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Cellular senescence induces inflammation and is now considered one of the causes of organismal aging. Accumulating evidence indicates that age-related deterioration of mitochondrial function leads to an increase in reactive oxygen species (ROS) and DNA damage, which in turn causes cellular senescence. Thus, it is important to maintain mitochondrial function and suppress oxidative stress in order to inhibit the accumulation of senescent cells. Sesamin and its isomer episesamin are types of lignans found in sesame oil, and after being metabolized in the liver, their metabolites have been reported to exhibit antioxidant properties. However, their effects on cellular senescence remain unknown. In this study, the effects of sesamin, episesamin, and their metabolites SC1 and EC1-2 on replicative senescence were evaluated using human diploid lung fibroblasts, and TIG-3 cells. The results showed that sesamin and episesamin treatment had no effect on proliferative capacity compared to the untreated late passage group, whereas SC1 and EC1-2 treatment improved proliferative capacity and mitigated DNA damage of TIG-3 cells. Furthermore, other cellular senescence markers, such as senescence-associated secretory phenotype (SASP), mitochondria-derived ROS, and mitochondrial function (ROS/ATP ratio) were also reduced by SC1 and EC1-2 treatment. These results suggest that SC1 and EC1-2 can maintain proper mitochondrial function and suppress the induction of cellular senescence.

Background: The age of patients with advanced hepatocellular carcinoma (HCC) eligible for molecular-targeted drug treatment is increasing. We assessed liver function after lenvatinib administration according to age in patients with advanced HCC., Patients and Methods: In this retrospective, multicenter, observational study, we reviewed the records of patients with HCC who received lenvatinib treatment (March 2018-March 2020). Liver function was measured using the Albumin-Bilirubin Index (ALBI)., Results: Of 119 patients, with a median age of 72.0 years, median overall survival was 15.3 months. Overall survival was significantly better in the group which maintained liver function (p=0.02). Older age (≥72 years) was associated with liver-function deterioration within 8 weeks (odds ratio=2.47, 95% confidence interval=1.06-5.75, p=0.035). The ALBI score was significantly higher in the older group at 4 and 8 weeks after lenvatinib administration., Conclusion: Lenvatinib administration was more likely to adversely affect liver function in older patients; dose adjustment should be considered in such patients., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background/aim: To evaluate the complication rates and risk factors associated with transumbilical wounds and investigate the usefulness of an incision for organ removal in laparoscopic hepatectomy (Lap-H)., Patients and Methods: We enrolled 42 patients who underwent Lap-H excluding a small partial resection in our hospital between 2013 and 2018. The occurrences of superficial surgical site infection (SSI) and transumbilical port-site incisional hernia were recorded., Results: SSI was not observed, and hernia occurred in 3 patients (7.14%). Univariate analysis revealed that body mass index (BMI) (p=0.004) was significantly associated with the risk of hernia formation., Conclusion: High BMI is a risk factor for hernia formation in patients undergoing Lap-H with transumbilical incision; hence, wound closure should be performed carefully. The construction of the transumbilical wound for organ removal was feasible with rationality, with no need to create a new wound., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Non-alcoholic fatty liver disease (NAFLD) is a significant problem because its prevalence is increasing worldwide. Recent animal studies have identified gut microbiota as a potentially important player in the pathogenesis of NAFLD. Previously, we reported that the administration of branched-chain amino acids (BCAAs) reduces hepatic fat accumulation in experimental animal models. This study aimed to clarify how changes in the intestinal microbial flora following the administration of BCAAs affect a high-fat diet (HF)-induced fat accumulation in the liver. We examined whether the administration of BCAAs alters the development of hepatic fat accumulation as well as intestinal microbial flora. The oral administration of BCAAs (3% kcal) induced a significant increase in Ruminococcus flavefaciens (R. flavefaciens) and portal acetic acid levels, and it reduced hepatic fat accumulation in HF-fed rats. In addition, BCAAs reduced the expression of the lipogenesis-related genes FAS and ACC in the liver. Furthermore, we observed that R. flavefaciens is essential for promoting a BCAA-induced reduction in hepatic fat accumulation. These data suggest that BCAA treatment induces the proliferation of intestinal flora including R. flavefaciens and that portal acetic acid synthesized from intestinal flora improves NAFLD by downregulating the expression of FAS and ACC in the liver.

