Inhibitory effect of edaravone on systemic inflammation and local damage in skeletal muscles following long-term ischemia to murine hind limb.

PURPOSE: The purpose of this study was to evaluate local and systemic pathology in a murine model of ischemia-reperfusion (I/R) injury induced by long-term application of a tourniquet on the hind limbs and to assess the protective effects of edaravone, a potent systemic scavenger of free radicals, using this model. METHODS: Sixty C57BL6 mice were divided in two groups, with one group receiving a 3 mg/kg intraperitoneal injection of edaravone and the other group receiving an identical amount of saline 30 min before ischemia under deep anesthesia. The left thigh of each animal was constricted for 4 h with a 4.5-oz. orthodontic rubber band to induce ischemia; 4 h was the critical duration for skeletal muscles. After ischemia, specimens of skeletal muscles, both kidneys, and plasma were collected at 0, 2, 12, 24, 48, and 72 h. Injury to the skeletal muscles and vacuolar degeneration of the kidneys were histologically assessed. Additionally, apoptosis of skeletal muscle cells was assessed by analysis of caspase 3/7 activity and TUNEL staining. Plasma tumor necrosis factor (TNF)-α levels were measured using an enzyme-linked immunosorbent assay kit. RESULTS: Skeletal muscles exhibited prominent injury of myofibers at 12 h after I/R injury, with clear upregulation of plasma TNF-α expression and histologic evidence of tubular dysfunction of the kidneys. Plasma TNF-α levels declined and histologic renal damage was ameliorated in edaravone-treated mice, but treatment did not protect skeletal muscle following ischemia for 4 h. Nonetheless, compared with group S, expression of the apoptosis marker caspase 3/7 was significantly inhibited in the skeletal hind limb muscles of Ed-group mice affected by reperfusion injury following ischemia for 4 h. CONCLUSION: The present study demonstrated that edaravone is a potentially useful drug for systemic or local treatment of reperfusion injury resulting from long-term ischemia.

Pregnant woman with non-comatose autoimmune acute liver failure in the second trimester rescued using medical therapy: A case report.

We present the case of a 25-year-old woman at 16 weeks of gestation who presented with non-comatose autoimmune acute liver failure and was at high risk of developing fulminant hepatitis. Predictive formulas indicated a high probability of developing fulminant hepatitis. Unenhanced computed tomography showed marked hepatic atrophy and broadly heterogeneous hypoattenuating areas. The course of her illness was subacute, and the etiology of liver injury was unclear. Considering all of the above, we predicted a poor prognosis. Plasma exchange (PE) and continuous hemodiafiltration (CHDF) therapy were initiated just after admission. A few days after admission, a high titer (×80) of antinuclear antibody was noted. Because autoimmune hepatitis (AIH) was considered a cause of liver failure, treatment with moderate prednisolone (30 mg/day) doses was administrated, with careful consideration of her pregnancy. Thereafter, her laboratory findings and clinical course gradually improved without the need for liver transplantation. A liver biopsy at 18 days after admission indicated a diagnosis of AIH. She continued the pregnancy and delivered a healthy baby without any complications. Eventually, prednisolone doses were decreased to 10 mg, after which her liver function worsened. The second liver biopsy also indicated a diagnosis of AIH. Accordingly, low-dose prednisolone and azathioprine doses (50 mg/day) were administrated to recover her liver function, after which her liver function regained normalcy. This case illustrates that a pregnant woman with non-comatose autoimmune acute liver failure in the first or second trimester of pregnancy and her fetus can be rescued by PE/CHDF therapy and safe moderate doses of prednisolone.

p53/p66Shc-mediated signaling contributes to the progression of non-alcoholic steatohepatitis in humans and mice.

