Which cava anastomotic techniques are optimal regarding immediate and short-term outcomes after liver transplantation: A systematic review of the literature and expert panel recommendations.

BACKGROUND: It has long been debated whether cava anastomosis should be performed with the piggyback technique or cava replacement, with or without veno-venous bypass (VVB), with or without temporary portocaval shunt (PCS) in the setting of liver transplantation. OBJECTIVES: To identify whether different cava anastomotic techniques and other maneuvers benefit the recipient regarding short-term outcomes and to provide international expert panel recommendations. DATA SOURCES: Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central. METHODS: A systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel (CRD42021240979). RESULTS: Of 3205 records screened, 307 publications underwent full-text assessment for eligibility and 47 were included in qualitative synthesis. Four studies were randomized control trials. Eighteen studies were comparative. The remaining 25 were single-center retrospective noncomparative studies. CONCLUSION: Based on existing data and expert opinion, the panel cannot recommend one cava reconstruction technique over another, rather the surgical approach should be based on surgeon preference and center dependent, with special consideration toward patient circumstances (Quality of evidence: Low | Grade of Recommendation: Strong). The panel recommends against routine use of vevo-venous bypass (Quality of evidence: Very Low | Grade of Recommendation: Strong) and against the routine use of temporary porto-caval shunt (Quality of evidence: Very Low | Grade of Recommendation: Strong).

Reduced Liver Lipid Peroxidation in Subcellular Fractions Is Associated with a Hypometabolic State in Rats with Portacaval Anastomosis.

A surgical connection between portal and inferior cava veins was performed to generate an experimental model of high circulating ammonium and hepatic hypofunctioning. After 13 weeks of portacaval anastomosis (PCA), hyperammonemia and shrinkage in the liver were observed. Low glycemic levels accompanied by elevated levels of serum alanine aminotransferase were recorded. However, the activity of serum aspartate aminotransferase was reduced, without change in circulating urea. Histological and ultrastructural observations revealed ongoing vascularization and alterations in the hepatocyte nucleus (reduced diameter with indentations), fewer mitochondria, and numerous ribosomes in the endoplasmic reticulum. High activity of hepatic caspase-3 suggested apoptosis. PCA promoted a marked reduction in lipid peroxidation determined by TBARs in liver homogenate but specially in the mitochondrial and microsomal fractions. The reduced lipoperoxidative activity was also detected in assays supplemented with Fe2+. Only discreet changes were observed in conjugated dienes. Fluorescent probes showed significant attenuation in mitochondrial membrane potential, reactive oxygen species (ROS), and calcium content. Rats with PCA also showed reduced food intake and decreased energy expenditure through indirect calorimetry by measuring oxygen consumption with an open-flow respirometric system. We conclude that experimental PCA promotes an angiogenic state in the liver to confront the altered blood flow by reducing the prooxidant reactions associated with lower metabolic rate, along with significant reduction of mitochondrial content, but without a clear hepatic dysfunction.

Direct intrahepatic portocaval shunt for treatment of portal thrombosis and Budd-Chiari syndrome.

Budd-Chiari syndrome (BCS) refers to hepatic venous outflow obstruction that in severe cases can lead to acute liver failure prompting consideration of revascularization or transplantation. Here, a 22 year old female with angiographically proven BCS secondary to JAK2/V617F positive Polycythemia vera on therapeutic warfarin presented with acute liver failure (ALF). Imaging revealed a new, near complete thrombotic occlusion of the main portal vein with extension into the superior mesenteric vein. An emergent direct intrahepatic portocaval shunt (DIPS) was created and liver function promptly normalized. She has been maintained on rivaroxaban since that time. Serial assessment over 1 year demonstrated continued shunt patency and improved flow in the mesenteric vasculature on ultrasound as well as normal liver function. DIPS is a viable alternative in the treatment of ALF from BCS when standard recanalization is not feasible. Improved blood flow may also improve portal/mesenteric clot burden. While further investigation is needed, new targeted anticoagulants may be viable as a long term anticoagulation strategy.

