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)

Rats and hamsters were fed ETU at levels of 0, 5, 17, 60, 200 mg/kg in the diet. Body weights, food consumption, seric enzyme activities (GPT, alkaline phosphatase), hepatic enzyme activities (GPT, alkaline phosphatase G6PDH), cholesterolemia, thyroid weight and others organs, histology were the criteria studied. ETU was found causing hypercholesterolemia for the 2 species at 5 mg/kg dietary levels. Thyroid impairement is predominant in rat and hepatic impairment is predominant in hamster. ETU was found to be not carcinogenic for hamsters even at 200 mg/kg level and carcinogenic for rats at 60 mg/kg level for males and 200 mg/kg level for females.
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PMID:[Difference in the sensitivity of the hamster and the rat to the effects of long-term administration of ethylenethiourea]. 100 99

In risk assessments the various forms of iodine have been treated as if they were toxicologically equivalent. While iodide (I-) and iodate (IO3-) have been studied, no studies concerned with the subchronic toxicity of iodine (I2) have been conducted in experimental animals. This study examined toxicities associated with iodine. Rats were treated with 0, 1, 3, 10, and 100 mg/l of either iodine or iodide (as Nal) in the drinking water for 100 d. Treatment had no effect on body, brain, or heart weights in either sex, or on testes weights in male rats. Although differences in kidney and liver weights were noted, they did not appear to be treatment related. Thyroid weight in male rats was significantly increased with an increasing concentration of iodide in the water, but not iodine. In contrast, thyroid weight decreased at the highest dose of iodide in female rats. Hematocrit, hemoglobin, and blood urea nitrogen (BUN) values were relatively constant and did not vary with treatment. There were no significant differences in AST, ALT, cholesterol, and triglyceride values. After 10 d on treatment a dose-related trend in increased plasma T4 concentrations was observed in both sexes treated with iodine. Statistically significant increases in the T4/T3 ratio in both sexes was also noted with iodine treatment. This increase was maintained for 100 d of treatment. Iodide did not produce this effect at 10 d. Although there was a significant increase in T4/T3 ratios in female rats after 100 d of treatment with iodide, the magnitude of the changes was smaller than that observed with iodine treatments. The results of this study indicate that iodine and iodide affect thyroid hormone status in substantially different ways.
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PMID:Comparison of toxicity induced by iodine and iodide in male and female rats. 198 65

Thyroid function tests were evaluated in 34 patients with acute viral hepatitis (AVH) and in 38 healthy controls (C). As expected, AVH patients displayed a significant increase in T4, rT3 and TBG serum levels with respect to C, while FT4 and TSH concentrations were similar. A positive correlation between TBG and T4 was evident in C, but not in AVH. In this group there was, instead, an inverse correlation between the sum of serum levels of GOT + GPT and T4 concentrations. When AVH patients were divided in "high necrosis" (HN, serum GOT + GPT greater than 2000 UI/l) and "low necrosis" (LN, serum GOT + GPT less than 2000 UI/ml) groups, we found a significant reduction in both T4 and T3 serum concentrations in HN with respect to LN, despite similar levels of TBG, albumin, FT4 and TSH. The hypothesis that thyroid-hormone binding inhibitors (THBI), released during severe liver cell injury, accounted for an impaired serum binding capacity in HN-AVH, was confirmed by the significant increase in FT4/T4 ratio and by the demonstration of THBI activity in pooled sera of these patients, with respect to LN subgroup. Our present finding may clarify the unexplained observation of reduced T4 levels in patients with fulminant hepatitis and the ominous prognostic significance of a "low T4 syndrome" in subjects with severe liver disease and/or other systemic illnesses.
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PMID:Thyroid function tests in acute viral hepatitis: relative reduction in serum thyroxine levels due to T4-TBG binding inhibitors in patients with severe liver cell necrosis. 249 20