Polyunsaturated fatty acids (PUFAs), especially arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), play an important role in biological regulation. In our previous study using mice deficient in Δ6 desaturase (D6D), we reported that ARA is required for body growth, while DHA is necessary for functional development. In mammals, ARA and DHA are supplied directly or by synthesis from linoleic acid (LA) and α-linolenic acid (ALA). However, as desaturase enzyme activity is immature or low in newborns, and humans with minor alleles of the gene encoding desaturase, respectively, they require dietary supplementation with ARA and DHA. To investigate how the body reacts to a long-term reduction in fatty acid synthesis, we measured behavioral changes and fatty acid composition in mice heterozygous for the D6D null mutation with reduced D6D activity fed a diet containing only LA and ALA as PUFAs. During the growth-maturity period, heterozygous mice showed a slightly change in interest and curiosity compared with the wild-type group. ARA levels were decreased in the brain and liver in the heterozygous group, especially during the growth-maturity period, whereas DHA levels were decreased in the liver only in the old age period, suggesting that there are differences in the synthesis of and demand for ARA and DHA during life. For newborns, and humans with minor alleles with low desaturase activity, direct ARA intake is particularly important during the growth-maturity period, but they may need to be supplemented with DHA in the old age period. Further research is needed to determine the optimal intake and duration of these fatty acids., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background/aim: Lenvatinib (LEN) has been developed for the treatment of unresectable hepatocellular carcinoma (u-HCC). We aimed to elucidate the relative change in hepatic reserve function early following LEN treatment in affected patients., Materials/methods: From March 2018 to April 2019, 123 u-HCC patients (median age 71 years; male:female ratio 95:28; Child-Pugh score 5:6:7 = 65:50:8; modified albumin-bilirubin [mALBI] grade 1:2a:2b:3 = 44:28:50:1, Barcelona Clinic Liver Cancer stage A:B:C = 1:49:73) were enrolled. Relative changes in hepatic reserve function at 2 and 4 weeks after starting LEN were retrospectively evaluated., Results: The median survival was 11.3 months. The Child-Pugh score declined from the start to 4 weeks after commencing LEN (score 5:6:7:8:9:≥10 = 65:50:8:0:0:0 vs. 50:39:22:8:0:4, p < 0.001). A comparison among ALBI scores at the start of LEN and those at 2 and 4 weeks revealed significant relative changes (-2.36 ± 0.45 to -2.20 ± 0.49 at 2 weeks, -2.15 ± 0.50 at 4 weeks, p < 0.001, Bonferroni method), while there was no significant difference between those at 2 and 4 weeks (p= 0.210, Bonferroni method). Assessments of relative changes of ALBI score in patients divided by mALBI grade 1, 2a, and 2b or more showed a significant decline in score regardless of grade (-2.82 ± 0.17 to -2.53 ± 0.34, p < 0.001; -2.46 ± 0.10 to -2.31 ± 0.33, p = 0.017; and -1.90 ± 0.26 to -1.75 ± 0.42, p= 0.009, respectively)., Conclusion: Decline in hepatic function is common in the early stage (≤4 weeks, especially within 2 weeks) after introducing LEN. It is important to introduce molecular targeting agent drugs for u-HCC in patients with better hepatic function, who show transarterial catheter chemoembolization failure, as much as possible, along with consideration of the negative influence of LEN on the early response of hepatic function., (© 2019 S. Karger AG, Basel.)

We herein report a child case of autoimmune hepatitis (AIH) accompanied with Graves' disease. Elevated aminotransferase levels were found in a 12-year-old Japanese girl with Graves' disease. In her first liver biopsy, necrosis and inflammation was limited to the centrilobular area, while the second biopsy showed different findings. Namely, portal injury newly appeared, including interface hepatitis, which represents the histological characteristics of AIH. As the histological findings at the onset of AIH do not always show typical findings, a re-biopsy is considered to be important in individuals suspected to have AIH. AIH should be included in the differential diagnosis of liver dysfunction in Graves' disease, even in children.

