Branched-chain amino acids vs lactulose in the treatment of hepatic coma: a controlled study

Amino acid imbalance following portal diversion in the rat. The relevance of nutrition and of hepatic function

End-to-end portacaval transposition has previously been shown to produce less hepatocellular dysfunction than end-to-side portacaval shunt in the rat. Liver weight is also significantly reduced after portacaval shunt compared to portacaval transposition and these differences are not abolished by pair-feeding. Histological evidence of CNS damage is also reduced in transposed rats compared to shunted animals. This study examines the amino acid and hormone changes in these models. The characteristic amino acid changes of chronic liver disease (decreased branched-chain and elevated aromatic amino acids) are reproduced in portacaval shunt rats, but not in portacaval transposition. The differences between these groups in the branched-chain amino acids, but not those in the aromatic amino acids, are reduced by pair-feeding. Insulin and glucagon are elevated to a similar extent in both groups. These findings add further support to a role for peripheral amino acid imbalance in the pathogenesis of portal-systemic encephalopathy. Normal liver function, maintained by replacement of portal inflow with systemic blood, appears to minimize both CNS damage and amino acid changes.

High lipid parenteral nutrition improves portasystemic encephalopathy

We have conducted a randomized double crossover study over 4 days in six parenterally fed patients with portasystemic encephalopathy (PSE) in which the nonprotein energy source of otherwise identical feeds was alternately all glucose or predominantly fat. Concentrations of plasma branched chain amino acids (BCAA), plasma insulin, and blood glucose were measured after an initial fast and subsequently after each of the four 24-hr periods of isonitrogenous feeding. The grade of PSE was assessed clinically and by the number connection test, BCAA concentrations were significantly lower during the glucose infusion than during fasting or the lipid infusion. PSE was significantly less with the lipid than with the glucose infusion. Trials testing the effect of infused BCAA must take account of the opposing effect on BCAA concentrations of simultaneous glucose infusion. A high lipid feed may have advantages in the short-term treatment of PSE.

Metabolic effects of enteral formula feeding in alcoholic hepatitis

The etiology of malnutrition and the metabolic effect of aggressive nutritional support by enteral feeding were evaluated in patients with moderately severe alcoholic hepatitis. Among 21 patients presenting with jaundice, ascites, coagulopathy and low grade encephalopathy, the mean digestibilities (intake - fecal excretion/intake x 100) of total energy and fat were subnormal at 74.6 +/- 2.9 and 64.5 +/- 4.4%, respectively, and nitrogen balance was negative in half the patients with a mean value of +0.74 gm per day +/- 1.2. Based on initial ad libitum intake of hospital diet, patients were grouped as six patients with adequate caloric intake who underwent a repeated 3-day balance study to assess the effect of hospitalization (Group I) and eight anorectic patients who underwent a repeat balance study during constant nasoduodenal infusion of the liquid formula Isocal-HCN in an amount sufficient to provide 35 kcal per kg ideal body weight (Group II). During the initial phase of hospital tray diet, the mean digestibilities of energy, fat, protein and carbohydrate, and the mean nitrogen balance were similar in each group. The digestibilities of each diet constituent and nitrogen balance were similar in both phases of hospital tray diet in patients in Group I. On the other hand, the infusion of Isocal-HCN to patients in Group II resulted in significant increases over their baseline values in intakes of energy and protein and in digestibilities of energy, fat and protein, and in a 5-fold increase in nitrogen balance. Provision of essential nutrients by enteric infusion had no effect on fluid balance or degree of encephalopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Enteral and parenteral branched chain amino acid-supplemented nutritional support in patients with encephalopathy due to alcoholic liver disease

The effects of branched chain amino acid (BCAA)-enriched diets (fed for 7 days) on encephalopathy, plasma amino acid concentrations, aromatic amino acid turnover, and protein synthesis rates were determined in eight patients with alcoholic liver failure. Four patients were given the diet intravenously (iv group) (total amino acids, 60-80 g/day, BCAA content 51%, energy 2000 kcal/day) and four patients (NG group) were given a semi-elemental formulation via constant nasogastric (NG) infusion (amino acids 58 g, BCAA 43%, oligopeptides 19.5 g, energy 2000 kcal/day). The enteral diet was given at one-half strength for the first 3 days. A 10-hr constant infusion of [U-14C]phenylalanine tracer was used in four patients to measure aromatic amino acid (AA) turnover and rates of incorporation into various body proteins. Seven of the eight patients made a good clinical recovery, with reversal of encephalopathy within 3 days of dietary intervention. One became septicemic and deteriorated. While plasma bilirubin concentrations dropped, liver enzymes remained elevated. Mean nitrogen balance was negative at the beginning and positive at the end of the study, in both groups. Initial amino acid profiles demonstrated low plasma BCAA content and BCAA:AA ratios. Significant improvements occurred in the iv group by day 2 and in both groups by day 7. Isotope studies showed that, whereas aromatic amino acid oxidation remained unchanged, greater quantities were incorporated in whole body protein, albumin, transferrin, fibrinogen, and immunoglobulins.