BACKGROUND & AIMS: The tumor suppressor p53 is a primary sensor of stressful stimuli, controlling a number of biologic processes. The aim of our study was to examine the roles of p53 in non-alcoholic steatohepatitis (NASH). METHODS: Male wild type and p53-deficient mice were fed a methionine- and choline-deficient diet for 8 weeks to induce nutritional steatohepatitis. mRNA expression profiles in normal liver samples and liver samples from patients with non-alcoholic liver disease (NAFLD) were also evaluated. RESULTS: Hepatic p53 and p66Shc signaling was enhanced in the mouse NASH model. p53 deficiency suppressed the enhanced p66Shc signaling, decreased hepatic lipid peroxidation and the number of apoptotic hepatocytes, and ameliorated progression of nutritional steatohepatitis. In primary cultured hepatocytes, transforming growth factor (TGF)-ß treatment increased p53 and p66Shc signaling, leading to exaggerated reactive oxygen species (ROS) accumulation and apoptosis. Deficient p53 signaling inhibited TGF-ß-induced p66Shc signaling, ROS accumulation, and hepatocyte apoptosis. Furthermore, expression levels of p53, p21, and p66Shc were significantly elevated in human NAFLD liver samples, compared with results obtained with normal liver samples. Among NAFLD patients, those with NASH had significantly higher hepatic expression levels of p53, p21, and p66Shc compared with the group with simple steatosis. A significant correlation between expression levels of p53 and p66Shc was observed. CONCLUSIONS: p53 in hepatocytes regulates steatohepatitis progression by controlling p66Shc signaling, ROS levels, and apoptosis, all of which may be regulated by TGF-ß. Moreover, p53/p66Shc signaling in the liver appears to be a promising target for the treatment of NASH.

Serum immunoglobulin a concentration is an independent predictor of liver fibrosis in nonalcoholic steatohepatitis before the cirrhotic stage.

BACKGROUND AND AIMS: The similarity of alcoholic liver disease and nonalcoholic steatohepatitis (NASH) in terms of pathogenic mechanisms suggests that immunoglobulin A (IgA) may play an important role in the pathogenesis of NASH. We aimed to determine whether serum IgA concentrations allow a diagnosis of liver fibrosis in NASH. METHODS: We compared serum IgA concentrations between 108 patients with stages 0-2 NASH and 19 patients with stage 3 NASH. RESULTS: In a univariate analysis, age (P < 0.0001), gender (P = 0.0039), serum albumin level (P = 0.0192), AST (P < 0.0001), AST/ALT ratio (P < 0.0001), platelet count (P = 0.0027), hyaluronic acid level (P < 0.0001), fasting blood sugar (FBS) (P = 0.0013), IRI (P = 0.0001), prothrombin time (%) (P = 0.0287), IgA (P < 0.0001), total sum of IgG, IgA, and IgM (P = 0.0049), and IgA/(IgG + IgA + IgM) (P = 0.0105) were significantly elevated in severe-stage NASH patients compared with the early-stage NASH group. Multiple logistic regression analysis showed that in severe-stage NASH patients, only serum IgA concentrations were significantly elevated (P = 0.0225) relative to early-stage NASH patients. The area under the curve (AUC) of serum IgA concentrations was 0.758 for detecting severe-stage NASH compared with early-stage NASH. CONCLUSIONS: Serum IgA concentration could be a useful independent predictor for assessing the pre-cirrhotic progression of NASH.

Extraskeletal subcutaneous osteosarcoma of the upper arm: A case report.

Extraskeletal osteosarcoma (ESOS) occurs in approximately 1% of soft tissue sarcomas and 2-4% of all osteosarcomas. In particular, subcutaneous osteosarcoma is extremely rare, occurring in less than 10% of ESOS cases. This report presents a case of a subcutaneous tumor in the upper arm of a 79-year-old male. Imaging and pathological findings led to the conclusion that the soft tissue tumor should be diagnosed as subcutaneous osteosarcoma. Additionally, this case report documented the clinicopathological findings of the extraskeletal subcutaneous osteosarcoma in this case and discussed its clinical features by reviewing cases previously described in the literature.

Utility of quantitative 99mTc-phytate scintigraphy to diagnose early-stage non-alcoholic steatohepatitis.

OBJECTIVE: In patients with non-alcoholic fatty liver disease (NAFLD), liver biopsy remains the only reliable method to differentiate simple steatosis from non-alcoholic steatohepatitis (NASH). The objective of this study was to evaluate the efficacy of non-invasive (99m)Tc-phytate scintigraphy in the diagnosis of NASH. MATERIAL AND METHODS: Thirty-seven patients with suspected NAFLD at the time of liver biopsy also underwent (99m)Tc-phytate scintigraphy. Signal intensities of regions of interest (ROI) in the liver, spleen, and heart were measured. We also examined scintigraphic features in a nutritional model of NASH in rats fed a methionine- and choline-deficient (MCD) diet. RESULTS: The liver/spleen uptake ratio determined by scintigraphy was significantly decreased in patients with NASH in comparison with patients with simple steatosis. The liver/spleen ratio was an independent predictor distinguishing NASH from simple steatosis. The decrease was observed for all stages of NASH, including the early stage (stages 1 and 0). In animal studies, the liver/spleen uptake ratio was significantly decreased in rats after 8 weeks of MCD dietary feeding in comparison with control diet-fed rats. CONCLUSIONS: The non-invasive (99m)Tc-phytate scintigraphy test is a reliable tool to differentiate NASH from simple steatosis.

Evaluating the severity of nonalcoholic steatohepatitis with superparamagnetic iron oxide-enhanced magnetic resonance imaging.

PURPOSE: To evaluate the utility of noninvasive assessment of human nonalcoholic fatty liver disease (NAFLD) patients using superparamagnetic iron oxide (SPIO)-enhanced MRI. MATERIALS AND METHODS: Nineteen NAFLD patients underwent SPIO-enhanced MRI. The values of tau, a time constant for an exponential approximation, were calculated using gradient-echo echo-planar imaging, and the values of %T2, a marker of the T2 relaxation effect of SPIO, were calculated using T2-weighted fast spin-echo images. Correlations between these values and the histological NAFLD activity scores were evaluated. The study protocol was approved by our Institutional Review Board and all patients gave informed consent. RESULTS: There was a statistically significant relationship between the NAFLD activity scores and the tau values (r = 0.66, P = 0.002). The %T2 values were also significantly correlated with the NAFLD activity score (r = -0.58, P = 0.009). A cutoff tau value of 42.8 predicted "definitive NASH" (NAFLD activity score >or=5) with a specificity of 66.7% and a sensitivity of 99.9%, whereas a cutoff %T2 value of 32.5 predicted "definitive NASH" with a specificity of 72.7% and a sensitivity of 87.5%. CONCLUSION: Noninvasive SPIO-enhanced MRI may be helpful for identifying NASH patients among patients suspected of having NAFLD.

Hepatic AdipoR2 signaling plays a protective role against progression of nonalcoholic steatohepatitis in mice.

UNLABELLED: It is unclear how hepatic adiponectin resistance and sensitivity mediated by the adiponectin receptor, AdipoR2, contributes to the progression of nonalcoholic steatohepatitis (NASH). The aim of this study was to examine the roles of hepatic AdipoR2 in NASH, using an animal model. We fed C57BL/6 mice a methionine-deficient and choline-deficient (MCD) diet for up to 8 weeks and analyzed changes in liver pathology caused by either an AdipoR2 short hairpin RNA-expressing adenovirus or an AdipoR2-overexpressing adenovirus. Inhibition of hepatic AdipoR2 expression aggravated the pathological state of NASH at all stages: fatty changes, inflammation, and fibrosis. In contrast, enhancement of AdipoR2 expression in the liver improved NASH at every stage, from the early stage to the progression of fibrosis. Inhibition of AdipoR2 signaling in the liver diminished hepatic peroxisome proliferator activated receptor (PPAR)-alpha signaling, with decreased expression of acyl-CoA oxidase (ACO) and catalase, leading to an increase in lipid peroxidation. Hepatic AdipoR2 overexpression had the opposite effect. Reactive oxygen species (ROS) accumulation in liver increases hepatic production of transforming growth factor (TGF)-beta1 at all stages of NASH; adiponectin/AdipoR2 signaling ameliorated TGF-beta-induced ROS accumulation in primary cultured hepatocytes, by enhancing PPAR-alpha activity and catalase expression. CONCLUSION: The adiponectin resistance and sensitivity mediated by AdipoR2 in hepatocytes regulated steatohepatitis progression by changing PPAR-alpha activity and ROS accumulation, a process in which TGF-beta signaling is implicated. Thus, the liver AdipoR2 signaling pathway could be a promising target in treating NASH.

Functional and immunochemical characterization of a novel organic anion transporter Oat8 (Slc22a9) in rat renal collecting duct.

