[Synthesis and breakdown of pyridine nucleotide coenzymes in the cell nuclei of guinea pig kidneys in diphtheria intoxication].
The effect of diphteria toxin on the synthesis and degradation of NAD+ and the hydrolysis of NADP+ in the nuclei of guinea pig kidney were studied. Treatment of animals with diphteria toxin (DT) results in considerable reduction of NADpyrophosphorylase activity, which starts 12 hours after incubation and is minimal (50% of that of the control animals) 18 hours after it. During this time interval DT does not affect the activity of NADase and decreases that of NADPase in the nuclei. Thus under diphterial intoxication a decrease of NADPase activity, the synthesis of NAD+ being reduced, probably provides for kidney cells more favourable conditions for maintenance of their synthetic reactions and for restoration of their normal metabolism. It was found that the non-ionic detergent Triton X-100 promotes the NADpyrophosphorylase activity in cell nuclei of intact animals by 40% (on the average) and does not affect the NAD+ synthesis in DT injected animals. Therefore DT not only reduces the nuclear NADpyrophosphorylase activity but also affects the nuclear envelope. The alteration of nuclei under DT treatment is suggested by the decrease of their histone content (30% on the average as compared with the control). The decrease of NADpyrophosphorylase activity under DT intoxication can be considered as an adaptive reaction limiting the availability of NAD+ as the substrate of the EF2 mono (ADP-ribosilation) which results in its unability to promote translation.
D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D004165:Diphtheria / Q000378:metabolism*; D004167:Diphtheria Toxin / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D006168:Guinea Pigs; D006868:Hydrolysis; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D009243:NAD / Q000096:biosynthesis*; D009249:NADP / Q000096:biosynthesis*; D011092:Polyethylene Glycols / Q000494:pharmacology; D013997:Time Factors
D004167:Diphtheria Toxin; D009243:NAD; D011092:Polyethylene Glycols; D009249:NADP
Sintez i raspad piridinnukleotidnykh kofermentov v iadrakh kletok pochek morskoĭ svinki pri difteriĭnoĭ intoksikatsii.