Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.99.3 (diaphorase)
 5,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mouse mutation nervous (nr), expressed as a recessive, causes a morphologic change in cerebellar Purkinje cell perikaryonal mitochondria during the 2nd postnatal week which is followed by the selective degeneration of most Purkinje cells. In the present study, mitochondrial dehydrogenase activities (succinic acid dehydrogenase, lactic acid dehydrogenase, malic acid dehydrogenase, reduced diphosphopyridine nucleotide diaphorase and succinic semialdehyde dehyrogenase) are found by light microscopy to be similar in the perikarya of normal and nervous Purkinje cells until after mitochondrial rounding has begun to occur, but then staining increases markedly in nervous. Although only a small fraction of mitochondrial functions were examined, those enzymes assayed were present and competent. In a sense, the only mitochondrial abnormalities demonstrated thus far in nervous Purkinje cells are their unusual shape and probable loss of motility.
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PMID:Histochemical demonstration of mitochondrial dehydrogenases in developing normal and nervous mutant mouse Purkinje cells. 111 28

Human spermatozoa possess a specialized capacity to generate reactive oxygen species (ROS) that is thought to be of significance in the redox regulation of sperm capacitation (De Lamirande and Gagnon, 1993; Aitken et al., 1995). However, the mechanisms by which ROS are generated by these cells are not understood. In this study we have examined the possible significance of NADPH as a substrate for ROS production by human spermatozoa. Addition of NADPH to viable populations of motile spermatozoa induced a sudden dose-dependent increase in the rate of superoxide generation via mechanisms that could not be disrupted by inhibitors of the mitochondrial electron transport chain (antimycin A, rotenone, carbonyl cyanide m-chlorophenylhydrazone [CCCP], and sodium azide), diaphorase (dicoumarol) xanthine oxidase (allopurinol), or lactic acid dehydrogenase (sodium oxamate). However, NADPH-induced ROS generation could be stimulated by permeabilization and was negatively correlated with sperm function. Both NADH and NADPH were active electron donors in this system, while NAD+ and NADP+ exhibited little activity. Stereo-specificity was evident in the response in that only the beta-isomer of NADPH supported superoxide production. The involvement of a flavoprotein in the electron transfer process was indicated by the high sensitivity of the oxidase to inhibition by diphenylene iodonium and quinacrine. These results indicate that NAD(P)H can serve as an electron donor for superoxide generation by human spermatozoa and present a simple strategy for the production of motile populations of free radical generating cells with which to study the significance of these molecules in the control of normal and pathological sperm function.
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PMID:Reactive oxygen species generation by human spermatozoa is induced by exogenous NADPH and inhibited by the flavoprotein inhibitors diphenylene iodonium and quinacrine. 921 32