Rats with minimal hepatic encephalopathy show reduced cGMP-dependent protein kinase activity in hypothalamus correlating with circadian rhythms alterations.

Patients with liver cirrhosis show disturbances in sleep and in its circadian rhythms which are an early sign of minimal hepatic encephalopathy (MHE). The mechanisms of these disturbances are poorly understood. Rats with porta-caval shunt (PCS), a model of MHE, show sleep disturbances reproducing those of cirrhotic patients. The aims of this work were to characterize the alterations in circadian rhythms in PCS rats and analyze the underlying mechanisms. To reach these aims, we analyzed in control and PCS rats: (a) daily rhythms of spontaneous and rewarding activity and of temperature, (b) timing of the onset of activity following turning-off the light, (c) synchronization to light after a phase advance and (d) the molecular mechanisms contributing to these alterations in circadian rhythms. PCS rats show altered circadian rhythms of spontaneous and rewarding activities (wheel running). PCS rats show more rest bouts during the active phase, more errors in the onset of motor activity and need less time to re-synchronize after a phase advance than control rats. Circadian rhythm of body temperature is also slightly altered in PCS rats. The internal period length (tau) of circadian rhythm of motor activity is longer in PCS rats. We analyzed some mechanisms by which hypothalamus modulate circadian rhythms. PCS rats show increased content of cGMP in hypothalamus while the activity of cGMP-dependent protein kinase was reduced by 41% compared to control rats. Altered cGMP-PKG pathway in hypothalamus would contribute to altered circadian rhythms and synchronization to light.

Hypolocomotion in rats with chronic liver failure is due to increased glutamate and activation of metabotropic glutamate receptors in substantia nigra.

BACKGROUND/AIMS: Patients with hepatic encephalopathy show altered motor function, psychomotor slowing and hypokinesia. The underlying mechanisms remain unclear. This work's aims were: (1) to analyse in rats with chronic liver failure due to portacaval shunt (PCS) the neurochemical alterations in the basal ganglia-thalamus-cortex circuits; (2) to correlate these alterations with those in motor function and (3) to normalize motor activity of PCS rats by pharmacological means. METHODS: Extracellular neurotransmitters levels were analysed by in vivo brain microdialysis. Motor activity was determined by counting crossings in open field. RESULTS: Extracellular glutamate is increased in substantia nigra pars reticulata (SNr) of PCS rats. Blocking metabotropic receptor 1 (mGluR1) in SNr normalizes motor activity in PCS rats. In ventro-medial thalamus of PCS rats GABA is increased and it is normalized by blocking mGluR1 in SNr. Blocking mGluR1 in SNr increases and mGluR1 activation reduces glutamate in motor cortex and motor activity. CONCLUSIONS: Increased extracellular glutamate and activation of mGluR1 in SNr are responsible for reduced motor activity in rats with chronic liver failure. Blocking mGluR1 in SNr normalizes motor activity in PCS rats, suggesting that, under appropriate conditions, similar treatments could be useful to treat the psychomotor slowing and hypokinesia in patients with hepatic encephalopathy.

Soy protein diet prevents hypermethioninemia caused by portacaval shunt in rats.

In hepatic disorders, abnormal plasma amino acid profiles are observed. In this study, we examined whether soy protein isolate (SPI) improved plasma methionine concentration in the model animals. Portacaval shunt (PCS) increased alanine aminotransferase (ALT) activity and methionine concentration in blood of rats fed a 40% casein diet supplemented with 0.6% methionine (casein-M diet). A 40% SPI diet supplemented with 1.28% methionine (SPI-M diet), which contained the same amount of methionine as that in 40% casein-M diet, normalized plasma ALT activity and methionine level in PCS rats. These effects of a SPI diet may be due to its amino acid composition, since an amino acid mixture diet mimicking a 40% SPI-M diet was also effective to hypermethioninemia of PCS rats. To find key enzymes for the beneficial effect of soy protein, we examined effects of a 40% SPI-M or casein-M diet on the activities of three methionine-metabolizing enzymes in liver of PCS rats. A SPI-M diet stimulated only the activity of cystathionine gamma-lyase, compared with a casein-M diet. A SPI diet has a preventive effect on hypermethioninemia, at least in part, by stimulating cystathionine gamma-lyase activity in liver and may be used for nutritional management of liver disorders with hypermethioninemia.

Loss of noradrenaline transporter sites in frontal cortex of rats with acute (ischemic) liver failure.

There is increasing evidence that central noradrenaline (NA) transport mechanisms are implicated in the central nervous system complications of acute liver failure. In order to assess this possibility, binding sites for the high affinity NA transporter ligand [3H]-nisoxetine were measured by quantitative receptor autoradiography in the brains of rats with acute liver failure resulting from hepatic devascularization and in appropriate controls. In vivo microdialysis was used to measure extracellular brain concentrations of NA. Severe encephalopathy resulted in a significant loss of [3H]-nisoxetine sites in frontal cortex and a concomitant increase in extracellular brain concentrations of NA in rats with acute liver failure. A loss of transporter sites was also observed in thalamus of rats with acute liver failure. This loss of NA transporter sites could result from depletion of central NA stores due to a reserpine-like effect of ammonia which is known to accumulate to millimolar concentrations in brain in ischemic liver failure. Impaired NA transport and the consequent increase in synaptic concentrations and increased stimulation of neuronal and astrocytic noradrenergic receptors could be implicated in the pathogenesis of the encephalopathy and brain edema characteristic of acute liver failure.

Hypothalamic histamine, growth rate, plasma prolactin and growth hormone levels in rats with long-term portacaval anastomosis.

OBJECTIVE AND DESIGN: Histamine can modulate feeding behaviour and hormone release; therefore we examined the hypothalamic histamine system, the growth pattern and the serum levels of prolactin and growth hormone in rats with portacaval anastomosis (PCA). MATERIAL: The growth rate of 30 PCA- and 30 sham-operated male Han:Wistar rats was monitored for 6 months. Thirteen sham and 9 PCA rats were used for biochemical studies. METHODS: Histamine was assayed by HPLC, tele-methylhistamine by GC-MS, prolactin and growth hormone by RIA. Student's t-test was used to compare the groups. RESULTS: Six months after surgery, the PCA rats exhibited marked growth retardation (weight gain of 20 g vs. 140 g for the sham rats; p < 0.001), increased plasma levels of prolactin (9.7 +/- 2.4 vs. 3.6 +/- 0.6; p<0.01) and unaltered growth hormone levels (6.2 +/- 0.5 vs. 8.1 +/- 1.0). A six-fold elevation of histamine concentration (29.5 +/- 3.9 vs. 4.8 +/- 0.4; p<0.001) and a two-fold increase of tele-methylhistamine levels (1.8 +/- 0.1 vs. 0.8 +/- 0.02; p<0.001) were found in hypothalamus. CONCLUSION: We suggest that increased histaminergic activity in the hypothalamus may be involved in the development of growth retardation and in the enhanced basal secretion of prolactin in male rats with long-term PCA.

Brain histamine H3 receptors in rats with portacaval anastomosis: in vitro and in vivo studies.