The liver biopsy remains a valuable tool in the diagnosis of drug-induced liver injury (DILI). The Digestive Disease Week Japan 2004 (DDW-J) scale proposed as an objective tool for the diagnosis of DILI has been widely used in Japan. So far, the histological features have not been compared with DDW-J scale in detail. Herein, we examined the correlation between liver biopsy findings and clinical features, particularly DDW-J scales. A total of 80 patients with liver injuries of unknown cause were enrolled. Based on the histological findings, these cases were categorized into 3 groups: A (DILI was strongly suspected), B (DILI was suspected), and C (DILI should be considered in the differential diagnosis). Histological groups and DDW-J scale were moderately correlated (κ = 0.60). The mean total DDW-J scale scores were as follows: 4.89 for A, 3.26 for B, and 0.75 for C (p < 0.05). While hepatocellular type was coincided in a majority of cases by histological and DDW-J scale evaluation, cholestatic type was not well coincided. In conclusion, biopsy findings and DDW-J scale were well correlated, and the hepatocellular type of liver injuries was well coincided by both evaluations, though there were several discrepant cases, particularly in cholestatic type.

Background & Aims: Non-alcoholic fatty liver disease (NAFLD) is believed to be a type of metabolic syndrome. MicroRNA-122 (miR-122) is the most abundant microRNA in the liver and is an important factor for the metabolism of glucose and lipids. In the present study, we examined the correlation between the hepatic and serum miR-122 expression levels and the clinicopathological factors of patients with NAFLD., Methods: We extracted the total RNA, along with preserved miRNAs, from liver biopsy samples of 67 patients with NAFLD. In 52 of these 67 patients, the total RNA was extracted from serum. The miR-122 that was obtained by quantitative reverse transcription-polymerase chain reaction was quantified using TaqMan MicroRNA assays., Results: A significant correlation was detected between serum and hepatic miR-122 expression (correlation coefficient, 0.461; P=0.005). Patients with mild steatosis (<33%) showed significantly lower levels of hepatic miR-122 compared with patients with severe steatosis (>33%) (hepatic miR-122: mild/severe=2.158±1.786/4.836±7.506, P=0.0473; serum miR-122: mild/severe=0.002±0.005/0.007±0.001, P=0.0491). Moreover, hepatic and serum miR-122 levels were significantly higher in patients with mild fibrosis than in those with severe fibrosis (hepatic miR-122: mild/severe=5.201±7.275/2.394±1.547, P=0.0087; serum miR-122: mild/severe=0.008±0.011/0.002±0.004, P=0.0191)., Conclusions: We found that the hepatic and serum miR-122 levels were associated with hepatic steatosis and fibrosis. The serum miR-122 level can be a useful predictive marker of liver fibrosis in patients with NAFLD., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Antioxidative effects of sesamin (a mixture of sesamin and episesamin) were evaluated in the liver, kidney and inferior vena cava of living rats using a radiofrequency ESR method. TEMPOL, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl, was used as an in vivo redox probe, the half-life of which is believed to be correlated with the antioxidant status. The oral administration of sesamin (250 mg/kg rat weight) 3 h before ESR measurements shortened the half-life of TEMPOL in the liver by 10 - 15% as compared with the controls, but did not affect the other organs. This effect was maintained for at least 3 h after the administration, and then disappeared at 24 h, corresponding to the results of our preliminary pharmacokinetic studies. Changes in the reducing ability were observed only in the hepatic sites of the sesamin-treated rats. These findings suggest that sesamin exhibits effective antioxidant activity in the liver via modulation of the intracellular redox status related to TEMPOL reduction.

Objective: Signal transducers and activators of transcription (STATs) play a critical role in antiviral defense. To better understand pegylated interferon (IFN)-alpha and ribavirin combination therapy resistance, we examined the STAT expression in the liver., Methods: We immunostained Phospho-STAT1 (P-STAT1) and Phospho-STAT3 (P-STAT3) in 59 hepatitis C virus (HCV)-infected liver tissues and compared the expression of these STATs proteins and the clinicopathological factors., Results: The number of P-STAT1 observed correlated significantly with the body mass index (BMI; p = 0.03) and homeostatic model assessment (p = 0.007). The number of P-STAT3 observed correlated significantly with the ALT level (p = 0.002) and platelet count (p = 0.002). The number of P-STAT1 nuclei in the sustained virological response (SVR) group was significantly larger than in the non-SVR group (p = 0.003). On multivariance analysis, the number of P-STAT1 nuclei (p = 0.004) and age (p = 0.016) were significant predictors of SVR., Conclusions: P-STAT1 in the liver tissue prior to IFN therapy correlated with an increased BMI and increased insulin resistance, and might be a useful predictor of HCV clearance by IFN therapy. On the other hand, P-STAT3 might play a critical role in the hepatocellular response against inflammatory damage., (Copyright 2009 S. Karger AG, Basel.)

