Endogenous digitalis-like factors (EDLF) (EDLF)

Endogenous digitalis-like factors (EDLFs), also known as endogenous cardiotonic steroids, are a group of steroid hormones produced primarily in the adrenal glands and hypothalamus that structurally resemble plant-derived digitalis compounds [3, 4]. These factors, which include endogenous ouabain and marinobufagenin, function as physiological regulators of the Na+/K+-ATPase (sodium-potassium pump) [8, 12]. By binding to the extracellular domain of the alpha subunit of this enzyme, EDLFs inhibit its ion transport activity, leading to increased intracellular sodium and calcium concentrations, which enhances cardiac contractility and promotes vasoconstriction [1, 14]. Beyond ion transport, EDLFs act as signaling ligands that trigger the Src-EGFR-MAPK pathway, influencing cell proliferation and fibrosis [1, 13]. Pathologically, elevated levels of EDLFs are strongly associated with the development of volume-dependent hypertension, preeclampsia, and organ damage in chronic kidney and heart disease [2, 6, 8]. Therapeutic strategies targeting EDLFs involve the use of neutralizing antibodies, such as digoxin immune fab, or specific antagonists like rostafuroxin to mitigate their hypertensive and pro-fibrotic effects [5, 10, 11].

Other names

Endogenous cardiotonic steroids (ECTS)Endogenous ouabain (EO)Marinobufagenin (MBG)Digoxin-like immunoreactive substances (DLIS)Endogenous digitalis-like substances (EDLS)Sodium pump inhibitors

Immunoneutralization of circulating factors to prevent pump inhibition; competitive antagonism of the digitalis binding site on Na+/K+-ATPase; inhibition of EDLF-induced Src-dependent signaling pathways.