In this study, we demonstrate that a putative membrane unknown solute transporter 1 of the rat kidney (UST1r; Slc22a9) is a multispecific transporter of organic anions (OAs). When expressed in Xenopus oocytes, UST1r mediated uptake of ochratoxin A (OTA; K(m) = 1.0 microM) and sulfate conjugates of steroids, such as estrone-3-sulfate (ES; K(m) = 3.1 microM) and dehydroepiandrosterone sulfate (DHEAS; K(m) = 2.1 microM) in a sodium-independent manner. We herein propose that UST1r be renamed OA transporter 8 (rOat8). rOat8 interacted with chemically heterogenous anionic compounds, such as nonsteroidal anti-inflammatory drugs, diuretics, probenecid, taurocholate, and methotrexate, but not with the organic cation tetraethylammonium. The rOat8-mediated ES transport was: a) cis-inhibited by 4-methylumbelliferyl sulfate and beta-estradiol sulfate, but not by glucuronide conjugates of these compounds, b) cis-inhibited by four- and five- carbon (C4/C5) dicarboxylates (succinate and glutarate (GA)), and c) trans-stimulated by GA, whereas the efflux of GA was significantly trans-stimulated by ES. By RT-PCR, rOat8 mRNA was expressed in proximal convoluted tubules and cortical and outer medullary collecting ducts, whereas in immunochemical studies, Oat8 was identified as the ñ58 kDa protein that in the collecting duct colocalized with the V-ATPase in plasma membranes and intracellular vesicles in various subtypes of intercalated cells. Molecular identification of Oat8 in these cells indicates a possible novel role of OAT family in the renal secretion/reabsorption of OA and acids and bases via affecting the V-ATPase-dependent functions.

[Gamma glutamyl transpeptidase (gammaGTP) in the era of metabolic syndrome].

Current knowledge on gamma glutamyl transpeptidase (gammaGTP) was reviewed. This enzyme, which is mainly expresses on the cell surface, is thought to participate in catalyzing glutathione breakdown, resulting in the formation of cystein, a thiol compound exerting antioxidant effects. The most important role of this enzyme in vivo seems to recover cystein from extracellular glutathione to preserve intracellular homeostasis of oxidative stress. Increase in environmental oxidative stress may induce this enzyme via NFkB. However, its excessive induction may contrary raise oxidative stress and cause subsequent organ injuries since cysteinylglycine, an intermediate of the glutathione breakdown, affects the iron metabolism, resulting in the production of free radicals. Recently, there are multiple lines of evidence that the development of hypertension, hyperlipidemia, diabetes mellitus is associated with increased serum gammaGTP levels. The oxidative stress derived from gammaGTP may participate in the development of these morbid conditions and would account for these associations. However, since subjects associated with excessive drinking and overweight, two major factors increasing serum gammaGTP level are usually suffering from hypertension, hyperlipidemia, diabetes mellitus, it is most likely that the associations are attributed to excessive drinking and overweight. We recently demonstrated that level of serum gammaGTP is inversely associated with that of serum adiponectin, a sort of adipocytokines. In that abnormalities of adipocytokines including adiponectin cause hypertension, hyperlipidemia, diabetes mellitus as well as fatty liver that is associated with increased gammaGTP level, the status of adipocytokines may stand behind the associations among these factors in obese subjects. Moreover, we demonstrated that serum gammaGTP level is inversely associated with subjects' statuses of lifestyles evaluated by Breslow's lifestyle index, suggesting that serum gammaGTP activity could be a tool for screening of subjects with unhealthy lifestyles. In that unhealthy lifestyles cause various morbid conditions designated as lifestyle-related diseases that is thought to comprehend metabolic syndrome and/or alcohol-related diseases, such screening and intervention in their correction should be significant to prevent their development. The consensus currently reached is that increased serum gammaGTP activity is associated with increased mortality. In that excessive drinking, obesity, as well as improper lifestyle elevate serum gammaGTP activity meanwhile cause various morbid conditions that make lifespan shorter, the view is not surprising.

An inverse association between serum gamma glutamyl transpeptidase activity and Breslow's Lifestyle Index; its practical application for screening of subjects with unhealthy lifestyles.

