title: [Higher microsomal monooxygenase activity in chloroquine-resistant strains of malarial plasmodium as a possible cause of drug stability].
abstract: Ability to hydroxylate benz(alpha)pyrene--a substrate of arylhydrocarbone hydroxylase (AHH) was distinctly increased in lysates of erythrocytes containing malarial plasmodium. Hydroxylation of benz(alpha)pyrene was inhibited by methyrapone--an inhibitor of microsomal monooxygenases. Activity of AHH was increased from 2- to 3-fold in chloroquine-resistant plasmodium strains as compared with the drug-sensitive strains. Resistance of Plasmodium berghei to chloroquine appears to involve an activation of the monooxygenases system in the parasite.
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism*; D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000378:metabolism; D002738:Chloroquine / Q000633:toxicity*; D004351:Drug Resistance; D004355:Drug Stability; D004789:Enzyme Activation; D007700:Kinetics; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology*; D009153:Mutagens / Q000378:metabolism; D010962:Plasmodium berghei / Q000187:drug effects / Q000201:enzymology*
chemical_list: D001580:Benzopyrenes; D009153:Mutagens; D001564:Benzo(a)pyrene; D002738:Chloroquine; D001189:Aryl Hydrocarbon Hydroxylases
vernacular_title: Povyshennaia aktivnost' mikrosomal'nykh monooksigenaz khlorokhinorezistentnykh shtammov maliariĭnogo plazmodiia kak veroiatnaia prichina lekarstvennoĭ ustoĭchivosti.