A specific radioimmunoassay (RIA) has been developed that has sufficient sensitivity to allow measurement of the changes in plasma and tissue glutathione S-transferase (GST) YaYa concentrations which occur following thyroid hormone administration in the rat. Using the RIA it was demonstrated that the only tissues that had significant amounts of GST YaYa were liver, small gut and kidney. Administration of triiodothyronine (T3) or thyroxine (T4) resulted in increases in plasma GST YaYa concentration and in animals given high doses of T4 plasma alanine aminotransferase activity was also elevated. Thyroid hormone administration produced a significant fall in the hepatic content of GST YaYa and in total GST activity, as assessed using 1-chloro-2,4-dinitrobenzene as substrate. It is concluded that the elevated plasma GST YaYa concentrations observed following administration of thyroid hormones result from hepatic damage, not from induction of hepatic synthesis of the enzyme.
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PMID:Hepatic damage in the rat following administration of thyroxine or triiodothyronine, assessed by measurement of plasma glutathione S-transferase YaYa concentrations. 381 55

Hyperthyroidism was diagnosed in 131 cats during a 3 1/2-year period. The cats ranged in age from 6 to 20 years; there was no breed or sex predilection. The most frequent clinical signs included weight loss, polyphagia, increased activity, polydipsia, polyuria, and vomiting. Common serum biochemical abnormalities included high values for alkaline phosphatase activity (75%), lactate dehydrogenase activity (66%), aspartate transaminase activity (66%), and alanine transaminase activity (54%). Electrocardiographic changes included tachycardia (greater than or equal to 240 beats/min) and increased R-wave amplitude in lead II (greater than or equal to 0.9 mV) in 66% and 29% of the 131 cats, respectively. Thoracic radiography in 82 cats revealed cardiomegaly in 40 (49%) of these cats; 16 cats with congestive heart failure also had pulmonary edema or pleural effusion. In 5 cats with markedly increased fecal volume, mean 48-hour fecal fat content was significantly greater than normal, with daily fat excretion 2 to 15 times the upper limit of normal. Base-line serum thyroxine concentrations were increased above normal range in all cats, whereas triiodothyronine concentrations were increased in 127 (97%) of the 131 cats. In 11 cats tested, mean thyroxine concentration did not increase significantly after thyroid-stimulating hormone administration. Mean 24-hour percentage of thyroid radioiodine uptake in 32 hyperthyroid cats was significantly higher (39.1%) than normal (9.2%). Thyroid scans, performed on 126 cats, showed enlargement and increased radionuclide accumulation in 1 thyroid lobe in 36 (29%) and both lobes in 90 (71%) of the cats.
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PMID:Feline hyperthyroidism: pretreatment clinical and laboratory evaluation of 131 cases. 687 10

Thyroid hormone concentrations and measures reflecting thyroid function were studied in sera from 35 patients receiving long-term phenytoin (PHT) or carbamazepine (CBZ) therapy. The mean concentrations of T4, FT4, FT3, and rT3, but not T3, of these patients were significantly lower than those of 19 controls of similar age and sex distribution. The mean serum thyrotropin (TSH) concentration was slightly but significantly higher in patients than in controls, but the serum TSH response to TRH was not significantly increased. In patients, the higher mean clinical diagnostic index of hypothyroidism (CDI-HT: -20.3 +/- 19.1 vs. -33.7 +/- 8.5, p < 0.05) and higher ratio of preejection period to left ventricular ejection time (PEP/LVET: 0.343 +/- 0.065 vs. 0.334 +/- 0.030, p < 0.05) than in controls were compatible with tissue hypothyroidism. However, comparison of the mean levels of alanine aminotransferase (ALAT), creatine kinase (CK), creatinine, triglycerides, cholesterol, high-density lipoprotein (HDL) cholesterol, osteocalcin, procollagen type III aminoterminal propeptide, and somatomedin-C showed no significant differences between patients and controls. The increased mean angiotensin convertase and sex hormone-binding globulin (SHBG) levels, typical of hyperthyroidism, were probably caused by drug effects. Fourteen patients with a subnormal FT4 concentration in serum participated in a double-blind thyroxine treatment cross-over study. Neither the mean CDI-HT score, nor the systolic time intervals were significantly different between the thyroxine and placebo periods. Five patients benefited subjectively from the treatment. On the basis of all data from the cross-sectional and thyroxine treatment studies, we conclude that patients receiving anticonvulsant drugs chronically are eumetabolic and do not need thyroxine supplementation.
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PMID:Thyroid status of patients receiving long-term anticonvulsant therapy assessed by peripheral parameters: a placebo-controlled thyroxine therapy trial. 758 56