The long-term effects of portacaval anastomosis (PCA) on histamine H3 receptors in rat brain were studied by in vitro and in vivo methods. The overflow of histamine from the anterior hypothalamus and from cortex after long-term PCA was determined by in vivo microdialysis. The binding properties of [3H]-R-alpha-methylhistamine in membranes from cortex, cerebellum, and rest of brain (ROB) were examined with saturation binding experiments. The regional distribution of [3H]-R-alpha-methylhistamine binding sites in the brain of sham- and PCA-operated rats was assessed also with autoradiography. The tissue levels of histamine were significantly elevated in cortex and ROB of PCA-operated rats. In addition, the spontaneous and K+-evoked overflow of histamine from anterior hypothalamus, and the thioperamide-induced overflow from both anterior hypothalamus and cortex were increased after chronic PCA. In spite of the significantly elevated tissue concentrations and the moderate increase in histamine release, the binding properties of [3HI-R-alpha-methylhistamine to cortical membranes were not significantly changed. However, the autoradiography study did reveal a decrease in [3H]-R-alpha-methylhistamine binding density, particularly in striatum and cortex, where H3 receptors are located mainly at non-histaminergic neurons. In conclusion, we suggest that there is a region-selective increase in the histaminergic activity in chronic PCA, which leads to the down-regulation of somadendritic and pre-synaptic H3 receptors located at non-histaminergic neurons. At the same time, the autoreceptor mediated control of histamine neuronal activity via pre-synaptic H3 receptors located at histaminergic neurons is preserved after long-term PCA.

Behavioral and electroencephalographic studies of beagles with an Eck's fistula: suitability as a model of hepatic encephalopathy.

Behavioral manifestations, electroencephalograms (EEGs) and visually evoked potentials (VEPs) were studied in beagles with Eck's fistula (portacaval shunt [PCS]), an established model of hyperammonemia, to determine whether they developed CNS disorders characteristic of hepatic encephalopathy. After PCS, behavioral changes occurred in the form of listlessness, sluggishness (altered gait, snapping and transient catatonia-like symptoms) and apparent blindness, which appeared in that order and progressed to coma and death in some animals. The EEGs from the frontal cortex showed a gradual decrease in voltage and frequency. Development of snapping and catatonia-like symptoms coincided with the occurrence of high voltage fast waves in the EEGs from the occipital cortex. In comatose Eck's fistula dogs. flattening of the EEGs was recorded from the frontal cortex and a lowered voltage was noted in the EEGs from the occipital cortex. After PCS, the latencies and amplitudes of the components of VEP were increased. The snapping and catatonia-like symptoms were markedly ameliorated by carbamazepine and the coma by flumazenil and thyrotropin-releasing hormone. These findings indicate that Eck's fistula dogs provide a useful model of hepatic encephalopathy.

Iron overload in the rat pancreas following portacaval shunting and dietary iron supplementation.

Reproduction of pancreatic iron overload in an animal model has been difficult to achieve primarily because of the first-pass extraction of iron by the liver. We hypothesized that portacaval shunting would avoid this hepatic phenomenon and increase pancreatic iron deposition. An end-to-side portacaval shunt was surgically created in male Sprague-Dawley rats, and they were subsequently fed a carbonyl iron-supplemented diet for 17 weeks. This resulted in marked iron accumulation in the pancreas (1621 +/- 188 micrograms/g) compared to minimal deposition in sham-operated rats fed the same diet (138 +/- 53 micrograms/g). Iron deposition in the acinar and centroacinar cells was confirmed histologically by Gomori staining, as well as by ultrastructural examination. Iron overloading was associated with enhanced oxidative stress evidenced by a twofold increase in the levels of glutathione disulfide and thiobarbituric acid-reactive substances. Also, adducts of proteins with malondialdehyde and 4-hydroxynonenal were demonstrated in acinar and ductal cells. Other apparent consequences of iron overload were a 50% reduction in pancreatic amylase content and a decrease in pancreatic protein concentration. These hypotrophic changes were associated with a reduced mass of zymogen granules in the acinar cells noted histologically. Our results show that a combination of portacaval shunting and carbonyl iron feeding achieve pancreatic iron overload and support the role of oxidative stress in the pathogenesis of iron-induced damage in the pancreas.

Glutamine, myo-inositol, and organic brain osmolytes after portocaval anastomosis in the rat: implications for ammonia-induced brain edema.

