Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

DL-alpha-Methyltryptophan (alphaMeTrp), a synthetic analogue of tryptophan, has been found to be a potent inducer of hepatic tyrosine aminotransferase activity in the adrenalectomized rat. alphaMeTrp is inactive in vitro. Unlike the action of other known inducers (tryptophan, hydrocortisone, adenosine cyclic 3:5-monophosphate, and glucagon), maximal stimulation of enzyme activity occurs only 16 to 30 hours after alphaMeTrp administration and the activity is still elevated at 96 hours. Only the L isomer of alphaMeTrp is active, and addition of a hydroxyl group to position 5 of the indole ring renders an inactive compound. The induction can be prevented by actinomycin D or cycloheximide but not galactosamine. Administration of alphaMeTrp together with hydrocortisone produced an additive stimulation of enzyme activity. alphaMeTrp given along with glucagon or adenosine cyclic 3:5-monophosphate caused a further but not additive increase in enzyme activity. Tryptophan given along with alphaMeTrp promoted no extra stimulation whatsoever. These data indicate that alphaMeTrp and tryptophan may act via a common pathway which in part requires RNA synthesis. Other enzymes, namely alanine and aspartate aminotransferase, ornithine aminotransferase, ornithine carbamoyltransferase, serine dehydratase, and histidine ammonialyase, were not affected by treatment of rats with alphaMeTrp.
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PMID:Stimulation of tyrosine aminotransferase activity by dl-alpha-methyltryptophan. 23 76

10 mM D-galactosamine enhibited protein synthesis (1 h incubation time) by 67% in isolated mouse liver cells. Counteracting uridylate deficiency induced by D-galactosamine by preventive administration of 20 mM uridine did not decrease the extent of protein synthesis inhibition. 20 mM D-galactose reverted the inhibition of protein synthesis by D-galactosamine. 10(-5) M epinephrine and 10(-7) M glucagon decreased the incorporation of D-galactosamine into glycogen to 38% and 26% of the control value, respectively, after a 35 min incubation and reduced the inhibition of protein synthesis by D-galactosamine effectively. Experimental evidence supports the view that aminoglycogen formed after D-galactosamine treatment is responsible for the inhibition of protein synthesis.
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PMID:Epinephrine and glucagon counteract inhibition of protein synthesis induced by D-galactosamine in isolated mouse hepatocytes. 47 53

Specific bindings of [3H]prostaglandin E1 ([3H]PGE1), 125I-glucagon and [3H]norepinephrine to D-galactosamine (GalN)-treated rat hepatocytes in primary culture were investigated. After a two hour-treatment with GalN (1 and 10mg/ml), hepatocytes showed an enhanced specific binding to [3H]PGE1, whereas 125I-glucagon binding was little affected and [3H]norepinephrine binding was strongly diminished. Scatchard plot analysis indicated an increase of binding sites of [3H]PGE1. This unusual manner of [3H]PGE1 binding is suggested to indicate a special property of PGE1 receptor and may be associated with the cytoprotective effect of prostaglandins.
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PMID:D-galactosamine-induced cell damage enhances specific binding of prostaglandin E1 to rat hepatocytes. 131 27

Epidermal growth factor (EGF) was purified chromatographically from mice submaxillary glands, and its activity and electrophoretic pureness were identified. The effect of EGF, glucagon-insulin (G-Ins) and EGF-glucagon-insulin mixture(EGF-G-Ins) on stimulation of DNA synthesis in primary cultures of rat hepatocytes and their protective effect on mice with liver injury were investigated. The results showed that G-Ins had significant effect on DNA synthesis in primary hepatocyte culture; EGF showed more significant effect compared with G-Ins; and EGF-G-Ins had the best effect. EGF-G-Ins could increase the survival rate and improve the repair of injured hepatocytes in mice treated with D-galactosamine. Although EGF and G-Ins could reduce the degree of hepatic injury, they did not elevate the survival rate. The present study provided some information on clinical therapy with EGF-G-Ins in patients with fulminant hepatic failure.
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PMID:[Epidermal growth factor for enhancing DNA synthesis of hepatocytes and its protecting effect on animals with liver injury]. 133 7