A key to the literature of total parenteral nutrition: update 1987

This comprehensive bibliography is intended to enhance the education of the practitioner, student, and academician in the area of parenteral nutrition. This bibliography is not all-inclusive but serves as an update from the original published in 1983. Of particular note in this work is the addition of topics that reflect a growing interest in medical specialties with regard to patient nutritional status and support.

[Effects of discontinuous intravenous infusion of ramified amino acids on blood insulin, blood glucagon and protein metabolism in cirrhotic patients after 10 days. Results of a controlled comparative study with sorbitol]

In order to evaluate the effects of ramified amino acids on insulinaemia, glucagonaemia and protein metabolism, a 3-hour infusion of ramified amino acids (24 g in a 750 ml solution) was given daily during 10 days to 10 cirrhotic patients without hepatic encephalopathy (group I). Changes between the first and tenth day in plasma concentrations of plasma insulin, glucagon, ammonium, ramified and aromatic amino acids and 3 proteins (albumin, prealbumin and transferrin) markers of protein malnutrition were measured comparatively with 10 other cirrhotic patients who received daily a 750 ml infusion of 5 p. 100 sorbitol (group II). The patients, who had been randomized to group I or II, had à 2,200 calorie/day diet representing a 6 to 12 g nitrogen intake. The ramified amino acid infusions were well tolerated. They produced a significant (p less than 0.001) increase in glucagonaemia without significant change in insulinaemia, and a non-significant decrease of the plasma insulin/glucagon molar ratio. The arterial blood ammonium level was significantly (p less than 0.05) lowered in group I as compared to group II. The plasma ramified/aromatic amino acid molar ratio significantly (p less than 0.01) increased in group I but did not reach normal values; this increase was not significant when compared to group II. Finally, plasma concentrations of the 3 proteins indicating protein malnutrition remained low in both groups. These results suggest that daily intravenous administration of ramified amino acids for 10 days, to supplement a conventional diet failed to correct the protein hypercatabolism associated with cirrhosis; induced, however, a decrease in arterial blood ammonium levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of branched-chain amino acids and branched-chain keto acids on protein synthesis in isolated hepatocytes

We investigated the effects of the branched-chain amino acids--valine, leucine and isoleucine--or their keto analogs, the branched-chain keto acids--alpha-ketoisovaleric acid, alpha-ketoisocaproic acid and alpha-keto-beta-methylvaleric acid--on protein synthesis and secretion by monolayers of rabbit hepatocytes incubated with [35S] methionine in pulse-chase and steady-state experiments. The branched-chain amino acids (2.0 mM or 1.0 mM), in the presence or absence of insulin (2 X 10(-4) IU per dish) and in both types of experiments, reduced the trichloroacetic acid-precipitable 35S-protein secreted into the medium. The branched-chain keto acids (2.0 mM or 1.0 mM) had a stimulatory effect on secreted trichloroacetic acid-precipitable 35S-protein which was observed only by the pulse-chase technique in the presence of insulin. Immunoaffinity chromatography of medium demonstrated a slight inhibition by branched-chain amino acids and a slight stimulation by branched-chain keto acids on secretion of 35S-albumin and no effect of either treatment on secretion of 35S-fibrinogen. ELISA analysis of total (i.e., 35S-labeled and unlabeled) secreted albumin revealed an inhibitory effect of the branched-chain amino acids in both pulse-chase and steady-state experiments, and a small stimulatory effect, in steady-state experiments, of the branched-chain keto acids; both effects were insulin-dependent. Total secreted fibrinogen, under steady-state conditions, was increased by the branched-chain keto acids in the presence of insulin, while transferrin production was unaffected by any treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Nutritional considerations for the burned patient

The metabolic response to injury is one of marked catabolic hormonal predominance resulting in hypermetabolism and protein wasting. Energy expenditure increases with increasing severity of injury, but reaches a maximum of twice resting energy expenditure when 50 per cent TBSA is burned. We agree with the nutritional recommendations of the group at the Boston Shriner's Burn Institute and the Massachusetts General Hospital. These include providing calories at twice the resting energy expenditure, as predicted by the Harris-Benedict equations, for patients with greater than 30 per cent BSAB; protein is provided at 2.5 gm per kg per day based on ideal body weight. It is important to recognize that these are optimal goals, but their attainment must be governed by safety considerations for the patient. It is probably safe to supplement intake with a multivitamin and vitamin C, as well as zinc, but our understanding of micronutrient therapy for stressed patients is rudimentary.

