The interaction of testosterone, androsterone, dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEAS) with erythrocyte membranes was studied. It was shown that testosterone and androsterone have a high constant of binding to the membranes (K(b) approximate to 10(6) M(-1)), whereas K(b)'s for DHEA and DHEAS are 2 orders of magnitude lower. Hydrogen bonds and hydrophobic interactions play an important role in binding of anabolic steroids. Hydrogen bonds form with CO and NH groups both of membrane proteins and phospholipids. This results in the formation of complex domains rising above the surface of membranes. Strengthening of hydrophobic interactions in the domains promotes the displacement of water dipoles to adjacent regions, thus loosening the phospholipid bilayer. Overall, microviscosity of erythrocyte membranes strongly increases, which decreases the plasticity of erythrocytes and hampers their motion in blood capillaries. This mechanism may underlie the development of diffusion myocardial hypoxia and hypoxic cardiac arrest.