title: Endothelin-induced changes in intracellular calcium concentration in rat vascular smooth muscle cells: effects of extracellular calcium and atrial natriuretic factor.
abstract: The purpose of this study was to examine whether different mechanisms might underlie the changes in intracellular calcium concentration ([Ca2+]i) stimulated by high and low concentrations of endothelin, and whether atrial natriuretic factor (ANF) has an inhibitory effect on endothelin-induced [Ca2+]i changes in cultured rat vascular smooth muscle cells (VSMCs). In calcium-replete buffer, cultured monolayers of rat VSMCs superfused with endothelin at a high concentration (10 nM) exhibited a marked transient rise in [Ca2+]i, followed by a sustained elevation, whereas a low concentration of endothelin (0.1 nM) induced a sustained monophasic elevation. When calcium-free buffer was used, 10 nM endothelin induced a transient rise in [Ca2+]i of lesser amplitude, whereas 0.1 nM endothelin did not produce a significant rise. Pretreatment of VSMCs with ANF and cosuperfusion with endothelin failed to inhibit either transient or sustained endothelin-induced changes in [Ca2+]i in calcium-replete buffer.
authors.affiliation: Department of Cardiology, Princess Margaret Hospital, Christchurch, New Zealand.
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: T J
authors.initials: TJ
authors.lastname: Abell
authors.forename: A M
authors.initials: AM
authors.lastname: Richards
authors.forename: H
authors.initials: H
authors.lastname: Ikram
authors.forename: E A
authors.initials: EA
authors.lastname: Espiner
authors.forename: T G
authors.initials: TG
authors.lastname: Yandle
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000502:physiology*; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000502:physiology*; D046508:Culture Techniques; D016232:Endothelins / Q000502:physiology*; D005110:Extracellular Space / Q000378:metabolism*; D007424:Intracellular Fluid / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D014661:Vasoconstriction / Q000502:physiology*
chemical_list: D015220:Calcium Channels; D016232:Endothelins; C472610:atrial natriuretic peptide, rat; D009320:Atrial Natriuretic Factor; D002118:Calcium