We examined whether serum gammaGTP activity (gammaGTP) is associated with Breslow's lifestyle index and whether it could be used as a tool to detect subjects with unhealthy lifestyles. To that effect, 724 male Japanese workers excluding patients suffering from hepatitis virus infection, autoimmune liver diseases and apparently active bile duct diseases were cross-sectionally examined. gammaGTP was inversely associated with the total score of Breslow's index for all subjects (lambda=30.643) and in subjects aged 40 or more (lambda=37.073). The association was consistent even after adjustments of subjects' ages and levels of triglycerides, total cholesterol and uric acid (p=0.0001). Among the seven lifestyle factors comprising Breslow's index, improper habits of drinking (p<0.0001), smoking (p=0.0204), exercise (p=0.0189) and body weight control (p<0.0001), were associated with increased gammaGTP. Even in a survey in which subjects who had proper habits of drinking and body weight control were selectively examined, improper habits of smoking and exercise still tended to be associated with increased gammaGTP. Receiver operating characteristic curves indicated that gammaGTP was beneficial for detecting subjects who scored two or less on Breslow's index, at least in subjects aged 40 or more. gammaGTP was associated with insulin resistance level estimated by the homeostasis model assessment (p<0.0001), which was inversely associated with Breslow's index (p=0.0040). gammaGTP could be used as an objective substitute of Breslow's index, allowing us to identify subjects with low scores on Breslow's index, at least after sorting subjects properly. Such screening would enable interventions to correct subjects' unhealthy lifestyles, helping to solve lifestyle-related disease issues.

Acetaldehyde inhibits the formation of retinoic acid from retinal in the rat esophagus.

OBJECTIVE: It has already been demonstrated that the rat esophagus produces retinoic acid from retinol. In this study, this process is further characterized and the effect of acetaldehyde examined to elucidate the possible mechanisms behind the epidemiological evidence that the incidence of esophageal cancer is higher in alcoholics. MATERIAL AND METHODS: Rat esophageal samples were incubated with all-trans retinal and newly formed all-trans retinoic acid (ATRA) was quantified using high-performance liquid chromatography (HPLC). Furthermore, beta-nicotinamide adenine dinucleotide (NAD)-dependent acetaldehyde oxidation by the rat esophagus was examined by tracing NAD reduction using a spectrophotometer. RESULTS: Rat esophageal samples produced ATRA from all-trans retinal in a NAD-dependent manner and the potential was significantly attenuated by phenetyl isothiocynate, an ALDH inhibitor, or acetaldehyde depending on the concentration used. Rat esophageal samples also oxidized acetaldehyde of various concentrations NAD dependently. The ATRA formation potential that was temporarily inhibited by acetaldehyde was recovered to the control level by dialysis when the specimen was incubated with up to 50 microM of acetaldehyde. CONCLUSIONS: The rat esophagus produces retinoic acid from retinal. An ALDH isoform(s) is responsible for this process and physiological concentration of acetaldehyde hampers the process, probably in a competitive manner. Since the disturbance of retinoic acid supply has been implicated in carcinogenicity, this finding may, at least in part, explain the high incidence of esophageal cancer in alcoholics, especially in those with inactive ALDH 2 whose blood acetaldehyde levels become higher than those with active ALDH 2.

Relationship between ethanol consumption level and lifestyle status: excessive ethanol consumption can account for the prevalence of lifestyle-related diseases.

BACKGROUND: Diseases caused by unhealthful lifestyles, namely lifestyle-related diseases demands prompt solutions including preventive measures and effective treatment, especially in the developed countries. To that effect, clear understandings of such syndromes are required. Our recent observations have indicated that insulin resistance could, at least in part, account for the pathogenesis of lifestyle-related diseases. The aim of this study was to clarify whether excessive ethanol consumption could also be another cause of such diseases. METHOD: Lifestyle status was assessed based on Breslow's questionnaires of lifestyle index in 519 Japanese males aged 30 to 65 years. Averaged ethanol consumption level was determined by additional questionnaires and insulin resistance level was estimated by homeostasis model assessment. RESULTS: Ethanol consumption level was inversely associated with the total score on Breslow's lifestyle index. Improper drinking manner was associated with improper habit of smoking and proper habit of eating snacks among six lifestyle factors induced in Breslow's index. CONCLUSION: Subjects with more unhealthful lifestyles consumed greater amount of ethanol, suggesting that excessive ethanol consumption could be one of causes of lifestyle-related diseases. In addition to insulin resistance syndrome, alcohol-related diseases should be cared to address the issues of lifestyle-related diseases.

Retinoic acid formation from retinol in the human gastric mucosa: role of class IV alcohol dehydrogenase and its relevance to morphological changes.

