Pregnanes that bind to the digitalis receptor.
Steroid binding domains of Na,K-ATPase and the nuclear hormone receptors share amino acid sequence homologies. In a ouabain radioligand assay, the potencies of series of planar or bent steroid moieties suggest that the domain in Na,K-ATPase can accommodate compounds with a planar configuration. The A/B -cis, C/D-cis steroid configuration in the cardenolides, in conjunction with appropriate substituents at the 3 and 17 positions, may represent a fortuitous "fit" for the exogenous compounds. It remains to be determined if the putative physiological digitalis-like substance is a member of a hormonal steroid family, an endogenous ouabain-like compound or both.
Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
F S
FS
LaBella
J F
JF
Templeton
D001665:Binding Sites; D006801:Humans; D010042:Ouabain / Q000378:metabolism; D011278:Pregnanes / Q000737:chemistry / Q000378:metabolism*; D011987:Receptors, Steroid / Q000737:chemistry / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry / Q000378:metabolism*; D013329:Structure-Activity Relationship
D011278:Pregnanes; D011987:Receptors, Steroid; C027082:digitalis receptor; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase