The comparison of vanadyl (IV) and insulin-induced hyperpolarization of the mammalian muscle cell.
Extracellularly applied vanadyl (IV) hyperpolarized the membrane potential of mouse diaphragm muscle from about -74.0 mV up to -81.7 mV. The hyperpolarizing effect of 10(-4) mol.I-1 vanadyl (IV) is comparable with hyperpolarization induced by 100 mU.ml-1 insulin. Both compounds increased the intracellular K+ concentration, the hyperpolarizing effect of vanadyl (IV) and insulin is blocked by ouabain and is unaffected by removal of K+ from the external medium. Triggering of the release of intracellular K+ associated with cellular proteins is proposed as the mechanism of vanadyl (IV) and insulin-induced hyperpolarization.
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D003964:Diaphragm / Q000502:physiology; D005260:Female; D007328:Insulin / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D010042:Ouabain / Q000494:pharmacology; D014638:Vanadates; D014639:Vanadium / Q000494:pharmacology*
D007328:Insulin; D014639:Vanadium; D014638:Vanadates; D010042:Ouabain