Amino acids and hepatic encephalopathy

The consideration of HE and its etiology has undergone a radical turn within the past decade. At present HE is seen in the context of severe metabolic derangements, which failure of the liver, the central biochemical powerhouse of the body, must bring with it. The increased awarenesses on the biochemical mechanisms involved in the pathogenesis of HE have found, step by step, their own place in a complex but consequential mosaic of events, in which amino acid and HE are tightly linked. Clinical and experimental studies are needed to further improve the knowledge in this field, nontheless a certain number of corner-stones can be identified: A profound alteration of the central nervous system neurotransmission is responsible for most, if not all, of the symptoms characterizing HE. The plasma amino acid imbalance observed in cirrhotic patients represents a 'condicio sine qua non' HE may develop. A functional impairment of the amino acid transport systems at the level of the blood-brain barrier seems to play a crucial role in causing deleterious modifications of the synaptic neurotransmission in the central nervous system. The reduction of the brain entry of the "toxic" aromatic amino acids usually obtained by parenteral administration of especially tailored amino acid mixtures is most frequently followed by awakening from HE. In conclusion, most of the results obtained have demonstrated that HE represents a research field in which progresses in the knowledge of some of the pathogenic mechanisms have brought the investigators to new therapeutic approaches which have clearly improved the prognosis of patients suffering from this severe neuropsychiatric syndrome.

Metabolic effects of branched chain amino acids in patients with severe pancreatitis

Twenty-four patients with acute severe pancreatitis were randomised to receive total parenteral nutrition for 7 days with one of two isocaloric (35 kcal/kg/day) and isonitrogenous (0.16 g/kg/day) programmes containing either a low (15.5% w/w (control group)) or a high (57%) content of branched chain amino acids (BCAA (BCAA group)). During treatment, the nitrogen balance was similar in both groups. The concentrations of serum protein, albumin, prealbumin and retinol-binding protein did not differ between the groups. The plasma concentrations of BCAA measured 2 h after discontinuation of amino acid infusions rose in the BCAA group. In urine, only the concentrations of valine increased as compared with those of control patients. Serum glucose levels were higher in the BCAA group than in the control group, although the BCAA group received slightly more insulin than the control group in order to keep the blood glucose concentration below 10 mmol/l. The results suggest that BCAA-enriched solutions may stimulate gluconeogenesis without affecting catabolism.

Nutritional support: how much for how much?

Although malnutrition is associated with poor clinical outcome, it cannot be inferred that better nutrition will improve clinical outcome. Efficacy of a proposed regimen is best established by prospective, randomised, controlled trials. Cost effectiveness is only an issue if efficacy exists. Patients with long term temporary, or permanent, inadequate bowel syndrome are candidates for parenteral nutrition. Most of the prospective, randomised, controlled trials testing the value of nutritional support in other diseases, however, have failed to show that this treatment has a beneficial clinical effect. Areas where these trials have shown a possible clinical benefit include the perioperative care of patients with upper gastrointestinal cancer, elemental diet treatment of Crohn's disease, and branched chain amino acid infusions in hepatic encephalopathy. Even in these instances, it is not clear that such treatment will prove to be cost effective (compared with other currently available treatments).

Use of branched chain amino acids for treating hepatic encephalopathy: clinical experiences

The efficacy of branched chain amino acids in two consecutive clinical studies in patients with severe hepatic encephalopathy was tested. In the preliminary uncontrolled study 19 patients with grade 3-4 hepatic encephalopathy were given an intravenous solution containing leucine 11 g/l, isoleucine 9 g/l, and valine 8.4 g/l in 20% dextrose. A complete recovery of mental state was obtained in all patients in a mean time of 20.5 hours. In a subsequent controlled study 40 patients with grade 3-4 hepatic encephalopathy were randomly assigned to receive intravenous branched chain amino acid in 20% dextrose (group A) or oral lactulose (group B). Twelve patients (70.6%) in group A and eight (47%) in group B regained consciousness in a mean time of 27.6 and 31.5 hours, respectively. The difference in the recovery rate between the two groups, although evident, was not significant. Intravenous branched chain amino acids are thus at least as effective as lactulose in reversing hepatic coma. These data argue strongly in favour of a therapeutic effect of branched chain amino acids in the treatment of hepatic encephalopathy in patients with chronic liver failure.

