Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was designed to clarify the cardioprotective effects of various class I antiarrhythmic drugs, i.e., aprindine, disopyramide, flecainide, lidocaine, mexiletine, pentisomide and propafenone, on the ischemic heart. Sixty-one adult mongrel dogs were classified into eight groups according to premedication: 1) control group, physiologic saline solution was administered intravenously 25 min before left anterior descending coronary artery ligation; 2) aprindine group, 3 mg/kg body weight of aprindine intravenously; 3) disopyramide group, 2 mg/kg of disopyramide intravenously; 4) flecainide group, 2 mg/kg of flecainide intravenously followed by drip infusion of 100 micrograms/kg per min; 5) lidocaine group, 2 mg/kg of lidocaine intravenously followed by drip infusion of 100 micrograms/kg per min; 6) mexiletine group, 3 mg/kg per min of mexiletine intravenously followed by drip infusion of 15 micrograms/kg per min; 7) pentisomide group, 5 mg/kg intravenously; and 8) propafenone group, 2 mg/kg intravenously. Arterial blood pressure and electrocardiogram were monitored throughout the experiment. Two hours after coronary occlusion, the heart was excised. Myocardial mitochondria were prepared and mitochondrial function (the respiratory control index and the rate of oxygen consumption in state III) was measured polarographically. Fractionation of myocardial tissues was performed and the lysosomal enzyme (N-acetyl-beta-glucosaminidase and beta-glucuronidase) activities among fractions were measured. No significant hemodynamic changes were observed compared with the control group except for those in the disopyramide and flecainide groups; that is, decrease in heart rate without changes in blood pressure compared with the control group was observed. All antiarrhythmic drugs effectively prevented the development of ventricular arrhythmias associated with ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
J Am Coll Cardiol 1989 Jul
PMID:Cardioprotective effects of various class I antiarrhythmic drugs in canine hearts. 273 64

We studied the effects of running-training, heavy exercise and termination of training on the heart weight, the ratio heart to body weight and the cardiac muscle activities of actomyosin ATPase, citrate synthase, succinate dehydrogenase, cytochrome c oxidase, malate dehydrogenase, adenylate kinase and beta-glucuronidase with adult male NMRI-mice. Stable hypertrophy (6-7%), estimated by the ratio heart or ventricle weight to body weight, was achieved by 28 exercises and it was dependent on the running speed (20 vs. 25 m X min-1). The withdrawal of training for 5-61 days did not permanently decrease the heart weight or the heart to body weight ratio to the level of sedentary controls. The activity of enzymes of energy metabolism or actomyosin ATPase were not affected by training, heavy exercise or terminated training. beta-glucuronidase activity slightly (20-25%) increased in the trained animals and remained at a higher level during the period of terminated training. The results suggest that the capacity for aerobic metabolism of normal mice heart is sufficient to meet the enhanced demand for ATP imposed by running-training and that the heart enlargement occurs in equal proportions with the enzymatic potential of the cardiac tissue.
Basic Res Cardiol
PMID:Selected enzyme activities in mouse cardiac muscle during training and terminated training. 623 64

The surviving myocardium of the cat was studied 7 days and 6 weeks following experimental infarction. Seven days after infarction, ultrastructural alterations of the mitochondria indicative of slight hypoxic injury--clearing of the matrix and loss of dense matrix granules--were found. Together with intracellular edema and glycogen depletion this result was considered as a sign of relative hypoxia in the surviving myocardium 7 days after infarction. At the same time beta-glucuronidase activity of tissue homogenates was found to be elevated. Focal ischemic lesions in remote myocardium which have been described by other authors (5, 6, 23) were not detected in our experiments. Six weeks after infarction, the fractional volume occupied by myofibrils had increased whereas the fractional volume of mitochondria had remained unchanged (left ventricle) resp. had decreased (right ventricle). There were no qualitative changes detectable at the ultrastructural level. Based on the morphometric investigation of Anversa (1, 2), our results were regarded indicative of mild compensatory hypertrophy of the surviving myocardium. Glutamate dehydrogenase activity of tissue homogenates was shown to be increased when compared to control values. Furthermore our morphometric results showed that the unit mass of mitochondria has to render an enhanced amount of energy six weeks after infarction which might leave the surviving myocardium with a higher susceptibility to future hypoxic injury.
Basic Res Cardiol
PMID:Morphology and mitochondrial function of the surviving myocardium following myocardial infarction in the cat. 662 21