The impact of type 1 diabetes mellitus on liver gamma-glutamyltranspeptidase, a premalignant marker, was studied. Diabetes was induced in male Sprague Dawley and Fischer 344 rats by administration of Streptozotocin, which produced a stable and moderately severe diabetic state. In liver homogenates, gamma-glutamyltranspeptidase was increased over control levels: 1.2, 8.1 and 13.2 fold in Sprague-Dawley rats; 4.8, 58.4 and 84.7 fold in Fischer 344 rats; at 1, 3 and 6 weeks following Streptozotocin treatment. In plasma membranes isolated from the livers of Fischer 344 rats, gamma-glutamyltranspeptidase was increased over control levels: 5.6, 75 and 127 fold at weeks 1, 3 and 6 following Streptozotocin treatment. The relative specific activity of 5'-nucleotidase was found to be similar: 9-14, indicating comparable degrees of plasma membrane purity. Plasma glutamate-pyruvate transaminase levels were minimally and similarly affected at all time points indicating lack of association of increasing gamma-glutamyltranspeptidase activity with overt liver damage. Thyroid hormone replacement, with both T3 (0.6 micrograms/Kg) once a day and T4 (6.0 micrograms/kg) twice a day for three days elicited a further 30% increment in enzyme activity. Insulin replacement (20-40 units/200 g body weight) twice a day for five days reduced enzyme activity 51% at week 6. This was associated with an increase in gamma-glutamyltranspeptidase in the plasma from 14 fold over control levels in the diabetic state at week 6 to 53 fold over control levels after insulin replacement at week 6. It is proposed that the diabetes-induced increase in gamma-glutamyltranspeptidase is reduced by an insulin-directed shedding of the enzyme into the plasma.
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PMID:The impact of type I diabetes on rat liver gamma-glutamyltranspeptidase. 786 3

The antioxidant defense system in liver tissue in experimental hyperthyroidism and/or in iron supplementation was investigated. Thyroid hormones (T3, T4, TSH), ferritin (marker of iron status), antioxidant status components (glutathione [GSH], glutathione peroxidase [GSH-Px], superoxide dismutase [SOD]), and serum transaminases (GOT and GPT, both of which are known to be released from damaged hepatocytes), were measured. Hyperthyroidism in rats, induced by L-thyroxine administration, significantly raised SOD activity (p < 0.05), but significantly decreased GSH-Px activity and GSH values (p < 0.001) in the liver. In the L-thyroxine administered and iron supplemented (TI) group, GSH and GSH-Px values of liver tissues were significantly lower than those of control rats (p < 0.05). GSH-Px levels of the TI group were higher (p < 0.001), and SOD levels significantly lower (p < 0.001) than those of the L-thyroxine administered group. We conclude that hyperthyroidism induces SOD activity in liver; ferritin levels increase in hyperthyroidism, contributing to the antioxidant defense system; GSH-Px and GSH levels are decreased significantly in hyperthyroidism either due to inactivation due to increased oxidative stress or to insufficient synthesis; iron supple- and GPT analysis); iron decreases the effect of T4. This must be taken into consideration during iron supplementation.
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PMID:Evaluation of antioxidant status in liver tissues: effect of iron supplementation in experimental hyperthyroidism. 1063 95