Failure of glucose and branched-chain amino acids to normalize brain glucose use in portacaval shunted rats

Several abnormalities in brain and plasma amino acid concentrations caused by portacaval shunting in rats return toward normal after 4 days of intravenous infusion with either glucose or glucose with branched-chain amino acids. To assess the effect of such treatment on brain energy metabolism, regional brain glucose use was measured using [14C]glucose and autoradiography, 5 weeks after portacaval shunting. In one experiment intravenous glucose or glucose with branched-chain amino acids was given for 4 days. In a separate experiment the treatment was given orally for 2 weeks, and in addition to glucose use, brain monoamines and amino acids were measured. No other food was provided; the rats had free access to water. Normally fed shunted rats and sham-operated rats served as controls. Both types of oral treatment lowered the high concentrations of tyrosine, phenylalanine, and glutamine in plasma and brain. Glucose without amino acids normalized brain tryptophan. Levels of brain norepinephrine, 5-hydroxytryptamine (serotonin), and 5-hydroxyindoleacetic acid were significantly raised after shunting. Treatment had no effect on norepinephrine but the glucose diet brought the indoles into the normal range. In contrast, neither intravenous nor oral treatment affected brain glucose use, which remained depressed by 25-30% in all brain areas examined.

Branched-chain amino acid interactions in skeletal muscle: isoleucine and L-alloisoleucine

Parenteral administration of a mixture of branched-chain amino acid (BCAA) solutions is known to alter plasma levels of the BCAA (ILE, LEU, VAL), their corresponding alpha-ketoacids (KMV, KIC, KIV) and L-alloisoleucine (ALLO), a stereoisomer of ILE. Although variously formulated mixtures of BCAA are administered, the metabolic implications of individual BCAA interactions have been only partially elucidated. Using the incubated, isolated, and intact rat epitrochlearis muscle, we measured the effect of graded increases (0.05, 0.10, 0.5, and 1.0 mM) in media concentrations of a single BCAA or ALLO on (1) the rate of decarboxylation of the other BCAA, and (2) the release of branched chain ketoacids from muscle. A graded increase of media ILE concentration to 1.0 mM changed the decarboxylation of LEU by -28%, and the release of KIC by +23%, but VAL decarboxylation increased by +25%, and the release of KIV declined by -56%. A graded increase of media LEU to 1.0 mM increased ILE decarboxylation by +146%, and its corresponding ketoacid (KMV) by +61%. However, VAL decarboxylation changed by only +25% and KIV release declined by -65%. A graded increase in media VAL to 1.0 mM accelerated ILE decarboxylation by +37%, but KMV release was unchanged. Similarly, LEU decarboxylation fell by -26%, and the release of KIC by only +6%. ALLO 0.025 mM increased ILE release by +55% but had an inconsistent effect on ILE decarboxylation and did not alter protein synthesis or degradation (estimated by phenylalanine incorporation and tyrosine release, respectively). Increasing ILE did not affect ALLO release.(ABSTRACT TRUNCATED AT 250 WORDS)

Ammonia toxicity: comparative protective effect of various arginine and ornithine derivatives, aspartate, benzoate, and carbamyl glutamate

Ornithine and arginine compounds were highly effective in preventing an increase in blood ammonia and in preventing or minimizing encephalopathy after acute subcoma, coma-inducing, or lethal doses of NH4+. Similar protection was seen after subacute loading with glycine. Ornithine ketoacid derivatives were no more effective than ornithine alone or ornithine glutamate. Ornithine appeared to be a little more effective than arginine, but the differences were slight. Aspartate and glutamate alone were ineffective. Carbamyl glutamate was much less effective than either ornithine glutamate or arginine glutamate. Orotic acid excretion was markedly increased in the presence of excess NH4+. This increment was eliminated with ornithine or arginine, although the reduction with arginine was unpredictably erratic. Aspartate increased the orotic acid excretion and the amount of urea formed. Sodium benzoate was borderline in its effect on the blood ammonia and on orotic acid excretion.

