title: [The effect of pentoxifylline on the Ca2+-induced potassium efflux and on the ATPase-activity of erythrocytes (author's transl)].
abstract: The efflux of K+ from aged human erythrocytes is regulated by Ca2+: 5--100 mumol/l Ca2+ stimulate and 1--5 mmol/l Ca2+ inhibit K+-efflux. In fresh erythrocytes Ca2+ is virtually without effect on transport of K+. 3,7-Dimethyl-1-(5-oxohexyl)-xanthine (pentoxifylline) (5.5 mmol/l) decreases the K+-efflux from fresh erythrocytes by 10%. Similar effect of pentoxifylline is observed on the Ca2+-induced K+-efflux from aged erythrocytes. The ATPase-activity of a human erythrocyte membrane is stimulated in in vitro experiments by 1--100 mumol/l Ca2+. Increased concentration of Ca2+ (1--5 mmol/l), inhibits ATPase-activity. Pentoxifylline (0.5 mmol/l) modulates the effect of Ca2+ (conc. 1 mmol/l) on ATPase. It can be suggested that the rheological effect of pentoxifylline (possibly chelated with Ca2+) is caused by the decrease of Ca2+-caused K+-efflux and by the regulation of ATPase-activity of erythrocyte membrane.
mesh_terms: D000251:Adenosine Triphosphatases / Q000097:blood*; D002118:Calcium / Q000494:pharmacology*; D000252:Calcium-Transporting ATPases / Q000097:blood; D002463:Cell Membrane Permeability / Q000187:drug effects; D004905:Erythrocyte Aging / Q000187:drug effects; D004910:Erythrocyte Membrane / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D010431:Pentoxifylline / Q000494:pharmacology*; D011188:Potassium / Q000097:blood*; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood; D013805:Theobromine / Q000031:analogs & derivatives*
chemical_list: D000251:Adenosine Triphosphatases; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase; D013805:Theobromine; D011188:Potassium; D010431:Pentoxifylline; D002118:Calcium
vernacular_title: Die Wirkung von Pentoxifyllin auf den Ca++-induzierten Kalium-Ausstrom und auf die ATPase-Aktivität von Erythrozyten.