Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.2 (alanine aminotransferase)
 26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Research on alcohol-induced liver hypoxia in experimental and clinical alcoholic liver disease (ALD) over a span of 20 years is reviewed. The data has repeatedly supported a role for hypoxia in the pathogenesis of ALD but little attention has been given to this phenomenon in a clinical setting where intervention strategies could be developed. Liver hypoxia, particularly when blood alcohol levels are high, has been documented in vivo in rats fed ethanol continuously at a constant rate for prolonged periods. In this model of ALD, the liver pathology, the liver metabolism and the gene expression differ when the livers are compared at the peak and trough blood alcohol levels as monitored daily by measuring the urinary alcohol level cycle (UAL). Genes regulated by the hypoxia-inducible factor (HIF) are expressed more at the peaks, and the livers contain more inflammation at the peaks. However, alanine aminotransferase levels are higher at the troughs suggesting that hypoxia occurs at the peaks and reperfusion injury occurs at the troughs. These findings may be relevant to binge drinking-induced liver injury where hypoxia at high BAL is followed by normoxia and reoxygination injury when BAL falls toward zero.
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PMID:The role of hypoxia in the pathogenesis of alcoholic liver disease. 1516 27

The blood alcohol level cycle (BALC) of the intragastric tube feeding model first described by Tsukamoto et al., has three separate essential mechanistic components. The first is the requirement for an intact functioning thyroid. The evidence for this is that propylthiouracil or severance of the pituitary stalk completely prevents the cycle. What happens instead of the cycle is that the blood alcohol level rises to a lethal level when ethanol is given continuously at a dose of 11 g/kg/day by stomach tube. When excess thyroid hormone is given orally it markedly attenuates the cycle because it interferes with the changes in the level of thyroid hormone during the cycle. The second component is norepinephrine. Catecholamines are markedly elevated at the peaks of the cycle. Both propranolol and phenoxybenzamine, which are beta- and alpha-blockers, prevent the cycle. Also, when catecholamines are fed in excess in the form of ephedrine, the cycle is eliminated. The third element essential to the cycle is the generation of NAD to support the oxidation of alcohol by alcohol dehydrogenase. When complex I (NADH dehydrogenase) of the mitochondrial electron transport chain is inhibited by feeding rotenone, the cycle is totally eliminated and blood alcohol levels remain constant at 200 mg/%. Thus NADH increases and NAD decreases at the peak of the cycle. Without the fluxuation of NAD, ADH activity cannot fluctuate during the cycle and the cycle is prevented. The significance of the BALC in the understanding of alcohol liver disease pathogenesis is that there's a marked difference in the gene expression and liver toxicity when the peaks and troughs of the cycle are compared. The expression of 1000+ genes is either two-fold up or down regulated as determined by microarray analysis. At the peaks there is increased liver pathology, especially inflammatory changes in the liver associated with an increase of iNOS expression. The genes responsive to hypoxia inducible factor 1alpha (HIF1alpha) regulation are increased including the expression of erythropoietin, adrenomedullin and adrenergic receptor alpha 1a and d. The expression of prolyl hydroxylase, which destabilizes HIF1alpha, increases when the BAL drops to low levels during the cycle. The level of oxygen, as measured on the surface of the liver, is decreased at the peaks, compared to control livers. The NADH/NAD ratio is markedly increased and ATP levels are markedly decreased at the BAL peaks. Also, endotoxin in the blood is very high at the peaks and very low at the troughs. When the blood alcohol levels fall during the cycle, there is an increase in ALT, suggesting that reoxygenation from the hypoxic state at the peaks causes an ischemic reperfusion injury-like lesion in the liver. At this time there is also an increase in expression of many important enzymes such as manganese SOD. Genes such as c-fos and CTGF are increased in expression. These contrasting findings at the peaks and troughs indicate that the blood alcohol levels, which fluctuate up and down, change the gene expression and the pathology of the liver.
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PMID:The pathogenesis and significance of the urinary alcohol cycle in rats fed ethanol intragastrically. 1634 1