Intraportal serotonin infusion enhances net hepatic glucose uptake (NHGU) during glucose infusion but blunts nonhepatic glucose uptake and can cause gastrointestinal discomfort and diarrhea at high doses. Whether the serotonin precursor 5-hydroxytryptophan (5-HTP) could enhance NHGU without gastrointestinal side effects during glucose infusion was examined in conscious 42-h-fasted dogs, using arteriovenous difference and tracer ([3-3H]glucose) techniques. Experiments consisted of equilibration (-120 to -30 min), basal (-30 to 0 min), and experimental (EXP; 0-270 min) periods. During EXP, somatostatin, fourfold basal intraportal insulin, basal intraportal glucagon, and peripheral glucose (to double the hepatic glucose load) were infused. In one group of dogs (HTP, n = 6), saline was infused intraportally from 0 to 90 min (P1), and 5-HTP was infused intraportally at 10, 20, and 40 microg x kg(-1) x min(-1) from 90 to 150 (P2), 150 to 210 (P3), and 210 to 270 (P4) min, respectively. In the other group (SAL, n = 7), saline was infused intraportally from 0 to 270 min. NHGU in SAL was 14.8 +/- 1.9, 18.5 +/- 2.3, 16.3 +/- 1.4, and 19.7 +/- 1.6 micromol x kg(-1) x min(-1) in P1-P4, whereas NHGU in 5-HTP averaged 16.4 +/- 2.6, 18.5 +/- 1.4, 20.8 +/- 2.0, and 27.6 +/- 2.6 micromol x kg(-1) x min(-1) (P < 0.05 vs. SAL). Nonhepatic glucose uptake (micromol x kg(-1) x min(-1)) in SAL was 30.2 +/- 4.3, 36.8 +/- 5.8, 44.3 +/- 5.8, and 54.6 +/- 11.8 during P1-P4, respectively, whereas in HTP the corresponding values were 26.3 +/- 6.8, 44.9 +/- 10.1, 47.5 +/- 11.7, and 51.4 +/- 13.2 (not significant between groups). Intraportal 5-HTP enhances NHGU without significantly altering nonhepatic glucose uptake or causing gastrointestinal side effects, raising the possibility that a related agent might have a role in reducing postprandial hyperglycemia.

Objective: We previously found that ingested cocoa decreased visceral adipose tissue weight in rat. To elucidate the molecular mechanisms of that effect, we carried out experiments aimed at analyzing biochemical parameters and gene expression profiles., Methods: Rats were fed either of two high-fat diets, differing only in supplementation with real or mimetic cocoa. On day 21, body weights, mesenteric white adipose tissue weights, and concentrations of serum triacylglycerol were measured. To investigate the molecular mechanisms underlying the effects of cocoa on lipid metabolism and triacylglycerol accumulation, we examined gene expression profiles in liver and mesenteric white adipose tissues using the GeneChip microarray system., Results: Final body weights and mesenteric white adipose tissue weights were significantly lower in rats fed the real cocoa diet than in those fed the mimetic cocoa diet (P<0.05), and serum triacylglycerol concentrations tended to be lower in rats fed the real cocoa diet (P=0.072). DNA microarray analysis showed that cocoa ingestion suppressed the expression of genes for enzymes involved in fatty acid synthesis in liver and white adipose tissues. In white adipose tissue, cocoa ingestion also decreased the expression of genes for fatty acid transport-relating molecules, whereas it upregulated the expression of genes for uncoupling protein-2 as a thermogenesis factor., Conclusions: Ingested cocoa can prevent high-fat diet-induced obesity by modulating lipid metabolism, especially by decreasing fatty acid synthesis and transport systems, and enhancement of part of the thermogenesis mechanism in liver and white adipose tissue.

