Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.4.1.2 (glutamate dehydrogenase)
 4,380 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mammalian and avian muscles were examined histochemically and biochemically to determine the relative contribution of membrane bound (mitochondrial and sarcotubular) ATPases under the same conditions employed for myofibrillar ATPase. For histochemically investigated Ca+(+)-ATPase activity following incubation at pH 9.4 according to the calcium-citro-phosphate technique, avian muscle displayed distinct mitochondrial localization in both dark and light staining fibres. However, mitochondrial localization did not occur in mammalian muscle fibres. Pretreatment of unfixed frozen sections with ouabain, cyanide and acetone did not prevent the reticular distribution in avian muscle fibres. The present study demonstrates that "myofibrillar" localization is achieved by the Ca+(+)-precipitation technique: provided frozen sections are pretreated with cold acetone, fixed in a fixative containing oligomycin or azide and then incubated in a medium containing glycine-NaO H as buffer. Mitochondria prepared by successive mechanical homogenization or by Nagarse treatment plus 2 min homogenization develop different ATPase activities at pH 9.4 7.4 6.0 and 4.35 as well as stimulation by 70 mM Ca++ at these pHs compared to those ATPase activities in the homogenate of mixed hamster hind leg muscles. Glycerol-3-phosphate dehydrogenase and creatine kinase (both located at the outer surface of the inner mitochondrial membrane) and succinate dehydrogenase and glutamate dehydrogenase (localized at the inner mitochondrial membrane and in the matrix resp.) also show different activities in both mitochondria preparations indicating different membrane properties of both mitochondria. Evidence is obtained that using the calcium-citro-phosphate technique at pH 9.4 oligomycin-sensitive and -insensitive ATPases are activated by Ca++ in both mitochondria preparations. Since in muscle homogenate less than 10% of Ca+(+)-stimulated ATPase activity is oligomycin-sensitive, mitochondrial ATPase exhibit only a small portion of total ATPase from mixed hamster hind leg muscles.
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PMID:Histochemical and biochemical investigations of adenosine triphosphatase in vertebrate mixed muscles. 4 33

This study aimed to compare the metabolic and secretory responses of pancreatic islets from animals with non-insulin-dependent diabetes to D-glucose with the effects of the methyl esters of succinic acid (SME) and glutamic acid (GME). The insulin secretory response to D-glucose was impaired in islets from rats with diabetes which was either inherited (Goto-Kakizaki (GK) rats) or acquired (streptozotocin-treated (STZ) rats). This coincided with a preferential alteration of oxidative relative to total glycolysis in intact islets and a selective defect of FAD-linked mitochondrial glycerophosphate dehydrogenase (m-GDH) in islet homogenates. This enzymatic defect was also found in purified B cells from STZ rats. It contrasted both with unaltered activities of glutamate dehydrogenase and succinate dehydrogenase in the islets of diabetic animals and with a normal or even increased activity of m-GDH in the livers of GK and STZ rats. The oxidation of [1,4-14C]SME and [U-14C]GME appeared decreased in islets of GK or STZ animals when compared with control rats, but no significant difference between control and diabetic rats was observed when the oxidative data were expressed relative to the rate of [U-14C]GME hydrolysis. Nevertheless, the absolute values for insulin release evoked by a non-metabolized analogue of L-leucine (BCH), by SME and by the association of BCH with either SME or GME were invariably lower in islets of GK and STZ rats than in those of control animals.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pancreatic islet response to dicarboxylic acid esters in rats with type 2 diabetes: enzymatic, metabolic and secretory aspects. 784 32