A hepatic stimulator substance (HSS) was extracted from the liver of male weanling SD rats according to the method of LaBrecque. The mice were injected with carbon tetrachloride or D-galactosamine to induce hepatic injuries and the protective effect of HSS on thus induced hepatic damage was investigated. The results were as follows: (1) HSS could suppresses the elevation of sGPT and sGOT induced by carbon tetrachloride intoxication in a dose-dependent manner. (2) Hepatic histological findings indicated that the degree of CCl4 or D-galactosamine-induced hepatic lesions could be lessened by HSS. (3) CCl4-induced reduction of hepatic mitochondrial succinic dehydrogenase activity could be restored by HSS. (4) Insulin-glucagon enhanced the survival of D-galactosamine intoxicated mice and stimulated hepatocyte proliferation, thus showing less pronounced hepatic damage.
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PMID:[Protective effect of hepatic stimulator substance against experimental acute liver failure in mice]. 179 5

We studied the effect of putrescine on acute liver failure caused in rats by two injections of 1 gm/kg D-galactosamine. The hepatic polyamine level rose only slightly in the D-galactosamine-injected rats treated with glucagon and insulin, and [3H]thymidine incorporation into DNA increased little; these hormones did not improve the survival rate. When D-galactosamine-injected rats were given putrescine, the putrescine concentration in the liver increased and the survival rate of the rats was significantly higher than that of control rats given only D-galactosamine. Putrescine administration tended to lower the serum level of alanine aminotransferase in rats injected with D-galactosamine, so the polyamine might have a protective effect on hepatocytes. Putrescine significantly increased [3H]thymidine incorporation in the liver; thus it accelerated liver regeneration. Difluoromethylornithine decreased the level of putrescine in the liver, decreasing both [3H]thymidine uptake and the survival rate. In the rats treated with D-galactosamine, in which liver damage was so severe that treatment with glucagon and insulin was ineffective, the intraperitoneal administration of putrescine increased the survival rate in acute liver failure. This probably resulted mainly from activation of liver regeneration and possibly from a protective effect of putrescine on the liver.
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PMID:Effects of putrescine on D-galactosamine-induced acute liver failure in rats. 239 Oct 73

Acute fulminant hepatitis was induced in 55 healthy adult male rabbits with the potent hepatotoxin galactosamine hydrochloride (3.75 mmoles per kg i.v.). Control rabbits (n = 27) were divided into three groups: Group I (n = 10) underwent sham surgery for placement of an indwelling central venous catheter; Group II (n = 9) received 5% dextrose and water via an indwelling central venous catheter, and Group III (n = 8) received daily intramuscular injections of 0.9% sodium chloride. Treated rabbits (n = 28) also consisted of three groups: Group IV (n = 9) received 12-hr intravenous infusions of insulin (0.029 units per kg per hr) and glucagon (2.86 micrograms per kg per hr) daily; Group V (n = 10) received a continuous infusion of parenteral amino acids (Travasol), and Group VI (n = 9) received daily intramuscular methylprednisolone (0.69 mg per kg). In each case, treatment was initiated 16 hr following galactosamine injection. Serum aminotransferase activity was determined on Days 0, 1, 4 and 10 of the 10-day study. Liver histology was obtained immediately after death and graded under code on a scale of 1 to 4 for severity of hepatitis. Rabbits surviving 10 days were sacrificed on Day 10 for histologic examination. The extent of galactosamine-induced hepatic injury was similar in all six groups as manifest by peak mean SGPT (range: 2,662 to 3,568 IU per liter), SGOT (range: 4,435 to 5,625 IU per liter) levels and hepatic histologic findings. The overall survival rate in controls was 6/27 (22%); in insulin/glucagon-treated animals 2/9 (22%), and in the amino acid-treated group 2/10 (20%).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A comparative study of the effects of insulin/glucagon infusions, parenteral amino acids and high dose corticosteroids on survival in a rabbit model of acute fulminant hepatitis. 351 Sep 52