Aims: To determine whether the presence of large intrahepatic blood vessels (>/=3 mm) affect radiofrequency (RF)-induced coagulation necrosis, the gross and histological characteristics of RF-ablated areas proximal to or around vessels were examined in normal pig livers., Methods: An RF ablation treatment using a two-stepwise extension technique produced 12 lesions: six contained vessels (Group A), and the other six were localized around vessels (Group B)., Results: Gross examination revealed that the longest and shortest diameters of the ablated lesions were significantly larger in Group B than in Group A. In Group A, patent vessels contiguous to the lesion were present in a tongue-shaped area, whereas the lesions in Group B were spherical. Staining with nicotinamide adenine dinucleotide diaphorase was negative within the ablated area; but, if vessels were present in the ablated area, the cells around the vessels in an opposite direction to the ablation were stained blue., Conclusions: Roll-off can be achieved with 100% cellular destruction within a lesion that does not contain large vessels. The ablated area was decreased in lesions that contained large vessels, suggesting that the presence of large vessels in the ablated area further increases the cooling effect and may require repeated RF ablation treatment to achieve complete coagulation necrosis.

Sesamin, a major lignan in sesame oil, is known to have many biological activities, especially protective effects against oxidative damage in the liver. As sesamin itself has no antioxidative properties in vitro, to elucidate the mechanism of its antioxidative effects, the reaction products of sesamin in rat liver homogenate were analyzed. The methylenedioxyphenyl moiety in the structure of sesamin was shown to be changed into a dihydrophenyl (catechol) moiety. The enzymatic reaction products in vitro were identified as (1R,2S,5R,6S)-6-(3,4-dihydroxyphenyl)-2-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3,3,0]octane and (1R,2S,5R,6S)-2,6-bis(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3,3,0]octane, which showed strong radical scavenging activities; the latter was a novel compound. The same metabolites were found as glucuronic acid and/or sulfic acid conjugates in substantial amounts in rat bile after oral administration of sesamin. It is suggested that sesamin is a prodrug and the metabolites containing the catechol moieties in their structures are responsible for the protective effects of sesamin against oxidative damage in the liver.

Background/aim: Follistatin is an antagonist of activins and is effective in promoting liver regeneration after 70% hepatectomy. To examine its efficacy under more critical conditions, we studied the effect of follistatin on liver regeneration in 90% hepatectomized rat., Methods: Human recombinant follistatin was infused into the portal vein immediately after 90%, hepatectomy in 24-h-starved rats, and changes in the liver regeneration rate and nuclear bromodeoxyuridine labeling were measured., Results: In control rats, nuclear labeling was first detected at 11 h of hepatectomy. In follistatin-treated rats, nuclear labeling was markedly increased at 3 h, and was significantly higher than that in control rats at 24, 72, 96, 120 and 144 h. The liver regeneration rate was significantly higher in follistatin-treated rats at 48, 72, 96, 120, 144 and 168 h. To determine the reason for the accelerated growth in starved rats, we compared the expression of mRNA for c-myc, p53, p21CIP1, p15INK4B, p27KIP1, and subunits of activins in fed and starved rats. mRNA for p21CIP1 and p15INK4B, but not p27KIP1 were decreased in 24 h-starved rats compared to the fed rats. mRNA for betaA subunit of activin was not detected in either fed or 24-h-starved rats, whereas that for betaC subunit was increased in starved rats., Conclusion: These results indicate that follistatin induces immediate onset of DNA synthesis in 90% hepatectomized rats and is quite effective in promoting liver regeneration.

To utilize hepatocytes for insulin-producing surrogate cells, we devised a regulatory secretion system by placing proinsulin DNA under the regulatable promoter for phosphoenolpyruvate carboxykinase (PEPCK). The expression of PEPCK is down-regulated by insulin, and up-regulated by cAMP and glucagon. To express insulin in hepatocytes, we constructed an adenoviral insulin expression system. After infection, the hepatocytes secreted immunoreactive insulin (IRI) at an increasing rate. IRI secretion increased over four-fold upon stimulation with 300 microM cAMP and 500 microM of the cAMP-dependent phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX). This increase was also observed with glucagon and IBMX. Production was augmented two-fold by the addition of wortmannin, phosphatidylinositol (PI)-3-kinase inhibitor, suggesting that inhibitory insulin signaling to the PEPCK promoter may be mediated through PI-3-kinase. Addition of exogenous insulin to the culture decreased insulin mRNA expression remarkably on Northern blot. Thus, by using a PEPCK promoter for insulin expression, we were able to up-regulate insulin production from hepatocytes with cAMP and glucagon, and down-regulate with insulin itself.

