[Mammalian lignans: possible involvement in endogenous digitalis activity].
Lignans are natural products, some of which were recently discovered in animal urines, semen and blood plasma. We investigated the actions of animal lignans obtained by total synthesis or extracted from urines of pregnant women on Na+, K+-ATPase in human red cells and human and guinea-pig heart cell membranes. Some of the tested lignans (enterolactone, prestegane B and 3-O-methyl enterolactone) inhibited Na+, K+-pump activity in human red cells with IC50 ranging from 5 to 9 X 10(-4) M. The IC50 for ouabain (7 X 10(-7) M) was not modified by addition of lignans. Enterolactone inhibited Na+, K+-ATPase activity in human and guinea pig heart membranes. It also displaced [3H]-ouabain binding from human heart with IC50 = 1.5 X 10(-4) M. The apparent dissociation rate constants (kd) of [3H]-ouabain were not different in presence of digoxin or enterolactone. Enterolactone exhibited a poor cross reactivity against antidigoxin antibodies. The aglycones of the lignans studied here were slight inhibitors of the Na+, K+-ATPase. However, we cannot exclude that a glycosyl- (and/or butenolide-) derivative of enterolactone could be one "endogenous ouabain-like" factor.
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D007700:Kinetics; D017705:Lignans; D009206:Myocardium / Q000378:metabolism; D010042:Ouabain / Q000378:metabolism / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology / Q000652:urine*; D011247:Pregnancy; D011955:Receptors, Drug / Q000187:drug effects / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000097:blood*
D017705:Lignans; D010936:Plant Extracts; D011955:Receptors, Drug; C028996:cardiac glycoside receptors; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase
Lignanes de mammifères: une possible implication dans l'activité digitale endogène.