Transposing results from an artificial minicell to a real cell. Experimental evidence for a working hypothesis linking Na,K-ATPase permeability states to specific alterations of cell life.
The present work sets in parallel data obtained with the Na,K-ATPase in artificial vesicular membranes (artificial minicells) and in peripheral human lymphocytes ex vivo. The Na,K-ATPase was purified and reconstituted into single-walled, tight liposomes filled with a reservoir of ATP and Na in which the Na,K-ATPase functions as in cells, that is, the receptor is accessible on the liposome surface (artificial minicells). In this system, an E2-ouabain state impermeable to Rb ions and an Na,K-ATPase-palytoxin state leaky for Rb ions were characterized. The tight E2-ouabain form preserves the viability of isolated lymphocytes, whereas the leaky Na,K-ATPase-palytoxin induces rapid cell bursting and death by a ouabain-sensitive mechanism. Thus, the effect of Na,K-ATPase inhibitors on lymphocyte survival can be predicted from permeability measurements in artificial minicells as verified also with the leak-inducing metals mercury and silver.
Anner
B M
BM
Department of Pharmacology, Geneva University Medical School, CMU, Switzerland. beatrice.anner@medecine.unige.ch
D000178:Acrylamides / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology; D002463:Cell Membrane Permeability; D002470:Cell Survival; D003064:Cnidarian Venoms / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008081:Liposomes; D008214:Lymphocytes / Q000166:cytology / Q000201:enzymology*; D008567:Membranes, Artificial; D008954:Models, Biological; D010713:Phosphatidylcholines; D012413:Rubidium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D000095702:Polyether Toxins
D000178:Acrylamides; D000255:Adenosine Triphosphate; D003064:Cnidarian Venoms; D008081:Liposomes; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D012413:Rubidium; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; C010272:palytoxin; D000095702:Polyether Toxins