To elucidate the regulation of follistatin production in the liver, we studied changes in steady-state follistatin mRNA levels in cultured rat hepatocytes. Activin A stimulated follistatin mRNA levels in a time- and concentration-dependent manner. The stimulatory effect of activin A on follistatin mRNA was significant at 2 h, maximal at 6 h and declined thereafter. Incubating the cells with EGF increased follistatin mRNA levels at 48 h and later. The EGF-induced increase in follistatin mRNA was markedly inhibited by exogenous follistatin in the culture medium, which blocks the action of activin A synthesized in hepatocytes, suggesting that endogenous activin A at least partly mediated the effect of EGF. We also examined the effects of transforming growth factor-beta (TGF-beta), glucagon and alpha-adrenergic agonist, phenylephrine, on follistatin mRNA levels. TGF-beta increased the follistatin mRNA to levels similar to those caused by activin A. Phenylephrine and glucagon also increased follistatin mRNA levels but the effects were transient and weaker than those caused by activin A. Finally, follistatin mRNA levels were markedly increased in remnant liver 3 h after 70% hepatectomy. The mRNA remained elevated for up to 72 h. These results indicate that the expression of mRNA for follistatin is positively controlled by activin A, TGF-beta and other hormones or neurotransmitters. The stimulatory effect of EGF on follistatin mRNA is mediated by activin A released from hepatocytes.

Messenger RNA expression of activin betaC subunit in the liver was compared with that for betaA subunit before and after 70% hepatectomy. mRNA for betaC was abundantly expressed in the liver but decreased at 12 h and later after 70% hepatectomy, whereas that for betaA was increased 12 h after the hepatectomy. We also compared the expression of mRNA for betaA and betaC in cultured rat hepatocytes. mRNA for betaC subunit was abundantly expressed in the beginning of the culture but was reduced gradually after stimulation with epidermal growth factor. In contrast, mRNA for betaA subunit was undetectable before stimulation and was increased 24 to 48 h after stimulation with the mitogen. These results indicate that expression of mRNA for betaC and betaA is regulated differently. The role of activin C may be different from that of activin A in the liver.

The present study was conducted to determine the role of two autocrine factors, activin A and transforming growth factor beta (TGF-beta), in the growth regulation of AML12 hepatocytes. We overexpressed truncated type II activin and/or TGF-beta receptors in AML12 cells. In AML12 cells overexpressing truncated type II activin receptors (AML-tAR cells), the inhibitory effect of activin A on DNA synthesis was completely blocked. AML-tAR cells proliferated faster than parental cells, both in the presence and absence of epidermal growth factor (EGF). However, AML-tAR cells could not grow in soft agar. Follistatin augmented EGF-induced DNA synthesis in AML12 cells, whereas it was ineffective in AML-tAR cells. In AML12 cells overexpressing truncated type II TGF-beta receptor (AML-tTR cells), the inhibitory effect of TGF-beta on DNA synthesis was blocked. AML-tTR cells proliferated faster than parental cells, both in the presence and absence of EGF, but at a slower rate than that of AML-tAR cells. AML-tTR cells did not grow in soft agar. The growth rate of cells overexpressing both types of truncated receptors was identical to that of AML-tAR cells, and these cells did not grow in soft agar. These results indicate that both activin A and TGF-beta act as autocrine inhibitors of DNA synthesis in AML12 cells, and that the blocking of the actions of two factors does not lead to transformation. Activin A is a predominant autocrine factor in these cells.

Activin A stimulates glucose production by causing glycogenolysis in isolated hepatocytes. To determine the physiological significance of this effect, we examined the effect of activin A on glucose production in the perfused liver. Unlike the effect in isolated cells, activin A did not enhance glucose production nor did it cause radiocalcium efflux in the perfused liver. There was no effect of activin A in the liver perfused in the opposite direction. Although activin A did not promote glucose production, it was recovered from the hepatic vein in a bioactive form. When liver perfusion was performed in partially hepatectomized rats, activin A increased radiocalcium efflux. In isolated hepatocytes, activin A increased inositol phosphates, and the effect of activin A was attenuated by the plasma membrane fraction of hepatocytes. The inhibitory effect of the plasma membrane was abolished by digestion of the membrane with trypsin. These results indicate that the effect of activin A on glucose production is attenuated in the intact liver and that a protein factor(s) in plasma membrane may be involved in the inhibition.

