Enhanced ATPase activity in liver cell nuclei induced by administration of mitomycin C to rats.
Intraperitoneal administration of mitomycin C (40 micrograms/100 g body weight) to male Wistar rats increased the ATPase activity in hypotonic extracts of liver cell nuclei for 4 days after injection. Partially purified ATPase, obtained by the DEAE-cellulose column chromatography of these extracts, showed a 14 times higher specific activity than that found in normal rat liver nuclei. The enzymatic activity was strongly enhanced by the addition of polynucleotides, especially poly A and poly I, to the assay mixture, but was inhibited by GTP, a chelating agent, heparin and thiol-group inhibitors. Quercetin and oligomycin were less effective, and ouabain showed no inhibitory effect. Mg2+ ions were essential, but neither Ca2+, Na+ nor K+ ions were required for the manifestation of the activity. These characteristic properties of the enzyme are similar to those of a nucleoside triphosphatase found in the nuclear matrix and envelope, suggesting that some energy-providing mechanisms involved in the repair processes of DNA damage or cellular injury are induced by mitomycin C administration.
Wakizaka
A
A
Department of Biochemistry, Akita University School of Medicine.
Imai
H
H
Aiba
N
N
Okuhara
E
E
D000244:Adenosine Diphosphate / Q000378:metabolism; D000249:Adenosine Monophosphate / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology*; D004790:Enzyme Induction / Q000187:drug effects; D006868:Hydrolysis; D008099:Liver / Q000201:enzymology*; D008297:Male; D016685:Mitomycin; D008937:Mitomycins / Q000008:administration & dosage / Q000494:pharmacology*; D009711:Nucleotides / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D008937:Mitomycins; D009711:Nucleotides; D000249:Adenosine Monophosphate; D016685:Mitomycin; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases