[The effect of the distribution of polar groups in a steroid molecule on its inhibition of Na+,K+-ATPase].
Transformed steroids having oxidized side chains in the D ring site and varying by polarity of the substituent at the ring A C(3)-position--acetates, glucosides or with free hydroxyls--in the concentration range 1 X 10(-4) - 1 X 10(-7) M were found to inhibit Na+, K+-ATPase. The extent of inhibition decreases with the rise in the polarity of the A region of the steroid molecule. With the compound devoid of polar groups in the D region an increase in the inhibitory activity is observed on passing from 3-acetate to 3-glucoside. The data obtained confirm the relationship between the extent of Na+, K+-ATPase inhibition and biphilicity of the molecule.
D002301:Cardiac Glycosides / Q000494:pharmacology*; D066298:In Vitro Techniques; D010084:Oxidation-Reduction; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D013256:Steroids / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D002301:Cardiac Glycosides; D013256:Steroids; D000254:Sodium-Potassium-Exchanging ATPase
Vliianie raspredeleniia poliarnykh grupp v molekule steroida na ego ingibiruiushchee deĭstvie na Na+,K+-ATPazu.