| Reference : Pertussis toxin-sensitive G(i)-proteins and intracellular calcium sensitivity of vaso... |
| Scientific journals : Article | |||
| Life sciences : Biochemistry, biophysics & molecular biology | |||
| http://hdl.handle.net/10993/5724 | |||
| Pertussis toxin-sensitive G(i)-proteins and intracellular calcium sensitivity of vasoconstriction in the intact rat tail artery | |
| English | |
| Spitzbarth-Régrigny, E. [> >] | |
| Petitcolin, M. A. [> >] | |
Bueb, Jean-Luc  [University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Life Science Research Unit >] | |
| Tschirhart, Eric [University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Life Science Research Unit >] | |
| Atkinson, J. [> >] | |
| Capdeville-Atkinson, C. [> >] | |
| 2000 | |
| British Journal of Pharmacology | |
| Nature Publishing Group | |
| 131 | |
| 7 | |
| 1337-44 | |
| Yes (verified by ORBilu) | |
| 0007-1188 | |
| London | |
| United Kingdom | |
| [en] pharmacology ; Pertussis Toxin ; Norepinephrine ; Membranes ; Male ; Immunoblotting ; GTP-Binding Protein alpha Subunits, Gi-Go ; Dose-Response Relationship, Drug ; Calcium ; Arteries ; Potassium Chloride ; Rats ; blood supply ; metabolism ; physiology ; drug effects ; chemistry ; Virulence Factors, Bordetella ; Vasoconstriction ; Tail ; Rats, Wistar ; Animals | |
| [en] 1. We studied the involvement of pertussis toxin (PTX)-sensitive G-proteins in the sensitivity of arterial constriction to intracellular calcium ([Ca(2+)](i)) mobilization. 2. Vasoconstriction was measured in vitro in perfused, de-endothelialized rat tail arteries loaded with the calcium-sensitive dye, fura-2 and treated or not with PTX (30 - 1000 ng ml(-1)). Arteries were stimulated with noradrenaline (NA, 0.1 - 100 microM) or KCl (15 - 120 mM). 3. KCl elicited a smaller vasoconstrictor response (E(max)=94+/-8 mmHg) than NA (E(max)=198+/-9 mmHg) although [Ca(2+)](i) mobilization was similar (E(max)=123+/-8 and 135+/-7 nM for KCl and NA, respectively). PTX (1000 ng ml(-1)) had no effect on [Ca(2+)](i) mobilization but lowered NA- (but not KCl-) induced vasoconstriction (E(max)=118+/-7 mmHg). 4. G(i/o)-proteins were revealed by immunoblotting with anti-G(i alpha) and anti-G(o alpha) antibodies in membranes prepared from de-endothelialized tail arteries. [alpha(32)P]-ADP-ribosylation of G-proteins by PTX (1000 ng ml(-1)) was demonstrated in the intact rat tail artery (pixels in the absence of PTX: 3150, presence: 25053). 5. In conclusion, we suggest that smooth muscle cells possess a PTX-sensitive G(i)-protein-mediated intracellular pathway which amplifies [Ca(2+)](i) sensitivity of contraction in the presence of agonists such as NA. | |
| http://hdl.handle.net/10993/5724 | |
| 10.1038/sj.bjp.0703703 |
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