[Molecular polarity dependence of the transformed steroid effect on Na,K-ATPase].
The transformed steroids containing an additional cycle E (delta-lactone or 16.23-pyranone) or 23-carbethoxy side chain (1.10(-5) M) inhibit Na,K-ATPase from pig kidney medulla. The steroid structure has a noticeable effect on ATPase inhibiton varying from 9 to 35%. The data obtained suggest that the position, stereochemistry and the uneven distribution of polar substituents in the steroid molecule are essential for ATPase inhibition by steroid aglycons.
D000818:Animals; D007679:Kidney Medulla / Q000201:enzymology; D008861:Microsomes / Q000201:enzymology; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D013256:Steroids / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013552:Swine
D013256:Steroids; D000254:Sodium-Potassium-Exchanging ATPase
Zavisimost' vliianiia transformirovannykh steroidov na Na,K-ATPazy ot bifil'nosti ikh molekul.