Brain myo-inositol, an organic osmolyte, is decreased in cirrhotic patients with hepatic encephalopathy but appears unchanged in fulminant hepatic failure. An osmoregulatory response to the increase in brain glutamine may explain the decrease in brain myo-inositol; if this is the case, organic osmolytes may account for differences in the development of brain edema seen in acute or chronic liver failure. The response of myo-inositol and nine other organic osmolytes to the increase in brain glutamine at different time intervals after portacaval anastomosis (PCA) in the rat was studied. Organic osmolytes were measured in brain tissue and cerebrospinal fluid. Water in cerebral cortex was measured after ammonia infusion with the gravimetric method. Six weeks after PCA, despite an increase in brain glutamine (PCA, 16.4 +/- 2 mmol.kg wt-1.kg wt-1; sham, 5 +/- 1 mmol.L-1.kg wt-1), the content of total organic osmolytes did not increase (PCA, 44.1 +/- 3; sham, 43 +/- 4) because of a decrease of other osmolytes (myo-inositol, 54%; urea, 39%; taurine, 33%; and glutamate, 8%). Brain myo-inositol was lower at 3 weeks (3.4 +/- 0.5 kg wt-1) than at 1 day after PCA (4.7 +/- 0.5 kg wt-1). An ammonia infusion resulted in brain edema at both time points. In conclusion, the reduction in brain myo-inositol in PCA rats is accompanied by the decrease of other organic osmolytes, supporting the view that changes in myo-inositol reflect an osmoregulatory response. The decrease in brain myo-inositol is more marked as time elapses after PCA. In a model in which short-term and large doses of ammonia were infused, the decrease in brain myo-inositol did not prevent the development of brain swelling. Understanding brain osmoregulatory mechanisms may provide new insights into hepatic encephalopathy and brain edema in fulminant hepatic failure.

Impact of portacaval anastomosis on plasma fatty acid profile in cirrhosis: a randomized 24-month follow-up study.

BACKGROUND: Portacaval anastomosis has an hypolipemic effect in familial hypercholesterolemia and in healthy animals. In cirrhosis, it raises serum cholesterol, but there is no information on its effect upon plasma fatty acids. However, indirect data suggest that portacaval shunting might contribute to the polyunsaturated fatty acid deficit of these patients. We assessed the effect of portacaval anastomosis on plasma fatty acid profile in cirrhosis. METHODS: Forty-four Child-Pugh class A/B bleeding cirrhotics were randomized to be treated with portacaval anastomosis (n = 20) or nonsurgical therapy (n = 24). Fatty acid profile in plasma total lipids, alcohol intake, anthropometry, Child-Pugh score, serum cholesterol, triglycerides, and antioxidant micronutrients were assessed before and 3, 6, 12, 18, and 24 months after surgery or the start of nonsurgical therapy. Time course of plasma fatty acids was assessed using unbalanced repeated measures models with the above mentioned variables acting as covariates. RESULTS: No changes in the time course of percent plasma saturated, monounsaturated, and essential fatty acids were found between groups. Percent long-chain omega-6 and omega-3 polyunsaturated fatty acids decreased during follow-up in shunted patients compared with controls (p = .007 and p < .0005). However, this was not due to a true decrease in polyunsaturated fatty acid levels but to greater increases in saturated and monounsaturated fatty acid concentrations in shunted patients compared with control patients (p = .047 and p = .006). CONCLUSIONS: Portacaval anastomosis does not worsen plasma polyunsaturated fatty acid deficiency in cirrhosis. However, by increasing saturated and monounsaturated fatty acids, it further decreases plasma lipid unsaturation.

Selective alterations of extracellular brain amino acids in relation to function in experimental portal-systemic encephalopathy: results of an in vivo microdialysis study.