[Branched-chain amino acids in the treatment of latent porto-systemic encephalopathy. A placebo-controlled double-blind cross-over study]

In a doubleblind cross-over placebo-controlled trial the efficiency of oral treatment with branched chain amino acids was investigated in 22 inpatients with liver cirrhosis. In all patients evidence of latent (subclinical) portalsystemic encephalopathy was obtained by using an extensive psychometric test programme. Patients received a defined diet of 35 cal/kg/day containing 1 g of protein. In addition, branched chain amino acids or casein in a dosage of 0.25 g/kg/day was administered in a cross-over fashion, each for 1 week. Semiquantitative nitrogen balance increased during both treatments, with a tendency towards a larger increase during branched chain amino acid treatment. At the same time ammonia concentration tended to decrease during branched chain amino acid treatment. Taking into account the cross-over design, significant improvements attributable to branched chain amino acid treatment could be demonstrated in psychomotor functions (line tracing, tapping, steadiness, auditory reaction time), attention (digit table), and practical intelligence (digit symbol, number connection test).

Branched chain amino acid-enriched solutions in the septic patient. A randomized, prospective trial

A prospective, randomized trial was undertaken to compare the nutritional efficacy in surgical stress of a standard amino acid solution and two branched chain-enriched amino acid solutions: one enriched primarily with valine, the other with leucine. The study comprised 37 patients in the surgical intensive care unit who received isocaloric, isonitrogenous parenteral nutrition started within 24 hours of the onset of major operation, injury, or sepsis. Nitrogen retention was marginally but statistically significantly better on days 5, 7, and 10 in both groups of patients receiving the branched chain-enriched solutions, but differences in cumulative nitrogen balance were not statistically significant. Amino acid composition appeared to be important in that the group receiving the leucine-enriched solution appeared to maintain hepatic protein synthesis better (as manifest by higher short-turnover plasma protein concentrations) and required less exogenous insulin to maintain euglycemia. Improved outcome was not seen in the groups receiving the branched chain-enriched solutions.

Intravenous feeding--a review of aspects of current practice

This review summarises the present state of knowledge of energy and nitrogen requirements of hospital patients requiring intravenous feeding. It also addresses electrolyte, inorganic element and vitamin intakes, and examines possible differences in requirements in some special circumstances. It is concluded that most of the patients could be fed using one of a small number of standard regimens.

Enriched branched-chain amino acid formula versus a casein-based supplement in the treatment of cirrhosis

An orally administered branched-chain amino acid (BCAA) rich supplement (T), Travasorb-Hepatic was compared to a casein based supplement (E), Ensure, in a randomized double-blind cross-over study in eight malnourished, stable cirrhotics unable to achieve a daily dietary protein intake of 1.0 g/kg. Doses of antiportal systemic encephalopathy drugs remained constant and a baseline 1000 kcal, 40 g dietary protein intake was encouraged. To this diet, supplemental protein was added in daily 20-g increments to a maximum of 60 g supplemental protein. Mental status, asterixis, and number connection tests were assessed daily and an antiportal systemic encephalopathy index calculated. There was no significant difference in the mean intake of dietary protein (T, 33.7 +/- 4.0 g; E, 26.7 +/- 10.8 g), supplemental protein (T, 43.1 +/- 8.3 g; E, 47.9 +/- 7.1 g), or N2 balance (T, 4.2 +/- 3.7 g; E, 3.4 +/- 4.4) between treatment trials. The antiportal systemic encephalopathy index improved on E, with no significant change in the BCAA:aromatic acid molar ratio. This ratio improved on T (1.02 +/- 2.0 to 2.7 +/- 1.1), but was not accompanied by improvement in the antiportal systemic encephalopathy index. The improved protein tolerance in both groups was not further increased by a highly enriched BCAA formula compared to one with a moderate BCAA content from a natural dietary protein source. Thus, both conventional casein-based supplements and enriched BCAA formulas are well tolerated and can be safely and effectively used as an integral part of diet therapy.

Brain monoamine metabolism and behavior in portacaval-shunted rats

Animals with a portacaval shunt exhibit several biochemical abnormalities in plasma and brain similar to patients with portal-systemic encephalopathy, i.e., hyperammonemia, amino acid imbalance, and neurotransmitter disturbances. We investigated behavior and brain monoamine metabolism in operated, sham-operated, and nonoperated rats 1 day and 2, 4, and 6 weeks after operation. In order to quantitate the turnover in the brain indoleamine and catecholamine systems, 5-hydroxytryptophan (5-HTP) and dihydroxyphenylalanine were measured after decarboxylase inhibition with NSD 1015. The brains were dissected into five regions. All rats with the shunt had high plasma ammonia concentrations. Behavioral tests revealed a reduction in spontaneous locomotion 2, 4, and 6 weeks after portacaval shunt and reduced exploratory behavior compared with control rats. These changes coincided with profound alterations of the indoleaminergic system. As early as 1 day after surgery, rats with the shunt showed a marked increase in the accumulation of 5-HTP in all brain regions, indicating an enhanced tryptophan hydroxylase activity. The changes in indoleamine synthesis were most profound in the cortex and the midbrain. Only minor alterations of the catecholaminergic system could be detected. The alterations in behavior and indoleamine neurotransmitter metabolism may be pathophysiologically interrelated and may serve as the basis for experimental studies of portal-systemic encephalopathy.