Elucidation of the mechanism enabling tumor selective PMT in vivo with appropriate glucuronyl-spacer-doxorubicin prodrugs, such as HMR 1826, is important for the design of clinical studies, as well as for the development of more selective drugs. Enzyme histochemistry, immunohistochemistry, and the terminal deoxytransferase technique were applied using human cryopreserved cancer tissues, normal human, monkey, and mouse tissues, and human tumor xenografts to examine mechanisms underlying the selectivity of successful PMT with HMR 1826. It could unambiguously be shown by enzyme histochemistry that necrotic areas in human cancers are the sites in which lysosomal beta-glucuronidase is liberated extracellularly in high local concentrations. The cells responsible for the liberation of the enzyme are mainly acute and chronic inflammatory cells, as shown by IHC. Furthermore, it could be demonstrated that beta-glucuronidase liberated in necrotic areas of tumors can activate HMR 1826, resulting in increased doxorubicin deposition in human tumor xenografts or in human lung cancers subjected to extracorporal perfusion, compared to chemotherapy with doxorubicin. Additionally, the doxorubicin load to normal tissues was significantly reduced compared to chemotherapy with doxorubicin. Surprisingly, the increased doxorubicin deposition in tumors also resulted in strong antitumor effects also in cancers resistant to maximum tolerated doses of systemic doxorubicin. Finally, toxicity studies in mice and monkeys revealed an excellent tolerability of HMR 1826, up to a dose of 3 g/m2 (monkeys). These data suggest that HMR 1826 is a promising candidate for clinical development.
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PMID:Elucidation of the mechanism enabling tumor selective prodrug monotherapy. 951 5

A new glucuronylated prodrug of doxorubicin, potentially useful for ADEPT or PMT cancer chemotherapy, has been prepared from 4-methyl phenyl malonaldehyde. The enol ether spacer, linked via a carbamate to the 3'-amino group of doxorubicin is rapidly cleaved after beta-glucuronidase (E coli) catalyzed hydrolysis at pH 7.2 and 37 degrees C.
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PMID:A new spacer group derived from arylmalonaldehydes for glucuronylated prodrugs. 987 77

The beta-O-glucuronide and beta-O-galactoside of SAHA have been prepared and evaluated as prodrugs for selective cancer chemotherapy (ADEPT, PMT). These new compounds are stable under physiological conditions and do not exhibit any antiproliferative activity compared to the parent drug after a 48-h treatment of H661 cells. The glucuronide derivative did not lead to the release of the drug in the presence of either Escherichia coli or bovine liver beta-glucuronidase. On the other hand, under enzymatic cleavage of galactoside prodrug by the corresponding enzyme, a rapid release of SAHA was observed demonstrating that the beta-O-galactoside of SAHA is a promising candidate for in vivo investigations.
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PMID:Synthesis and biological evaluation of the suberoylanilide hydroxamic acid (SAHA) beta-glucuronide and beta-galactoside for application in selective prodrug chemotherapy. 1715 9

Pyrrolo[2,1-c][1,4]benzodiazepine-beta-glucuronide prodrugs 15a-b, with a potential for selective therapy of solid tumors by PMT and ADEPT have been designed, synthesized and evaluated for selective cytotoxicity in the presence of the enzyme beta-glucuronidase. The prodrugs have been found to possess reduced cytotoxicity compared to the parent moieties, and are excellent substrates for the enzyme, exhibiting cytotoxicity selectively in the presence of the enzyme. Enhanced water solubility and improved stability are the other important outcomes upon modifying these molecules as their prodrugs.
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PMID:Pyrrolo[2,1-c][1,4]benzodiazepine-beta-glucuronide prodrugs with a potential for selective therapy of solid tumors by PMT and ADEPT strategies. 1853 66