title: [Inhibition by ellipticine derivatives of the reactions catalysed by the topoisomerases: preferential inhibition of topoisomerase II].
abstract: We have studied inhibitory effects of ellipticine derivatives on the topoisomerisation reactions by Rat liver enzymes. We used the reactions of relaxation of supercoiled DNA, catalysed by topoisomerase I without ATP and by topoisomerase II with ATP, and also the reaction of decatenation of DNA networks by topoisomerase II. When studying intercalating agents--as elliptieine derivatives are--a problem arose. To distinguish relaxed DNA from native DNA we run our samples in electrophoretic gels containing an intercalating agent: chloroquine. Topoisomerase II, which was inhibited at concentrations about 10(-6) M, was more sensitive than topoisomerase I.
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D004587:Electrophoresis, Agar Gel; D004611:Ellipticines / Q000494:pharmacology*; D066298:In Vitro Techniques; D008099:Liver / Q000201:enzymology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D059004:Topoisomerase I Inhibitors; D059005:Topoisomerase II Inhibitors
chemical_list: D000470:Alkaloids; D004611:Ellipticines; D059004:Topoisomerase I Inhibitors; D059005:Topoisomerase II Inhibitors
vernacular_title: Inhibition par les dérivés de l'ellipticine des réactions catalysées par les topoisomérases: inhibition préférentielle d'une topoisomérase II.