Treatment of acute hepatic encephalopathy in cirrhotics with a branched-chain amino acids enriched versus a conventional amino acids mixture. A controlled study of 70 patients

Acute hepatic encephalopathy in 70 cirrhotic patients was monitored during parenteral administration of amino acids between January 1979 and January 1984. The diagnosis of cirrhosis was confirmed by needle biopsy, and HE by conventional clinical and EEG parameters. The infusion of AA solutions was initiated 48 h after admission and during a 5-day period: 34 patients received a control aminoacid solution, a commercially available AA mixture (Azonutril), and 36 patients a modified solution enriched in BAA prepared from crystallized AA dissolved in distilled water. The calorie intake for both groups was 1600 calories per day from glucose and lipid emulsion. No significant difference was noted based on clinical evolution, even though the plasma AAA/BAA ratio was corrected using the modified AA solution. Of the 34 patients in Group 1: 10 improved, 14 were unchanged, 10 deteriorated and 7 died. Of the 36 patients in Group 2: 12 improved, 14 were unchanged, 10 deteriorated and 7 died. EEG tracing evolved in parallel fashion. The authors conclude that modified AA solutions are ineffective in the treatment of acute hepatic encephalopathy in cirrhotic patients.

Standard or branched-chain amino acid infusions as short-term nutritional support in liver cirrhosis?

The metabolic effects of selected and branched-chain amino acid (BCAA)-enriched parenteral solutions were studied in liver cirrhosis. After 3 days of an oral protein-free diet with balanced amino acid (AA) infusion, 36 cirrhotic patients without encephalopathy were randomly divided into four groups. Groups A and B were infused for 5 days with BCAA (valine, leucine, isoleucine) at doses of 0.5 and 1.0 g/kg/day, respectively, as the only nitrogen source. Group C received 0.8 g/kg of essential and nonessential AA solution with a prevalence of BCAA; the last group (D) continued the basic standard diet, as control. Routine chemistry, urinary nitrogen losses, nitrogen balance, and the whole plasma AA pattern were detected before and after the treatment period. BCAA alone led to an impressive and significant improvement in the basic AA pattern in both the A and B groups. The same results were obtained in group C for plasma AA. In particular, the ratio of BCAA to aromatic amino acids in groups A, B, and C was significantly increased (p less than 0.01, less than 0.02, less than 0.02, respectively). In group D the AA pattern and the BCAA/aromatic amino acid ratio remained unchanged. The negative nitrogen balance of the base state remained unchanged after 0.5 g of BCAA (A); it improved significantly and became positive during and after the infusions of a double dose of BCAA (B), as it did in the case of selective solutions (C), although to a lesser extent; the negative nitrogen balance of the control group showed only a slight improvement.(ABSTRACT TRUNCATED AT 250 WORDS)

Disease-specific amino acid infusion (F080) in hepatic encephalopathy: a prospective, randomized, double-blind, controlled trial

Seventy-five patients with acute hepatic decompensation superimposed on chronic alcoholic cirrhosis were prospectively randomized for a blinded trial of the treatment of hepatic encephalopathy. The control group received 4 g of enteral neomycin daily along with 25% dextrose by a central venous catheter. The experimental group received a placebo resembling neomycin and isocaloric dextrose plus a modified amino acid mixture enriched with branched-chain amino acids to 36% and deficient in aromatic amino acids and methionine. Thirty patients in the F080 group and 29 in the control group completed the trial. The group receiving the modified amino acid mixture demonstrated a statistically significant improvement in encephalopathy as compared to the neomycin group, while maintaining nitrogen equilibrium. Survival and discharge from the hospital were statistically greater in the group treated with the modified amino acid solution and hypertonic dextrose. Treatment of hepatic encephalopathy in the presence of hepatic decompensation with an amino acid solution formulated for its treatment seems to produce faster, more complete recovery with improved capacity for nutritional support.