Alcohol dehydrogenase (ADH) participates in the formation of retinoic acid from retinol in various organs including the gastric mucosa. However, its clinical significance still remains to be clarified. In this study, we identified the ADH isoforms responsible for the retinoic acid formation among various ADH isoforms and examined associations among the ADH activities, the retinoic acid formation level, and morphological changes in the human gastric mucosa. Human gastric samples were endoscopically obtained from 67 male subjects. Morphological changes were assessed by the Sydney system and activities of class I, III, and IV ADH isoforms were determined in each specimen. In 26 cases, levels of all-trans retinoic acid (ATRA) formation from all-trans retinol were examined. Among activities of the three ADH isoforms, class IV ADH activity was solely associated with the ATRA formation level. This association was found even when subjects' age and Helicobacter pylori infection status were adjusted. As the degrees of inflammation, atrophy, and intestinal metaplasia increased, the class IV ADH activity as well as the potential for the ATRA formation decreased. Class IV ADH is a major enzyme in the retinoic acid supply in the human gastric mucosa, and the reduction of its activity was associated with decreasing retinoic acid supply and progression of inflammation, atrophy, and intestinal metaplasia in the gastric mucosa. In that retinoic acid is a key molecule for maintaining normal morphology, the reduction of class IV ADH activity may be involved in the pathogenesis of these morphological changes in the human gastric mucosa.

Kupffer cell depletion attenuates superoxide anion release into the hepatic sinusoids after lipopolysaccharide treatment.

BACKGROUND AND AIM: The mechanisms involved in the beneficial effect of gadolinium chloride against endotoxin-induced liver damage were studied. METHODS: Superoxide anions released into the hepatic sinusoids were examined in a liver perfusion model using the cytochrome C method. RESULTS: Gadolinium chloride treatment fully depleted ED2-positive cells from the liver and significantly attenuated superoxide anion release after a lipopolysaccharide or tumor necrosis factor-alpha (TNF-alpha) challenge. Moreover, gadolinium chloride treatment resulted in a significant decline in endothelial cell damage in the hepatic sinusoids as assessed by the purine nucleoside phosphorylase/glutamic-pyruvic transaminase ratio in the liver perfusate. Although gadolinium chloride treatment did not affect the level of serum TNF-alpha, it significantly reduced that of interleukin (IL)-8 and neutrophil migration in the hepatic sinusoids after the lipopolysaccharide challenge. CONCLUSION: These data suggest that a reduction of the superoxide anion level in the hepatic sinusoids in acute endotoxemia and subsequent reduction of neutrophil migration into the liver may indicate that gadolinium chloride treatment suppresses the progression of liver damage in acute endotoxemia.

Inverse association between serum adiponectin level and transaminase activities in Japanese male workers.

BACKGROUND/AIMS: Since a novel polypeptide named adiponectin was shown to prevent the development of steatosis and steatohepatitis in animal models, we studied whether it was also possible in a clinical situation. METHODS: Associations between serum adiponectin levels and serum transaminase activities were studied in 791 Japanese males who were not heavy drinkers, and had no autoimmune or HBV- or HCV-induced liver diseases. RESULTS: Various markers of metabolic diseases including levels of body mass index (BMI), serum triglyceride, total cholesterol, and insulin resistance assessed by the homeostasis model were significantly higher in subjects with increased transaminase activities when compared to those with normal activities. Single regression analyses demonstrated that the logarithmic serum adiponectin level was inversely correlated with the levels of logarithmic serum AST (r=-0.229, P<0.0001), ALT (r=-0.305, P<0.0001), and gammaGTP (r=-0.278, P<0.0001). Even in multiple regression analyses in which subjects' age and levels of BMI, serum triglyceride, total cholesterol, and insulin resistance were adjusted, the inverse correlations were significant (P=0.0426, 0.0332, and 0.0011, respectively). CONCLUSIONS: Hypoadiponectinemia may worsen liver diseases associated with metabolic diseases in clinical cases. In addition to aggravation of insulin resistance and hyperlipidemia, some hypoadiponectinemia specific mechanisms may stand behind the association.

Acetaldehyde accumulation suppresses Kupffer cell release of TNF-Alpha and modifies acute hepatic inflammation in rats.

BACKGROUND: Alcohol-related diseases have multiple and varied associations with acetaldehyde, a highly toxic product of ethanol oxidation that accumulates in the absence of active aldehyde dehydrogenase (ALDH). This study was designed to clarify the role of acetaldehyde in liver injury, specifically in vivo and in vitro effects on Kupffer cell release of the inflammatory cytokine tumor necrosis factor-alpha (TNF-Alpha). METHODS: Rats pretreated overnight with the ALDH inhibitor disulfiram (or saline control) were ethanol loaded and challenged with lipopolysaccharide (LPS), and their blood and histological parameters were examined 3 h later. Similarly, isolated rat Kupffer cells were pretreated with disulfiram or cyanamide incubated in ethanol (1 h), then challenged with LPS and evaluated 2 h later for TNF-Alpha and acetaldehyde levels in the culture medium. TNF-Alpha release from Kupffer cells after LPS challenge was also evaluated following incubation in acetaldehyde and acetate for comparison with ethanol loading. RESULTS: Higher blood acetaldehyde concentration following disulfiram pretreatment significantly attenuated acute hepatic inflammation in the ethanol-loaded, LPS-challenged rat (18 +/- 2.9 vs 30 +/- 3.7 polymorphonuclear cells/portal area; P = 0.01). After LPS challenge, ALDH inhibitor pretreatment attenuated Kupffer cell release of TNF-Alpha in the presence of disulfiram at 5063 +/- 151 pg/ml and cyanamide at 4390 +/- 934 pg/ml, versus no inhibitor, 5869 +/- 265 pg/ml ( P < 0.01), but not in the absence of ethanol. Acetaldehyde significantly suppressed Kupffer cell TNF-Alpha release ( P < 0.05), but acetate treatment did not. CONCLUSIONS: Acetaldehyde accumulation suppresses macrophage function, at least suppressing TNF-Alpha release, which plays a role in modifying acute hepatic inflammation in rats.

The existence of an NAD-dependent pathway for retinoic acid formation from vitamin A (retinol) in rat esophagus and its inhibition by ethanol and histamine 2 (H2) receptor antagonists.

BACKGROUND: Retinoic acid is essential for normal cell differentiation and proliferation and disturbance of its metabolism has been implicated in the pathogenesis of various disorders including malignancy. Retinoic acid has been demonstrated to be produced from retinol via a two step oxidation pathway in which alcohol dehydrogenase isozymes have roles. The aim of this study was to know whether the rat esophagus would have the pathway and whether the retinoic acid formation could be disturbed when alcohol dehydrogenase was hampered. MATERIAL/METHODS: Rat esophageal cytosolic fraction, nicotinamide adenine dinucleotide, and all-trans retinol were incubated together and produced all-trans retinoic acid was detected by high performance liquid chromatography method. RESULTS: Remarkable all-trans retinoic acid formation was observed only when nicotinamide adenine dinucleotide was in existence. The all-trans retinoic acid formation was hampered by addition of ethanol, another substrate of alcohol dehydrogenase, and some histamine 2 receptor antagonists, inhibitors of alcohol dehydrogenase. CONCLUSIONS: These results suggest that rat esophagus has an nicotinamide adenine dinucleotide-dependent all-trans retinoic acid formation pathway in which alcohol dehydrogenase is involved. We hypothesize that disturbance of the all-trans retinoic acid formation pathway by ethanol and histamine 2 receptors may cause various esophageal disorders including esophageal cancer seen in alcoholics and subjects taking histamine 2 receptors excessively.

Significant correlation between insulin resistance and serum gamma-glutamyl transpeptidase (gamma-GTP) activity in non-drinkers.

To understand the significance of elevated serum gamma-GTP levels, factors relevant to the serum gamma-GTP level were studied using data of health check-ups for the employees of a Japanese corporation. The gamma-GTP level was positively correlated with levels of various liver function tests including aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Except for them, the gamma-GTP level was positively correlated with levels of insulin resistance, uric acid, total cholesterol, triglyceride, and body mass index. The correlation between the gamma-GTP level and LDL cholesterol was also observed only when subjects who drank more than 5 times a week were selectively studied. When non-drinkers and opportunity drinkers were selectively studied, 63.6% of subjects whose gamma-GTP level was more than 120 IU/liter showed elevated insulin resistance levels. Multiple factors including insulin resistance may affect serum gamma-GTP activity in clinical subjects.