Portal-systemic encephalopathy (PSE) is characterized by neuropsychiatric symptoms progressing through stupor and coma. Previous studies in human autopsy tissue and in experimental animal models of PSE suggest that alterations in levels of brain amino acids may play a role in the pathogenesis of PSE. To assess this possibility, levels of amino acids were measured using in vivo cerebral microdialysis in frontal cortex of portacaval-shunted rats administered ammonium acetate (3.85 mmol/kg, i.p.) to precipitate severe PSE. Sham-operated rats served as controls. Portacaval shunting resulted in significant increases of levels of extracellular glutamine (threefold, p < 0.001), alanine (38%, p < 0.01), aspartate (44%, p < 0.05), phenylalanine (170%, p < 0.001), tyrosine (140%, p < 0.001), tryptophan (63%, p < 0.001), leucine (75%, p < 0.001), and serine (60%, p < 0.001). Administration of ammonium acetate to sham-operated animals led to a significant increase in extracellular glutamine and taurine content, but this response was absent in shunted rats. The lack of taurine release into extracellular fluid following ammonium acetate administration in portacaval-shunted rats could relate to the phenomenon of brain edema in these animals. Ammonium acetate administration resulted in significant increases in the extracellular concentrations of phenylalanine and tyrosine in both sham-operated and portacaval-shunted rats. Severe PSE was not accompanied by significant increases in extracellular fluid concentrations of glutamate, aspartate, GABA, tryptophan, leucine, or serine, suggesting that increased spontaneous release of these amino acids in cerebral cortex is not implicated in the pathogenesis of hepatic coma.

Choline acetyltransferase and acetylcholinesterase activities are unchanged in brain in human and experimental portal-systemic encephalopathy.

Activities of choline acetyltransferase, acetylcholinesterase and butyrylcholinesterase were studied in the frontal cortex, temporal cortex, cerebellum and caudate nucleus obtained at autopsy from eight alcoholic cirrhotic patients who died in hepatic coma and from an equal number of age-matched subjects free from hepatic, neurological or psychiatric disorders. Activities of these enzymes were unaltered in the brains of cirrhotics compared to controls. Choline acetyltransferase and cholinesterase activities were also studied in the cerebral cortex, cerebellum, brain stem and striatum of rats four weeks following portacaval anastomosis and their sham-operated controls. Portacaval-shunting did not cause any statistically significant differences in the activities of choline acetyltransferase, acetyl or butyrylcholinesterases. These results argue against a presynaptic cholinergic lesion in human and experimental portal-systemic encephalopathy.

Evidence for intestinal release of absorbed selenium in a form with high hepatic extraction.

Selenium is readily absorbed from the gastrointestinal tract and utilized for synthesis of selenoproteins. Roles of intestine, liver, and selenoprotein P in this process were evaluated. Rats were given 75Se-selenite by stomach tube, and distribution of 75Se was followed for 3 h. A high portal vein plasma-to-hepatic vein plasma ratio of 75Se 15 min after 75Se administration and earlier uptake by liver than by other tissues indicated avid hepatic extraction of absorbed selenium from portal vein blood. The results of gel filtration of plasma taken 15 min after 75Se administration suggested that the 75Se was in the form of small molecules with some affinity for protein. Immunoprecipitation studies using plasma indicated that 75Se began to appear in selenoprotein P between 15 and 30 min after intragastric administration. To evaluate the role of the liver in the fate of absorbed selenium, rats with portacaval shunts, in which absorbed selenium bypasses the liver, were compared with sham-operated rats. After intragastric administration of selenium, uptake by the liver and incorporation into selenoprotein P were diminished in rats with portacaval shunts but kidney uptake and urinary excretion were increased. This suggests that hepatic extraction of absorbed selenium from portal vein blood decreases its entrance into the systemic circulation. The results of this study indicate that intestine releases absorbed selenium into portal blood in a small-molecule form, designated A-Se, which is highly extracted by the liver. The liver takes up A-Se better than other tissues because of a high extraction capacity and the fact that it is the first organ through which the blood from the intestine passes.