Branched chain amino acids in the treatment of latent portosystemic encephalopathy. A double-blind placebo-controlled crossover study

Branched chain amino acids have been recommended for the treatment of portosystemic encephalopathy based on the false neurotransmitter hypothesis. This hypothesis implies that by correction of the deranged amino acid pattern in the blood of cirrhotics, false neurotransmission and then portosystemic encephalopathy is improved. We conducted a double-blind crossover placebo-controlled trial in 22 inpatients with liver cirrhosis and obtained evidence of latent (subclinical) portosystemic encephalopathy using an extensive psychometric test program. Patients received a defined diet of 35 cal/kg X day containing 1 g of protein. In addition, branched chain amino acids or casein in a dosage of 0.25 g/kg X day was administered in a crossover fashion, each for 1 wk. Semiquantitative nitrogen balance increased during both treatments, with a tendency of a larger increase during branched chain amino acid treatment. At the same time ammonia concentration tended to decrease during branched chain amino acid treatment. Taking into account the crossover design, significant improvements attributable to branched chain amino acid treatment could be demonstrated in psychomotor functions (line tracing, tapping, steadiness, auditory reaction time), attention (digit table), and practical intelligence (digit symbol, number connection test).

Branched chain amino acid therapy in liver disease

Patients with hepatic cirrhosis often are malnourished and wasted. If portal-systemic encephalopathy (PSE) develops, restriction of dietary protein in an attempt to treat encephalopathy may further promote negative nitrogen balance. There is considerable interest in providing nutritional supplements to patients with cirrhosis and PSE which would lead to improvement in nitrogen balance while improving or at least not worsening PSE. Amino acid supplements designed to correct the abnormal amino acid pattern characteristically found in patients with cirrhosis and PSE are under investigation as potential therapeutic agents. The levels of the branched chain amino acids (BCAAs) are decreased in almost all patients with cirrhosis and PSE. The exact mechanism for the reductions in BCAA concentrations is unknown. Furthermore, aromatic amino acids (AAA) and methionine (MET) concentrations are usually increased in these patients. It has been suggested that BCAAs and neutral amino acids compete for transport across the blood-brain barrier and that a decrease in BCAA concentrations promotes entrance of neutral amino acids into the brain. Aromatic amino acids, MET, and their derivatives may have a role in the production of PSE. These observations have increased interest in the potential therapeutic benefit of administering BCAAs to patients with cirrhosis and PSE in order to decrease the entrance of putative toxins into the brain. Treatment trials using BCAAs alone or in solutions containing other amino acids in patients with cirrhosis and PSE have given conflicting results. In one trial, there appeared to be less PSE induced by a BCAA-enriched solution when compared to equinitrogenous dietary protein. However, other controlled studies have not demonstrated any advantage to the addition of BCAAs as compared to placebo with regards to reducing mortality or improving cerebral function in patients with acute cirrhosis and PSE. Some of the differences in study outcomes may relate to the patient population evaluated; the type, amount, and duration of treatment; and whether other therapy was administered. BCAA supplements may also be useful in minimizing or reversing the catabolic state characteristic of patients with cirrhosis. A reduction of increased urinary 3-methylhistidine excretion by infusions of BCAAs in cirrhotic patients suggests an anticatabolic effect. These potential anticatabolic effects of BCAAs are most interesting and deserve further study.

L-Leucine prevents ammonia-induced changes in glutamate receptors in the brain and in visual evoked potentials in the rabbit

The effect of L-leucine on glutamate receptors in the brain and on visual evoked potentials was studied in hyperammonemic rabbits. Hyperammonemia was induced by the iv infusion of 2.1 mmol NH4Cl/h over 3 hr. Hyperammonemia was followed by a 116% increase in the specific binding of 3H-glutamate to synaptic membranes prepared from the hippocampus. This increase was due to both an increase in the affinity and in the density of the glutamate receptor. The simultaneous infusion of L-leucine (6.7 mmol/hr) completely prevented the ammonia-induced increase in the specific glutamate binding, whereas L-valine and D-leucine had no effect. Hyperammonemia was also associated with typical, reproducible, and reversible changes in visual evoked potentials. The amplitudes of the first negative and the second positive peak decreased, whereas the latencies of these peaks remained unchanged. The simultaneous infusion of L-leucine completely prevented these changes. These findings indicate (1) that L-leucine prevents ammonia-induced changes in the glutamatergic excitatory neurotransmitter system and (2) that pharmacologic doses of L-leucine modulate the effects of hyperammonemia on central neurotransmission as assessed by visual evoked potentials. A causal relationship between the effects of L-leucine on ammonia-induced changes in glutamate receptors and in visual evoked potentials cannot be inferred with confidence. These findings provide a potential alternative explanation for the apparent beneficial effects of infusions of branched-chain amino acids on hepatic encephalography in patients with chronic liver disease.