Toxicology studies were conducted by exposing groups of F344/N rats and B6C3F1 mice of each sex to 1,2,4,5-tetrachlorobenzene (greater than 99%percnt; pure) at various concentrations in formulated diets for 14 days or 13 weeks. Dietary concentrations were 0, 30, 100, 300, 1,000, or 3,000 ppm 1,2,4,5-tetrachlorobenzene in the 14 day studies. All rats survived to the end of the studies, but all mice in the 3,000-ppm groups died (five animals per group). Histologically, exposed male rats had an accumulation of abnormal hyaline droplets in the renal cortical epithelium. Significant histologic lesions were not seen in female rats or in mice of either sex. Dietary concentrations were 0, 30, 100, 300, 1,000, or 2,000 ppm 1,2,4,5-tetrachlorobenzene in the 13-week studies (10 animals per group). All rats survived to the end of the studies; two female mice in the 2,000-ppm group were killed in a moribund condition. Body weight gains in the higher dose groups of rats and mice were less than those of controls. In exposed male rats, lesions included renal cortical tubular epithelial hyaline droplet formation, cortical tubular regeneration, and medullary granular casts and mineralization. This spectrum of renal lesions in male rats is consistent with the entity described as "hydrocarbon or hyaline droplet nephropathy." In some exposed female rats (30- to 2,000-ppm groups), there was renal cortical tubular cell regeneration plus accumulation of an unidentified yellow-brown pigment in the renal cortical epithelium. Centrilobular hepatocellular hypertrophy was observed in the livers of exposed male and female rats. In mice, minimal-to-mild centrilobular hepatocellular hypertrophy was present in males in the 1,000 and 2,000-ppm groups and in females in the 2,000-ppm group. Minimal-to-mild individual hepatocyte degeneration occurred in mice of each sex in the 2,000-ppm groups. Increased serum sorbitol dehydrogenase and alanine aminotransferase activity was observed in the two highest dose groups of male and female mice and indicated hepatocellular injury. Thyroid follicular cell hypertrophy was present in male rats in the 300- to 2,000-ppm groups and in female rats in the 100- to 2,000-ppm groups. Decreased free thyroxin and total thyroxin concentrations in male rats in the 300- to 2,000 ppm groups and female rats in the 30- to 2,000-ppm groups indicated a primary hypothyroid state. Hematologic findings for rats that received 1,000 or 2,000 ppm included significantly decreased hematocrit values, hemoglobin concentration, and erythrocyte counts for males and decreased mean cell volume for females; for mice, decreased hemoglobin concentrations, mean corpuscular hemoglobin, hematocrit, and mean cell volume were observed in males in the 2,000-ppm group and in females in the 1,000- and 2,000-ppm groups. These findings suggest a poorly regenerative anemia in both species. The no-observed-effect level (NOEL) for histologic lesions was 30 ppm for male and female rats. The NOEL for histologic lesions in male and female mice was 300 ppm. Synonyms: s-tetrachlorobenzene; benzene tetrachloride. (NOTE: These studies were supported in part by funds from the Comprehensive Environmental Response, Compensation, and Liability Act trust fund (Superfund) by an interagency agreement with the Agency for Toxic Substances and Disease Registry, U.S. Public Health Service.)
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PMID:NTP technical report on the toxicity studies of 1,2,4,5-Tetrachlorobenzene in F344/N Rats and B6C3F1 Mice (Feed Studies) (CAS No. 95-94-3). 1220 61

This study investigated bilirubin levels in 282 1-month-old, healthy, term infants from the Adana region in southern Turkey. Total bilirubin was > 5 mg/dl in 20.2% of the infants and > 10 mg/dl in 6% of the group. Thyroid function and levels of alanine aminotransferase, aspartate aminotransferase and glucose-6-phosphate dehydrogenase were determined in babies with bilirubin levels > 5 mg/dl. The results were normal in all but one case, an infant with a bilirubin level of > 10 mg/dl and glucose-6-phosphate dehydrogenase deficiency. The results indicate that in this population a 5-mg/dl cut-off level for further investigation would mean that 20% of all infants would require further evaluation. This is not cost-effective. Based on our findings, we suggest that the cut-off level for investigating prolonged jaundice in term, 1-month-old, healthy infants in the Turkish population should be > 5 mg/dl.
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PMID:Serum bilirubin levels in 1-month-old, healthy, term infants from southern Turkey. 1236 86


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