Liver damage, voluntary alcohol intake and brain histamine.

Liver dysfunction induced by protocaval anastomosis (PCA) in the rat is associated with a great reduction of hepatic alcohol and aldehyde dehydrogenase activities. Despite this, PCA rats voluntarily drank more alcohol than unoperated rats. When subjected to forced alcohol consumption, shunted rats maintained their exaggerated voluntary alcohol intake whereas unoperated rats developed aversion to alcohol. Hypothalamic levels of both histamine and histidine were very high in PCA rats. When these rats were chronically exposed to alcohol, there was a slight decrease in hypothalamic histidine concentration and consequently a lower histamine content. Chronic exposure to alcohol did not, however, influence hypothalamic tissue levels of histamine or histidine in unoperated rats. In both groups, chronic alcohol treatment exerted a stimulatory effect on hepatic alcohol metabolizing enzymes.

Cyclosporine and liver regeneration studied by in vivo 31P nuclear magnetic resonance spectroscopy.

The changes in fructose-1-phosphate (F-1-P), intracellular pH, and ATP content of the liver after a fructose challenge were investigated noninvasively in vivo using phosphorus-31 nuclear magnetic resonance spectroscopy of dog liver four days after a portacaval shunt (PCS) with or without portal venous infusion of cyclosporin (CsA). The F-1-P metabolism was slower in PCS dogs (N = 2) as compared to either the normal (N = 2) or PCS + CsA-treated dogs (N = 3) (P less than 0.05). The intracellular pH temporarily decreased from 7.3 +/- 0.05 to 7.0 +/- 0.05 during the fructose challenge. The regenerative indexes were increased in the PCS + CsA group (P less than 0.01). These data obtained in vivo using 31P-NMR spectroscopy in the liver following a portacaval shunt, suggest that: (1) the energy status of the liver and the metabolic response to fructose are reduced in PCS compared to normal animals and (2) CsA treatment enhances the regenerative response of the liver and prevents the reduction in hepatic function associated with portacaval shunting.

Effect of cyclosporine on hepatic energy status and on fructose metabolism after portacaval shunt in dog as monitored by phosphorus-31 nuclear magnetic resonance spectroscopy in vivo.

The effect of cyclosporin A on the hepatic energy status and intracellular pH of the liver and its response to a fructose challenge has been investigated using in vivo phosphorus-31 nuclear magnetic resonance spectroscopy in dogs. Three experimental groups were studied: (a) control dogs (n = 5), (b) dogs 4 days after the creation of an end-to-side portacaval shunt (n = 5), and (c) dogs 4 days after portacaval shunt and continuous infusion of cyclosporin A (4 mg/kg/day) by way of the left portal vein (portacaval shunt plus cyclosporin A, n = 5). The phosphorus-31 nuclear magnetic resonance spectra were obtained at 81 MHz using a Bruker BIOSPEC II 4.7-tesla nuclear magnetic resonance system equipped with a 40-cm horizontal bore superconducting solenoid. The phosphomonoesters (p less than 0.01), inorganic phosphate and ATP levels (p less than 0.05) were decreased significantly in portacaval shunt-treated and in portacaval shunt-plus-cyclosporin A-treated dogs compared with unshunted control dogs. After a fructose challenge (750 mg/kg body wt, intravenously), fructose-1-phosphate metabolism was reduced in portacaval shunt-treated dogs compared with either the normal or portacaval shunt-plus-cyclosporin A-treated dogs (p less than 0.05). Both portacaval shunt- and portacaval shunt-plus-cyclosporin A-treated dogs demonstrated a reduced decline in ATP levels after fructose infusion when compared with the controls (p less than 0.05). Immediately after the fructose challenge, the intracellular pH decreased from 7.30 +/- 0.03 to 7.00 +/- 0.05 in all animals (p less than 0.01) and then gradually returned to normal over 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)