Cathepsins M and B from rabbit liver lysosomes were separated by chromatography on Ultrogel AcA34 at low ionic strength and purified to homogeneity, and their catalytic and molecular properties were compared. Cathepsin M was relatively inactive with synthetic peptide substrates. Thus, it hydrolyzed benzoyl arginine naphthylamide at only one-fifth the rate observed with cathepsin B, and no activity was detected with Gly-Phe naphthylamide which is a relatively good substrate for cathepsin B. On the other hand, cathepsin M exhibited a preference for protein substrates. It was more active than cathepsin B in catalyzing the inactivation of the following enzymes: rabbit muscle or liver fructose-1,6-bisphosphate aldolases, rabbit liver fructose-1,6-bisphosphatase and pyruvate kinase, yeast glucose-6-phosphate dehydrogenase, and rabbit muscle glyceraldehyde-3-phosphate dehydrogenase. With glucagon as substrate, both enzymes showed similar peptidyl dipeptidase activities with some minor differences in peptide bond specificity. Cathepsins M and B are similar in size, with apparent molecular weights of 30,200 for cathepsin M and 28,800 for cathepsin B, and in amino acid composition and carbohydrate content. Each contains approximately 2-3 equivalents/mol glucosamine, 3 equivalents/mol mannose, and no fucose or galactosamine. They also show similar microheterogeneity in sodium dodecylsulfate-gel electrophoresis and isoelectric focusing; this microheterogeneity is probably related to differences in glycosylation. Extensive homology in primary structure for the two proteins was indicated by the similar patterns of peptides formed on digestion with trypsin.
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PMID:Purification and properties of rabbit liver cathepsin M and cathepsin B. 406 7

The inhibition of RNA synthesis of isolated mouse liver parenchymal cells caused by 10 mM D-galactosamine was reversible, while the inhibition of protein synthesis remained unaltered after the removal of galactosamine. 10(-5)M epinephrine and 10(07)M glucagon have been shown to decrease aminoglycogen formation and thus to reduce the inhibitory effect of galactosamine on protein synthesis (II). However, these hormones did not decrease the inhibition of RNA synthesis. 10 mM D-galactosamine did not effect the nucleoside and amino acid incorporation of isolated non-parenchymal mouse liver cells. The predominant role of aminoglycogen in the inhibition of protein synthesis in galactosamine induced liver injury is discussed.
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PMID:Reversible inhibition of RNA synthesis and irreversible inhibition of protein synthesis by D-galactosamine in isolated mouse hepatocytes. 618 Feb 92

The authors reported previously that single cell suspensions of syngeneic, allogeneic and xenogeneic hepatocytes can significantly improve survival in a rat model of acute hepatic failure induced by D-galactosamine. This report explores the mechanism by which hepatocyte transplantation reverses the toxin-induced hepatic necrosis. Radioautographic studies indicated that intraperitoneally administered hepatocytes labelled with tritiated thymidine did not repopulate the injured recipient liver. Hepatocytes irradiated with 10 000 rad (i.e., the cells were nonreplicating) also resulted in a significant (P less than 0.001) increase in animal survival when given to rats treated with D-galactosamine. Experiments with subcellular fractions of hepatocytes demonstrated that an intact cell was not required and that a heat stable "factor" (or factors) present in the cytosol fraction, which is not insulin or glucagon, is responsible for the increase in survival observed. This factor appears to increase the rate of endogenous regeneration of the injured recipient liver.
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PMID:Studies into the mechanism of reversal of experimental acute hepatic failure by hepatocyte transplantation. 1. 700 72


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