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To clarify the nature of nitrogen metabolism between branched chain amino acid (BCAA) and glutamine (GIn) in liver failure, we measured arterial plasma concentrations of GIn and 15N uptake to amino-N and amide-N of GIn in normal and D-galactosamine-induced fulminant hepatic failure (FHF) rats after 15N-leucine (Leu) injection. Fifteen, 30 and 60 min after Leu injection, the arterial plasma concentrations of GIn were significantly higher in FHF rats than in controls. The concentrations of amino-15N GIn were also significantly higher in FHF rats than in controls at 5, 15, 30 and 60 min after injection. The concentrations of amide-15N GIn did not significantly differ between FHF and controls at 5, 15 and 30 min. However, at 60 min, the concentration was significantly higher in the FHF rats. The higher uptake of 15N to amino-N of GIn in FHF rats suggests the presence of an enhanced ability to synthesize GIn from Leu in FHF rats. The higher uptake of 15N to amide-N of GIn in FHF rats at 60 min after injection suggests that excessive administration of BCAA to patients with severely impaired urea-cycle capacity suffering with hepatic failure may lead to greater levels of hyperammonemia.

We administered a branched-chain amino acid (BCAA) infusion to 16 patients with hepatic failure and two healthy subjects, and then evaluated its effects on ammonia metabolism and amino acid metabolic pool. Immediately after the BCAA infusion, the venous blood ammonia concentration increased in 12 of 15 patients with hepatic failure and in both two healthy subjects. Glutamine (Gln) also rose in all cases following the BCAA infusion, and this rise was particularly marked in the hepatic failure group. The increase in Gln due to the BCAA infusion and the arteriovenous difference in the pre-administration ammonia concentration showed a good correlation. These results suggest an increase in glutamine cycle capacity in patients with hepatic failure.

To investigate the role of Kupffer cells in complement activation, we used a rat model of acute hepatic injury induced by D-Galactosamine (GalN) and lipopolysaccharide (LPS). In in vivo study, minimal histological changes were observed after i.p. GalN (200 mg/kg) single administration. Complement hemolytic activity (CH 50) decreased to 70% of its initial value 2-3 h after i.p. LPS (1.5 mg/kg) single administration. Massive hepatic necrosis was induced by simultaneous administration of GalN and LPS. After 2-3 h, CH 50 decreased to 70% of its initial value, and deposition of C3 fluorescence (C3) was observed in Kupffer cells. After 4 h, GPT was greatly increased (1286 +/- 240 IU/l), CH 50 was further reduced, and C3 was observed on hepatocyte membranes and in the cytosol. In in vitro study, we used hepatocyte cultures and co-cultures of hepatocytes and Kupffer cells to investigate the participation of GalN, LPS, complement, and Kupffer cells in hepatic cell necrosis. We found no increase of LDH (% leakage) when LPS and complement were added to the medium (22.7 +/- 5.7%). A moderate increase was observed with the addition of GalN (33.2 +/- 2.6%). A remarkable increase was observed only with the addition of GalN, LPS, and complement to the co-culture (50.0 +/- 8.8%). These results suggest that Kupffer cells activated by LPS are very important in promoting acute hepatic injury by complement.

Experimental hepatocellular carcinoma (HCC) in rats did not take up intravenously administered indocyanine green (ICG) and trypan blue, while surrounding tissue did. The lack of ICG uptake was also observed by peritoneoscopy in patients with HCC. The contrast between ICG-stained cirrhotic nodules and HCC tumors was intensified with infrared photography. Non-uptake of dyes by HCC cells may enable discrimination between tumors and normal cells.

Sex, age and 21 routine liver function assays were analyzed by stepwise selection and the best-of-all-possible-combinations method to identify a small group of assays valuable in establishing which liver cirrhosis (LC) patients have a high risk of hepatocellular carcinoma (HCC), when alpha-fetoprotein (AFP) is not elevated. Data was obtained from 115 HCC and 122 LC patients on admission. Tumor size correlated with AFP (0.73), alkaline phosphatase (ALP, 0.47), leucine aminopeptidase (LAP, 0.42), lactic dehydrogenase (LDH, 0.42), and the glutamic oxaloacetic transaminase (GOT)/glutamic pyruvic transaminase (GPT) ratio (GOT/GPT, 0.41). The mean of the correct diagnosis rates (CDR) of HCC and LC utilizing AFP as the sole parameter (89%) was markedly higher than those of the other parameters. The best-of-all-possible-combinations method presented a more powerful combination than stepwise selection. The best combination of 7 parameters (LAP, GOT/GPT, choline esterase, one-hour erythrocyte sedimentation rate, age, albumin/globulin ratio, and total bilirubin) presented a mean CDR of 80%, HCC CDR of 77%, and false positive rate of 18%. LC patients statistically diagnosed as having HCC by these 7 parameters are proposed as high risk patients. Fourteen (78%) of 18 HCC patients who were AFP-negative were statistically diagnosed. This analysis can be applied to LC patients to distinguish those that should be followed closely by imaging diagnostic techniques.

