title: Cell membrane potential oscillations induced by kinins in fibroblasts expressing the Ha-ras oncogene.
abstract: In NIH-3T3 fibroblasts expressing the ras oncogene (+ras) bradykinin (BK) elicits sustained oscillations (1/min) of cell membrane potential (PD) due to oscillations of intracellular calcium activity with subsequent activation of calcium sensitive K+ channels. In NIH-3T3 fibroblasts not expressing the oncogene (-ras), BK leads to a single transient hyperpolarization of the cell membrane, not followed by oscillations. The oscillations of cell membrane potential require the presence of extracellular calcium and are abolished by K+ channel blocker barium (1 mmol/l), as well as by calcium channel blockers cadmium (1 mmol/l), lanthanum (0.1 mmol/l) and nifedipine (10 mumol/l). However, the oscillations are not modified by 1 mumol/l nifedipine, or by other calcium channel blockers, such as verapamil (10 mumol/l) or diltiazem (10 mumol/l). Cell proliferation is inhibited by nifedipine (10 mumol/l) but not by verapamil or diltiazem, indicating that the oscillations of intracellular calcium are a prerequisite for the growth factor independent proliferation of ras oncogene expressing cells.
authors.affiliation: Institute for Physiology, University of Innsbruck, Austria.
authors.forename: F
authors.initials: F
authors.lastname: Lang
authors.forename: E
authors.initials: E
authors.lastname: Wöll
authors.forename: S
authors.initials: S
authors.lastname: Waldegger
authors.forename: F
authors.initials: F
authors.lastname: Friedrich
authors.forename: M
authors.initials: M
authors.lastname: Ritter
authors.forename: G
authors.initials: G
authors.lastname: Pinggera
authors.forename: K
authors.initials: K
authors.lastname: Kloiber
authors.forename: I
authors.initials: I
authors.lastname: Bichler
authors.forename: H
authors.initials: H
authors.lastname: Heitzenberger
authors.forename: K
authors.initials: K
authors.lastname: Maly
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001464:Barium / Q000494:pharmacology; D001920:Bradykinin / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology*; D002471:Cell Transformation, Neoplastic; D005347:Fibroblasts / Q000502:physiology; D011905:Genes, ras; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D014162:Transfection
chemical_list: D002121:Calcium Channel Blockers; D001464:Barium; D001920:Bradykinin; D002118:Calcium