Tumor-associated aldehyde dehydrogenase (ALDH) was reported in cases of human hepatocellular carcinoma and animal hepatoma models. This ALDH isozyme is similar to ALDH3 which exists in the stomach and lung; however, the biochemical and clinical significance of this unique ALDH isozyme have not been established. Human tumor-associated ALDH was purified, and polyclonal antibodies prepared. Using these antibodies, specific development of tumor-associated ALDH was confirmed by immunohistochemical techniques. It was found that about 50% of hepatocellular carcinomas reacted with the antibody. This unique ALDH isozyme may be a novel tumor marker of hepatocellular carcinoma.

The present study was conducted to examine the effect of activin A on growth of rat hepatocytes. EGF induced a 10-fold increase in DNA synthesis as assessed by [3H]thymidine incorporation in cultured hepatocytes. When activin A was added together with EGF, DNA synthesis induced by EGF was markedly inhibited. Inhibition was detected at a concentration of 10(-10) M, and 5 x 10(-9) M activin A almost completely blocked EGF-mediated DNA synthesis. Similarly, activin A completely blocked DNA synthesis induced by hepatocyte growth factor/scatter factor. Activin A was capable of inhibiting EGF-mediated DNA synthesis, even when added 36 h after the addition of EGF. With the same time interval, TGF-beta also blocked EGF-induced DNA synthesis. Although both activin A and TGF-beta inhibited growth of hepatocytes in a similar manner, either activin A or TGF-beta did not compete with each other in their binding when assessed by competitive binding using an iodinated ligand. When hepatocytes were incubated with EGF, release of bioactivity of activin A into culture medium was detected after 48 h or later. Activity of activin A was released from parenchymal cells but not from nonparenchymal cells. mRNA for beta A subunit of activin was detected only slightly in unstimulated hepatocytes, but markedly increased at 48 h after the addition of EGF. To determine whether endogenously produced activin A affects DNA synthesis, we examined the effect of follistatin, an activin-binding protein that blocks the action of activin A. An addition of follistatin significantly enhanced EGF-induced DNA synthesis. Finally, in partial hepatectomized rat, expression of mRNA for beta A subunit in liver was markedly increased 24 h after the partial hepatectomy. These results indicate that activin A inhibits initiation of DNA synthesis in hepatocytes by acting on its own receptor and that activin A acts as an autocrine inhibitor of DNA synthesis in rat hepatocytes.

The insulin-sensitive cAMP phosphodiesterase (PDE) from rat adipocytes was stimulated 60-70% upon incubation with 2 mM ATP and the soluble fraction (Fraction S-1) from insulin-treated rat liver. The effect of ATP was partially mimicked by ATP-gamma-S or GTP, but not by AMP-PNP. The PDE-stimulating activity in Fraction S-1 was preserved in the presence of 50 mM sodium phenyl phosphate, 50 mM sodium fluoride, and 0.1 mM sodium vanadate. The PDE-stimulating activity was not inhibited with either 0.5 mM H-7 or 5 microM PKI-(5-24)-peptide, but was blocked with 1 mM Kemptide. The active component in Fraction S-1 may be a phosphorylated compound, which, in the presence of ATP, may mediate the hormonal action on PDE.

Estradiol benzoate (EB), a synthetic estrogen, was injected to macronodular cirrhotic rats, and the reversibility of the lesion was investigated. Macronodular liver cirrhosis (MNLC) was produced by use of carbon tetrachloride plus 3'-Me-DAB. In animals with no treatment, regenerative nodules remained unchanged during an eighteen-week observation period. Microangiograms showed markedly deranged intrahepatic microvasculatures, including an irregularly contoured vascular tree and rarefaction in the peripheral area. On the other hand, EB treatment exerted conspicuous efficacy on the above-mentioned intrahepatic microcirculatory disorder and on sinusoidal dilatation, which led the livers with MNLC to revert to almost normal appearance. It is concluded that EB provides a salutary effect on the intrahepatic microcirculatory system, by means of which MNLC can be shown to be a reversible lesion.

The effect of DL-ethionine (EthN) on the blood clearance of 99mTc-phytate (99mTc-P) in dogs was examined, and the blood clearance test of 99mTc-P was compared with the cases of the serum transaminase and bilirubin test. Serum transaminase and bilirubin levels in dogs increased dose-dependently after the administration of EthN. The disappearance rate of 99mTc-P from blood in dogs decreased with the increase in dose of EthN and with the passage of time after EthN administration. Changes of the blood clearance of 99mTc-P after EthN treatment in dogs may be influenced by the disorder in the hepatocytes. The blood clearance test of 99mTc-P in dogs showed a reaction for the acute hepatic dysfunction induced by EthN equally to the serum transaminase and bilirubin test.

The effect of alpha-naphthylisothiocyanate (ANIT) on blood clearance of 99mTc-phytate (99mTc-P) in dogs was examined, and blood clearance test of 99mTc-P was compared with the cases of serum transaminase test or serum bilirubin test. Serum transaminase and bilirubin levels in dogs increased after ANIT administration, however, the degree of increase in these parameters was much lower than the cases in rats. The disappearance rate of 99mTc-P from blood in dogs decreased with the increase in dose of ANIT and with the passage of time after the ANIT administration. Changes of the blood clearance of 99mTc-P after ANIT treatment in dogs may be influenced by the disorder in the hepatocytes rather than in the bile ductule cells. The blood clearance test of 99mTc-P in dogs showed a sensitive reaction for the acute hepatic dysfunction induced by ANIT equally to the serum transaminase test or the serum bilirubin test.

The effect of obesity and jejunoileal bypass on the amount and composition of hepatic lipid and the relationship of adipose tissue fatty acids, body weight, and rate of weight reduction to hepatic triglyceride (TG) were investigated in 16 patients before and at various times after jejunoileal bypass. Liver and adipose tissue biopsy sections were taken at surgery and at various times thereafter. Hepatic lipid was measured and the composition of triglyceride fatty acids (TGFA) compared with that of adipose tissue. Liver TG increased by an average of 2.5-fold during the period of rapid weight loss and decreased during the period of stable weight, but remained above control values. There was no relationship between concentration of liver TG and body weight or rate of weight reduction. The hepatic TGFA composition at surgery and during the period of stable weight resembled that of adipose tissue. During the period of rapid weight loss the composition of hepatic TGFA was markedly different, showing an increase in palmitic (16:0, P less than 0.01), palmitoleic (16:1, P less than 0.05), and oleic acids (18:1, P less than 0.05) and a decrease in linoleic acid (18:2, P less than 0.001). These changes could not be accounted for by a preferential absorption or mobilization of 16:0, 16:1, and 18:1, or by an increased utilization of 18:2 by the liver. It is proposed that an increased conversion of carbohydrate to fat occurs during the period of rapid weight loss when a relative excess of carbohydrate to amino acids results from an imbalance in the intestinal absorption of carbohydrate and protein.

The inducing effect of feprazone, a pyrazolone anti-inflammatory agent, on hepatic drug-metabolizing enzymes has been studied in healthy volunteers. The ratio of 6 beta-hydroxycortisol (6 beta-OHF) to 17-hydroxycorticosteroids (17-OHCS) in urine, used as an indicator of oxidative drug-metabolizing enzyme activity, was increased up to 1.6-times the original level after 5 days of oral treatment with feprazone 300 mg/day. This indicates that feprazone induces hepatic drug-metabolising enzymes in man as does phenylbutazone.

Organ distribution pattern, hepatic uptake ratio, and blood clearance were examined by giving 99mTc-phytate (99mTc-P) to the normal rats. At the same time, the relation between the severity of hepatic function and blood clearance or hepatic uptake ratio of 99mTc-P was studied by using the rats with acute hepatic dysfunction experimentally induced by carbon tetrachloride (CCl4) administration. Furthermore, a comparative discussion on blood clearance test of 99mTc-P was made with serum transaminase test and with histological test of the liver. It appeared appropriate to administer 99mTc-P at the dose of 500 micrograms/kg in order to obtain an effective blood clearance curve. A major part of 99mTc-P intravenously administered was take up into the liver, while the remainder of small amount into the spleen, kidneys, lung, and so on. Little was recognized in the thyroid gland. The hepatic uptake ratio of 99mTc-P reached the maximum 15 minutes after the administration. The disappearance rate of 99mTc-P from blood decreased with the increase in dose of CCl4 and with the passage of time after the CCl4 administration. The blood clearance test of 99mTc-P showed a sensitive reaction for the acute hepatic dysfunction induced by CCl4 equally to or higher than the serum transaminase test or histological test of the liver.