Sepsis is still a major cause of the high mortality rate in the intensive care unit. Many studies have been published about the severity of sepsis, but the cause of mortality in sepsis and multiorgan failure is still obscure. This study investigated the effects of caffeic acid phenethyl ester (CAPE) particularly on the inflammatory and related histopathological changes in the lung, liver and kidney in an experimental sepsis model. Forty Sprague Dawley rats were used in this study, and were divided into four groups of ten rats each, as follows: Group I was given intraperitoneal saline infusion treatment. Group II was given intraperitoneal CAPE infusion treatment. Sepsis was induced in the animals in Group III (sepsis with saline infusion), while Group IV rats underwent induced sepsis plus CAPE infusion treatment (sepsis with CAPE infusion). Sampling was performed 48 h after treatment. The induction of sepsis resulted in a significant increase in serum glucose, leukocytes, urea, creatinine, LDH levels in BAL, plasma MDA, AST and ALT levels in the sepsis + saline group. The use of CAPE significantly decreased these parameters. Histopathological examination revealed less congestion, portal inflammation, and focal necrosis of the liver, and less congestion, edema, and emphysematous and inflammatory changes in the lung in the sepsis + CAPE group than in the other groups. These results support that CAPE may be used for the treatment of organ failure during sepsis.
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PMID:Effects of caffeic acid phenethyl ester (CAPE) on sepsis in rats. 1860 6

Sarcoidosis is a granulomatous disease of unknown origin, with pulmonary findings in more than 90% of patients. Extrapulmonary involvement is common and all organs can be involved (especially lymph nodes, eyes, joints, central nervous system) but it is rare to find an isolated extrapulmonary disease (less than 10% of patients). Granulomatous inflammation of the spleen and the liver is common in patients with systemic sarcoidosis, while hepatosplenic enlargement is unusual and splenic involvement rare. We report two cases of systemic sarcoidosis, that onset with splenic and hepatosplenic disease, and one case with splenic sarcoidosis without pulmonary involvement. In the first case a 53-year-old woman with mild abdominal pain underwent sonography and CT, which revealed one hypoechoic/hypodense splenic lesion. Laboratory tests were normal. In order to exclude a lymphoma, splenectomy was performed: histology revealed a sarcoid granuloma. After surgery the patient was asymptomatic and now, after two years, disease is silent. The second case is a 66-year-old woman with a recent weight loss (8 kg in two months) and alterated liver function tests (AST 61 U/l, ALT 72 U/l, Alkaline phosphatase 748 U/l, g-GT 381 U/l). Since she had a familiar history of colon cancer, abdominal US scan, abdominal CT scan and MRI were performed and showed inter-aorto-caval lymphadenopathies and discreet multiple bilobar hepatic and splenic substitutive lesions, with no signs of primary tumor. Upper and lower GI endoscopy, full gynecological workup, complete set of tumor markers, bone marrow biopsy were performed. All resulted negative for neoplasia. Small pulmonary infiltrations were observed on chest-CT scan but cytology on BAL was normal. Infections were also excluded. An exploratory laparotomy showed whitish peritoneal, hepatic and splenic nodules. The histological exam revealed chronic granulomatous lesions typical for sarcoidosis. During a two-year follow-up after the splenectomy the patient feels well without any treatment. The third patient is a 32-year-old woman with mild epigastric pain after meals. Neck-thoracic CT, bone scintigraphy and upper GI endoscopy were negative. Abdominal US and MR showed splenomegaly with multiple splenic lesions. Splenectomy was performed and histological exam showed chronic granulomatous lesions typical for sarcoidosis. Further laboratory tests were normal, except for ACE (66 UI/l). After the surgery ACE became normal and now, three years later, the patient is still asymptomatic. We conclude that hepatosplenic involvement is less rare than it is thought. It is often oligosymptomatic or accompanied with unspecific manifestations and laboratory abnormalities. The diagnosis could be difficult; in fact typical laboratory findings of sarcoidosis such as ACE, lysozyme, calcium, were not diagnostic. Ultrasonography and CT were important but the diagnosis was established only with the histological examination of suspected lesions. This latter required to differentiate liver and/or spleen sarcoidosis from tuberculosis and other infections, primary biliary cirrhosis, metastasis or malignant lymphoma.
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PMID:Atypical sarcoidosis: case reports and review of the literature. 2138 7