Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In an earlier report from this laboratory, one of the early manifestations of hypervitaminosis A was shown to be a marked stimulation of hepatic gluconeogenesis. In the present study, effects of feeding 30,000 IU of retinyl palmitate to young rats (80-100 g), once daily, for 2 days on the incorporation of 14C-labeled precursors into glucose and glycogen by liver slices, levels of amino acids in blood and tissues, and activities of some important amino acid catabolizing enzymes in the liver were investigated. A stimulation of hepatic gluconeogenesis in hypervitaminosis A was indicated by the increased incorporation of 14C-labeled alanine and bicarbonate into glucose and glycogen by liver slices. Excessive intake of retinol caused a marked increase in the activities of hepatic alanine aminotransferase and ornithine aminotransferase and a decrease in that of tryptophan pyrrolase, without affecting those of tyrosine aminotransferase and serine dehydratase. The ratio of NADH:NAD in the livers of rats fed excess retinol was significantly increased. It is suggested that enhancement of glucoeogenesis in hypervitaminosis A is caused by a stimulation of gluconeogenic activity of the liver.
...
PMID:Early effects of hypervitaminosis A on gluconeogenic activity and amino acid metabolizing enzymes of rat liver. 2 Apr 86

High concentration of inorganic phosphate in the culture medium of Aspergillus fumigatus inhibited ergot alkaloid synthesis. Addition of L-tryptophan but not mevalonate or 5-methyltryptophan to the above culture restored the alkaloid synthesis to the level found in normal cultures. The decrease in alkaloid synthesis in the fungus accompanies an increase in cell mass, cellular protein and sterol content. Aspartate aminotransferase and alanine aminotransferase activities were significantly increased in the high-phosphate culture.
...
PMID:Effect of phosphate on ergot alkaloid synthesis in Aspergillus fumigatus. 33 88

Serial liver enzyme and bilirubin concentrations were measured in 100 patients undergoing total parenteral nutrition. Between the eighth and tenth days, serum glutamic-pyruvic transaminase levels rose to 5.4 times pretotal parenteral nutrition levels; serum glutamic-oxalacetic transaminase, 2.8 times; bilirubin, 2.3 times, and lactic dehydrogenase, 1.5 times. These elevations were transient, lasting four to ten days. Biopsies of the liver taken during maximal elevations demonstrated marked periportal fatty change. A second elevation of serum glutamic-pyruvic transaminase, serum glutamic-oxalacetic transaminase, alkaline phosphatase and lactic dehydrogenase occurred in one-third to one-half of those patients receiving total parenteral nutrition for longer than a 20 day period. These elevations were more prolonged, and no biopsies were taken. Amino acid solutions contain conversion products of tryptophan, an amino acid that is unstable in the presence of the preservative sodium bisulfite which is added to all commercially available protein solutions. Infusion of these products into rats, either alone or as part of total parenteral nutrition solutions, resulted in periportal fatty change of the livers identical to that seen in our patients receiving total parenteral nutrition. A toxic effect of tryptophan conversion products in total parenteral nutrition solutions is proposed.
...
PMID:Serum hepatic enzyme and bilirubin elevations during parenteral nutrition. 40 35

An attempt was made to determine the effect of steroidal contraceptives on the utilization of Vitamins-B1 and B6. Subjects, aged 22-38 years, were not taking any external source of vitamins. A 24-hour urine sample was collected and a fasting blood sample drawn for the estimation of erythrocyte amino-transferases and transketolase. Then each subject was given 2 gm of L-tryptophan. Another 24-hour urine specimen was then collected. Xanthurenic acid values in urine specimens were compared. Ovral or norgestrel was then given for 3 cycles. After these 3 cycles, blood collections and tryptophan load tests were repeated. Erythrocyte alanine aminotransferase (EAIT) and aspartates aminotransferases (EAsT) were measured. Also, erythrocyte transketolase (ETK) was estimated and the "TPP" effect determined by adding 75 mcg of thiamine pyrophosphate. of 11 women taking Ovral, 7 showed an abnormal response to the tryptophan load as shown by the xanthurenic acid excretion. Responses of all 11 women on norgestrel to tryptophan loads were normal. EAIT and EAsT tests were normal with both drugs (p more than .05). Erythrocyte transketolase activity was not significantly changed by either preparation (p more than .05). The increased xanthurenic acid excretion with Ovral after tryptophan load is thought to indicate Vitamin-B6 deficiency. Basal levels of ETK decreased in 7 of 10 women on Ovral but increased in 5 of 8 women on norgestrel therapy. Also, in vitro stimulation with TPP was observed in 4 of these women. The relation of this finding to Vitamin-B1 is not clear. Urinary thiamine, blood pyruvic acid, and alpha-ketoglutaric acid and transketolase activity require study to assess the Vitamin-B1 status under contraceptive therapy.
...
PMID:Short-term effect of ovral and norgestrel on the vitamin B6 and B1 status of women. 119 31

