This effect was largely independent of the dose used. Splanchnic oxygen uptake was unchanged before and during SMS infusion. Insulin and glucagon levels fell markedly in response to SMS administration, and the blood concentration and splanchnic output of glucose decreased transiently. Patients with liver cirrhosis responded to SMS infusion similarly to the healthy subjects. Hepatic blood flow decreased by 25-35% and remained suppressed for at least 1 h after infusion. Wedge hepatic venous pressure was 18 +/- 2 mm Hg in the basal state and decreased progressively during and after SMS infusion (60 min after infusion, 15 +/- 2 mm Hg; P less than 0.01). The marked hyperinsulinaemia and hyperglucagonaemia seen in the basal state decreased significantly during SMS administration. As in the case of the controls, blood concentration and splanchnic output of glucose fell transiently during and after SMS infusion. It is concluded that SMS exerts a marked and prolonged suppressive effect on hepatic blood flow in both healthy subjects and patients with liver cirrhosis.(ABSTRACT TRUNCATED AT 250 WORDS)