Amino acid, ammonia and neurotransmitter concentrations in hepatic encephalopathy: serial analysis in plasma and cerebrospinal fluid during treatment with an adapted amino acid solution

We evaluated changes of advanced liver disease and hepatic encephalopathy on the concentrations of amino acids (AA) and ammonia in plasma and cerebrospinal fluid (CSF) and of the neurotransmitters norepinephrine, dopamine and 5-hydroxytryptamine (5-HT) as well as the 5-hydroxyindole acetic acid (5-HIAA) in CSF before and at the end of a 3-day period of treatment with infusions enriched with branched chain amino acids (BCAA). The subjects studied were 13 patients with alcoholic cirrhosis and hepatic encephalopathy stages 1-3 (n = 8) and stage 4 (n = 5). The patients in coma stages 1-3 recovered during the treatment (survivors), those in coma stage 4 died before the study period was finished (non-survivors). The data emerging from this study show: Alterations of AA concentrations are much more pronounced in the CSF than in the plasma. In the case of tryptophan the alterations in plasma and CSF were inverse. Before the treatment the CSF-plasma ratios of the concentrations of BCAA and aromatic amino acids (AAA) are increased reflecting an activated transport of both the BCAA and AAA through the blood-brain barrier. High dose BCAA nearly normalized CSF concentrations and CSF-plasma ratios of AAA assuming that the treatment brought about an effective competition of cerebral uptake between BCAA and AAA. The CSF concentrations of ammonia and glutamine decreased significantly during treatment while the plasma concentrations changed only moderately. As to the neurotransmitters, only the concentrations of 5-HT and its metabolite 5-HIAA correlated with the clinical picture and with the concentration of their precursor AA.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of dietary protein with an oral, branched chain-enriched amino acid supplement in chronic portal-systemic encephalopathy: a randomized controlled trial

A randomized study was conducted in 37 hospitalized patients at six cooperating hospitals in which protein-intolerant cirrhotic patients were fed increasing amounts of either dietary protein or a branched-chain enriched amino acid solution (BCAA) until they attained an intake of 80 gm protein per day or equivalent or until they developed stage 2 encephalopathy. All patients initially received 20 gm of dietary protein for 1 week, after which 20 gm of protein or BCAA were added weekly. Nitrogen balance improved from negative to positive in all patients in whom it was measured and increased equally in both groups. Seven of the 20 patients in the protein group and 1 of 17 in the BCAA group developed encephalopathy of stage 2 or greater (p less than 0.05). Changes in each component of the portal-systemic encephalopathy syndrome were compared, and differences were statistically significant for mental status grade (p less than 0.01), asterixis (p less than 0.05), Portal-systemic encephalopathy index (p less than 0.01), but insignificant for Number Connection Test, EEG or ammonia. Plasma amino acid profiles showed an increase in BCAA in the study group. Thus, oral BCAA supplements appear to induce positive nitrogen balance to approximately the same degree as an equivalent amount of dietary protein without inducing encephalopathy as frequently.

Is intravenous administration of branched chain amino acids effective in the treatment of hepatic encephalopathy? A multicenter study

The influence of intravenous infusion of branched-chain amino acids (BCAAs) on brain function in patients with liver cirrhosis and acute hepatic encephalopathy was examined using a double-blind, randomized study design. Five medical centers in France and Sweden participated, and 50 patients were studied. The patients received either BCAAs (40 gm per day) in 5% glucose or 5% glucose alone (placebo) for 5 days or until "wake up". Nutritional support was provided with equal proportions of carbohydrate and fat. During BCAA administration, plasma concentrations of aromatic amino acids and methionine fell (20 to 40%, p less than 0.05 to 0.01), and the ratio of BCAAs to aromatic amino acid concentrations increased significantly. Clinical improvement was seen in 14 of 25 BCAA-treated patients and in 12 of 25 patients receiving placebo (N.S.). EEG responses were similar in the two groups during treatment. In the BCAA group, 10 of 25 patients died in the course of the study, compared to 5 of 25 in the placebo group (N.S.); six patients died from encephalopathy in the BCAA group as compared to three among placebo-treated patients. It is concluded that BCAA administration, in the dose and composition employed in the present study, reduces the concentrations of aromatic amino acids but neither improves cerebral function nor decreases mortality in patients with hepatic encephalopathy.