Oxidative stress during cardiac arrest may inactivate myocardial enzymes and thereby exacerbate ischemic derangements of myocardial metabolism. This study examined the impact of cardiac arrest on left ventricular enzymes. Beagles were subjected to 5 min of cardiac arrest and 5 min of open-chest cardiac compressions (OCCC) before epicardial direct current countershocks were applied to restore si...

seizure is a rare presentation for acute hemolysis due to g6pd deficiency. we report a previously healthy boy who presented initially with seizure and cyanosis and subsequently acute hemolysis, due to glucose-6-phosphate dehydrogenase deficiency (g6pd) and probably secondary methemoglobinemia, following the ingestion of fava beans.

S-(+)-3,4-Dihydroxybutylphosphonic acid, an isosteric analogue of sn-glycerol 3-phosphate, was synthesized stereospecifically and shown to be an effective substrate for rabbit muscle glycerol 3-phosphate dehydrogenase (sn-glycerol 3-phosphate-NAD(+) oxidoreductase, EC 1.1.1.8). Non-isosteric phosphonate analogues of sn-glycerol 3-phosphate showed neither substrate nor inhibitory activity with t...

Glucose-6-phosphate dehydrogenase from intact pea chloroplasts is partially membrane bound and inactivated upon illumination. The inhibitory effect of light can be abolished by addition of methylviologen. Kinetic experiments with glucose-6-phosphate dehydrogenase reveal that, in the dark, the enzyme activity is strongly inhibited by the accumulation of NADPH. The inhibition of NADPH can be reve...

Glyceraldehyde-3-phosphate dehydrogenase is a glycolytic enzyme that catalyses conversion of glyceraldehyde-3-phosphate to 1,3-diphosphoglycerate. ATP has been found to have an inhibitory effect on this enzyme. To establish the interaction between the enzyme and ATP, a fluorescence technique was used. Fluorescence quenching in the presence of ATP suggests cooperative binding of ATP to the enzym...

6,7 -Dideoxy-alpha-D-gluco-heptose 7-phosphonic acid, the isosteric phosphonate analogue of glucose 6-phosphate, was synthesized in six steps from the readily available precursor benzyl 4,6-O-benzylidene-alpha-D-glucopyranoside. The analogue is a substrate for yeast glucose 6-phosphate dehydrogenase, showing Michaelis-Menten kinetics at pH7.5 and 8.0. At both pH values the Km values of the anal...

n-Mannitol has been used as a carbon source for the growth of many microorganisms. Some bacteria contain diphosphopyridine nucleotide-dependent dehydrogenases that will oxidize n-mannitol to n-fructose at the nonphosphorylated level (2-5). On the other hand, Wolff and Kaplan (6, 7) have reported the presence of a diphosphopyridine nucleotide-dependent n-mannitol l-phosphate dehydrogenase that o...

A rise in extracellular D-glucose concentration causes in pancreatic islets a preferential stimulation of aerobic, relative to total, glycolysis. The possible participation in such a phenomenon of a glucose-induced and Ca(2+)-dependent activation of FAD-glycerophosphate dehydrogenase was investigated. In islet homogenates, the activity of the mitochondrial and Ca(2+)-responsive FAD-glycerophosp...