The synthesis and release of alanine and glutamine have been studied in the intact rat epitrochlaris skeletal muscle preparation. Aspartate, cysteine, leucine, valine, methionine, isoleucine, serine, theronine, and glycine increased significantly the formation and release of alanine from muscle. Cysteine, leucine, valine, methionine, isoleucine, tyrosine, lysine, and phenylalanine increased the rate of glutamine synthesis. Only ornithine, arginine, and tryptophan were without effect on the synthesis of either alanine or glutamine. Half-maximal stimulation of alanine and glutamine formation by added amino acids was observed with concentrations ranging between 0.5 and 1.0 mM. Increases in alanine and glutamine formation were not accompanied by changes in pyruvate production or glucose uptake. The progressive decline in alanine and glutamine synthesis noted on prolonged incubation was prevented by the addition of amino acids to the incubation medium. Stimulation of alanine synthesis by added amino acids was unaffected by inhibition of glycolysis with iodoacetate. Inhibition of alanine aminotransferase with aminooxyacetate significantly decreased alanine formation. Pyruvate and ammonium chloride did not increase further the rate of either alanine or glutamine formation above that produced by added amino acids. These data indicate that most amino acids are precursors for alanine and glutamine synthesis in skeletal muscle. A general mechanism is presented for the de novo formation of alanine from amino acids in skeletal muscle, and the importance of proteolysis for the supply of amino acid precursors for alanine and glutamine synthesis is discussed.
...
PMID:Alanine and glutamine synthesis and release from skeletal muscle. II. The precursor role of amino acids in alanine and glutamine synthesis. 124 59

1. Three experiments were conducted to study the effect of dietary L-tryptophan supplementation (250-1000 ppm) on lipid accumulation, an occurrence of hemorrhages and microsomal mixed function oxidase in the liver of laying hens. 2. Dietary L-tryptophan supplementation resulted in significant decreases in hepatic lipids, in particular triglyceride, and occurrence of hemorrhage in laying hens. 3. Hepatic lipid accumulation by estrogen injection in starved-refed growing chicks decreased as dietary tryptophan content increased. 4. Supplementation of L-tryptophan at 1000 mg/kg diet enhanced alanine aminotransferase activity in the hepatic tissue and at 500 mg/kg diet, increased cytochrome b5, a component of the mixed function oxidase, in the hepatic microsomes. 5. These results demonstrate that L-tryptophan alleviates fatty liver in laying hens and modifies microsomal mixed function oxidase in the liver.
...
PMID:L-tryptophan alleviates fatty liver and modifies hepatic microsomal mixed function oxidase in laying hens. 135 43

The present study was designed to examine the effects of methanolic extract (PE-ME), isoflavonoid fraction (PF-IF), triterpenoid saponin fraction (PF-SP) and N-acyl-N1-glucosyl-tryptophan (PF-P) isolated from puerariae flos on alcohol-induced unusual metabolism (as for glucose (BG), triglyceride (TG), and urea nitrogen (BUN) level in blood) and experimental liver injury (model: CCl4- and high fatty food induced) in mice. These alcohol-induced increasing responses were inhibited by the extracted and refined substances from puerariae flos. In short, PF-ME (4500 mg/kg) and PF-P (400 mg/kg) inhibited an increase in BG level induced by alcohol, whereas PF-IF (1000 mg/kg) and PF-SP (1000 mg/kg) did not. Similary, PF-ME and PF-SP inhibited an increase in TG induced by alcohol, whereas PF-IF did not. In addition, PF-IF and PF-SP inhibited increasing BUN level. Still more, PF-IF and PF-SP significantly inhibited an increase in gulutamate oxalacetate transaminase or gulutamate pyruvate transaminase level induced by high-fatty food and CCl4 in control animals. Especially PF-IF (250 mg/kg) administration showed a remarkable effect (inhibition: 76.3%) in control animals. These results suggested that puerariae flos or its combination drugs may be a useful drug as a traditional medicinal system for counteraction to drinking.
...
PMID:[Pharmacological studies on puerariae flos. II. The effects of puerariae flos on alcohol-induced unusual metabolism and experimental liver injury in mice]. 227 52

