[Effect of transformed steroids on Na,K-dependent ATPase].
The transformed steroids containing delta 5-3 beta-hydroxy- or 3 beta, 5 alpha-dihydroxy-6-keto groups in the A/B rings and an additional cycle E (17,20-dihydroxy-delta-lactone, 16,23-pyranone or delta 20(22)-16 alpha, 17 alpha-dihydroxy-23-carbethoxy-side chain) (1 . 10(-5) M) inhibit Na+,K+-ATPase from pig kidney medulla or from ox brain. The steroid structure has a noticeable effect on ATPase inhibition varying from 3 to 26%. The data obtained suggest that the uneven distribution of polar substituents in the steroid molecule is essential for ATPase inhibition by steroid aglycons.
D000818:Animals; D001921:Brain / Q000201:enzymology; D002417:Cattle; D007679:Kidney Medulla / Q000201:enzymology; D007700:Kinetics; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013256:Steroids / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013552:Swine
D013256:Steroids; D000254:Sodium-Potassium-Exchanging ATPase
Vliianie transformirovannykh steroidov na Na,K-zavisimuiu ATPazy.