Takaya Sawamura

Lactulose-L-rhamnose intestinal permeability test in patients with liver cirrhosis

A lactulose-L-rhamnose intestinal permeability test was conducted on 35 patients with liver cirrhosis and six normal controls. Gas chromatography was used to measure lactulose and L-rhamnose concentrations in blood and urine specimens. The excretion of each molecule was expressed as the percentage of the orally administrated dose and the lactulose-L-rhamnose ratio as the ratio of the percentage of each probe molecule excreted. The mean 8-h lactulose excretion ratios were 0.56 and 0.16% in patients with liver cirrhosis and the control subjects, respectively (P<0.05), whereas the corresponding excretion ratios for L-rhamnose were 4.40 and 3.49%. The mean lactulose-L-rhamnose excretion ratios in patients with liver cirrhosis and the control subjects were 0.124 and 0.049, respectively (P<0.05). The lactulose-L-rhamnose excretion ratio increased in patients with liver cirrhosis complicated by large intestinal vascular ectasia of the large intestine or rectal varices, which were used as parameters for evaluating the effects of portal hypertension on the lower digestive tract. These results suggest that an increase in lactulose intestinal permeability in patients with liver cirrhosis proves the effects of portal hypertension extending to the lower digestive tract.

Clinical application of the measurement of serum asialoglycoproteins to estimate residual liver function in patients with chronic liver diseases with or without hepatocellular carcinoma

SummaryThe correlation between the amount of asialoglycoproteins and results of conventional liver function tests was studied in patients with chronic liver diseases, with or without hepatocellular carcinoma. The objective was to determine the clinical significance of the measurement of levels of serum asialoglycoproteins. The levels were elevated in accordance with the progress of liver diseases, and correlated with the decrease in albumin content, cholinesterase activity, the ratio of esterified cholesterol to total cholesterol and to the increase of indocyanine green retention at 15 min (p<0.001). There was no correlation with values of glutamic oxaloacetic and pyruvic transaminases. The amount of serum asialoglycoproteins also correlated with survival time in fatal cases of cirrhosis and/or hepatocellular carcinoma.Bilirubin and bile acids did not interfere with the measurement of serum asialoglycoproteins in cases of hyperbilirubinemia.Serum asialoglycoprotein levels are a good indicator of hepatic functional reserve in patients with chronic liver diseases, with or without hepatocellular carcinoma.

Phosphorylation of the rat hepatocyte asialoglycoprotein receptor

Phosphorylation of asialoglycoprotein receptor was investigated by using rat hepatocytes. Analysis of the purified receptor by SDS-PAGE and autoradiogram revealed that the 64 and 54 Kd polypeptides of the receptor were phosphorylated but the 43 Kd one was not and that phosphorylation took place at the cell surface. These results are compatible with the fact that the 64 and 54 Kd species exist predominantly at the cell surface. The sites of phosphorylation were identified as Ser and Thr with no detectable radioactivity in phosphotyrosine.

Localization of nascent NADPH-cytochrome c reductase in rat liver microsomes

Rat liver microsomes incubated with [3H] puromycin in high salt buffer were digested with a mixture of protease, trypsin and chymotrypsin, in both the presence and absence of 1 % deoxycholate. Our observations revealed that the proteolysis of peptidyl puromycin labeled with [3H] puromycin was at least partially protected by the presence of microsomal membrane. Immuno-chemical analyses have further shown that most of the nascent NADPH-cytochrome c reductase in the microsomes was digested with the proteases while serum albumin was effectively protected from the digestion. It is thus proposed that NADPH-cytochrome c reductase synthesized on the membrane bound ribosomes is not transported to the vesicular cavity but directly to the outer surface of the microsomal membrane in a form which is accessible to the proteases.