Computed tomographic arteriography (CTA) was performed in 30 patients with hepatocellular carcinoma (HCC). Detection of HCC by CTA was compared with that of conventional celiac or hepatic arteriography. CT scanning was performed immediately, 30 seconds and 1 min after an injection of 5 to 10 ml of contrast medium into the common or proper hepatic artery. Repeated infusions allowed whole liver sections to be visualized. HCC was localized in 28 of the 30 patients by conventional arteriography, with CTA detecting the masses in 27 of the 28 patients. CTA imaging presented the tumor mass in 1 of the 2 patients missed by arteriography. Conventional arteriography delineated the boundaries of HCC in 15 (50%) of the 30 patients. CTA clearly delineated the masses in 26 (87%) of the 30 patients including 11 patients in which the tumor borders were obscure by conventional arteriography. HCC lesions smaller than 1 cm in diameter were detected only by CTA in 6 (20%) of the patients. It was concluded that CTA is both useful and necessary in the demarcation of small HCC masses.

The whole body including extended processes of Ito's fat-storing cells was observed by scanning electron microscopy in rat liver injured with lithocholic acid (LCA). Necrotic foci developed in the midlobular zone 48 h after LCA administration. Demonstration of Ito cell bodies around the foci was probably facilitated by easy detachment of hepatocytes from Ito cells. The body and the processes were located mainly between the sinusoidal endothelium and hepatocytes; sometimes they were between hepatocytes. Ito cells often were proximate to collagen fiber bundles and sometimes were attached to them. The cell body was flatly round or elliptic, 7 to 12 micron in diameter. Its surface was finely undulated with microvillous projections about 0.1 micron in length. Branching patterns of the processes resembled a fern-leaf mantling the sinusoidal endothelium. The trunks of the processes were about 2 micron in diameter and 20-30 micron in length. These processes tapered, branching into thinner processes, with the most peripheral being 0.1 micron in diameter. Ito cells and their branching processes likely strengthen sinusoidal walls and control blood flow in the sinusoids.

Fulminant hepatic failure (FHF) was produced in rats with intraperitoneal injection of D-galactosamine. Control rats received only physiological saline. 15N-leucine (200 mg/kg of body weight) was injected into the rats via the tail vein. Arterial blood was drawn before and 5, 15, 30 and 60 min after the injection of 15N-leucine. 15N-amino acids were determined quantitatively by gas chromatography and mass spectrometry. The plasma 15N-leucine level decreased logarithmically in the same manner in both groups. This result suggests that leucine is mainly metabolized in extrahepatic tissues. The incorporation of 15N into plasma isoleucine and valine was not significantly different between the groups. Plasma alanine and glutamine concentrations increased in controls and decreased in FHF rates after the injection. The incorporation of 15N into plasma alanine in rats with FHF was significantly later than in controls. This result may suggest that undergoing hyperammonemia causes to form more glutamine from glutamate in extrahepatic sites as the same manner as for chronic hepatic failure. Additionally, insulin levels increased temporarily after the injection of leucine in both groups. This increase may play a role in the decrease in plasma isoleucine and valine concentrations after injection of leucine.

Three linear plots by which the liver's maximum removal rate (Rmax) of indocyanine green (ICG) and the Michaelis constant (Km) can be calculated were compared in a microcomputer simulation study. The widely-used Lineweaver-Burk plot (1/V vs. 1/S; V, ICG initial removal rate (mg/kg/min); S, ICG loading dose (mg/kg] presented the greatest bias and variance. There was no remarkable difference in bias between the S/V vs. S plot and the V vs. V/S plot, but the latter possessed a smaller variance. Therefore, the V vs. V/S plot was considered the best for estimating Rmax. The best combination of three ICG loading doses was 0.5, 2, and 5 mg/kg. This combination was selected by comparison of the Rmax estimated from three points with that estimated from six points (0.5, 1, 2, 3, 4 and 5 mg/kg).