We compared the vitamin B-6 status of 12-wk-old rats (n = 12) fed excess (1400 mg/kg diet) or the recommended level (7 mg/kg diet, control) of pyridoxine (PN) hydrochloride to test if excess vitamin B-6 would cause tissue depletion of pyridoxal phosphate (PLP), the active coenzyme form of vitamin B-6. Plasma PLP, tryptophan-load test results, food intake, and tissue and body weights were not different at wk 6. Red blood cell endogenous alanine aminotransferase activity and PLP concentration were elevated (P less than 0.01) in rats fed 1400 mg PN.HCl/kg diet. In contrast, PLP concentration in muscle was significantly lower (P = 0.01) in rats fed excess vitamin B-6 (9.7 +/- 0.8 nmol/g, mean +/- SEM) than in controls (14.9 +/- 1.4). PLP concentration in other tissues, including plasma, was not affected. In rats fed excess vitamin B-6, pyridoxal was increased in all tissues examined (P less than 0.05), and total vitamin B-6 was increased in plasma, red blood cells and kidneys (P less than 0.05). Total glycogen phosphorylase (a + b) activity in the gastrocnemius was not affected, but phosphorylase a activity was increased in rats fed excess vitamin B-6 (P = 0.025). Concentrations of dopamine and metabolites in the caudate nucleus of the basal ganglia were not affected. A transient, but significant, elevation in acoustic startle response, a central nervous system reflex, was observed in rats fed excess vitamin B-6. The depletion in muscle PLP could not hae been predicted by either plasma or red blood cell PLP concentration, although the latter did reflect vitamin B-6 intake.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Evaluation of vitamin B-6 status and function of rats fed excess pyridoxine. 268 1

A survey of aminotransferase activities present in a cell-free extract of the anaerobic protozoan, Trichomonas vaginalis was performed. 2-Oxoglutarate, oxaloacetate or phenylpyruvate acted as effective amino acceptors with tyrosine, phenylalanine, tryptophan, leucine, valine, isoleucine, aspartate, alanine, ornithine or lysine. Arginine, serine, glutamine, glycine, beta-alanine and gamma-aminobutyrate were not active as amino donors. With pyruvate as acceptor, significant, yet low, activity was seen only with glutamate, lysine or phenylalanine. Partial purification of enzymes catalysing transamination of leucine, valine, isoleucine, alanine, ornithine and lysine were carried out. A single enzyme catalysed the transamination of ornithine and lysine. The substrate specificity of this enzyme is novel. A separate enzyme catalysed the transamination of all three branched chain amino acids. A third enzyme catalysed the alanine aminotransferase reaction. A fourth enzyme catalysing the transamination both of aromatic amino acids and aspartate has previously been purified [Lowe, P.N. and Rowe, A.F. (1985) Biochem. J. 232, 689-695].
...
PMID:Aminotransferase activities in Trichomonas vaginalis. 309 39

To further evaluate the role of tryptophan and vitamin B6 in bladder carcinogenesis, male Fischer 344 rats were fed 0.2% N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) in semipurified diet or were given semipurified diet alone for 4 weeks. One week later, rats from each group were assigned for the remainder of the experiment to one of four experimental diets, labeled as follows: group 1, control semipurified; group 2, L-tryptophan excess (2%); group 3, vitamin B6-deficient (1.0 mg/kg diet); or group 4, L-tryptophan excess, plus vitamin B6-deficient diet. All surviving rats were killed at 80 weeks of the experiment. Throughout the study, body weights were reduced in the groups fed FANFT and, at 70 and 80 weeks, body weights were reduced in the groups given tryptophan excess. The incidence of urinary bladder carcinoma was highest in the group treated with FANFT, followed by diet with control tryptophan and vitamin B6 levels (40%). The disease incidence was reduced in the vitamin B6-deficient group (13%) and of an intermediate range in the groups fed a tryptophan excess with or without vitamin B6 deficiency (28-29%). Tumors at other sites were greatest in number in FANFT-treated rats fed vitamin B6-deficient diet with excess tryptophan and were significantly fewer in FANFT-treated rats fed vitamin B6-deficient diet alone. Animals given diet deficient in vitamin B6 consistently had depressed levels of alanine aminotransferase activity and plasma pyridoxyl phosphate. FANFT pretreatment decreased alanine aminotransferase activities in rats in some groups and the feeding of tryptophan had variable effects on alanine aminotransferase and plasma pyridoxyl phosphate levels. Urinary tryptophan metabolites were influenced by all treatments, but the results did not correlate with tumor yields. Urinary bladder ornithine decarboxylase activity was not altered in vitamin B6-deficient female rats. These results do not support the hypothesis that increased dietary L-tryptophan promotes bladder carcinogenesis in rats, but other dietary factors might modify the process following FANFT initiation.
...
PMID:Effect of L-tryptophan excess and vitamin B6 deficiency on rat urinary bladder cancer promotion. 381 36


1 2 3 4 5 6 7 Next >>

---