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DOI: 10.1055/s-2001-15894
Georg Thieme Verlag Stuttgart · New York
Vasorelaxing effect of the potassium (K+)-channel opener pinacidil in isolated porcine ciliary arteries
Vasorelaxierende Eigenschaften von Pinacidil an isolierten Ziliararterien des SchweinesPublikationsverlauf
Publikationsdatum:
31. Dezember 2001 (online)
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Hintergrund Die vorliegende pharmakologische Studie wurde durchgeführt, um die vasorelaxierende Wirkung von Pinacidil (ein Kalium-Kanal-Öffner) an isolierten Ziliararterien des Schweines zu evaluieren.
Material und Methoden An Ziliararterien wurde mittels eines Myographsystems die isometrische Kraft bei kumulativ zunehmenden Konzentrationen (1 nM - 100 μM) von Pinacidil gemessen. Die Experimente wurden an durch Thromboxane A2 Analogon U 46619 (0,1 μM) präkontrahierten Ziliararterien durchgeführt. Relaxationen wurden in Prozent einer durch U 46619 (0,1 μM) induzierten Kontraktion exprimiert.
Ergebnisse Pinacidil zeigte eine starke konzentrationsabhängige Abnahme der Kontraktionskraft in mit U 46619 präkontrahierten Ziliararterien (100 μM: 112 ± 2 %; n=7). Dieser Effekt war signifikant (p < 0,0001) verschieden von einer Kontrollgruppe (18 ± 6 %; n=6). Die Konzentration von Pinacidil, welche 50 % der maximalen Relaxation induzierte (pD50), betrug 5,3 ± 0,1 (- log M).
Schlussfolgerung Pinacidil zeigt an isolierten Ziliararterien des Schweines starke vasorelaxierende Eigenschaften.
Abstract
Purpose The aim of this study was to investigate the vasorelaxing properties of pinacidil (a potassium-channel-opener) in isolated porcine ciliary arteries.
Methods Isometric contractions of isolated porcine ciliary arteries were measured with a myograph system. The vessels were first precontracted with the thromboxane A2 analog U 46619 (0.1 μM), and then exposed, in a cumulative manner, to increasing concentrations of pinacidil (1 nM - 100 μM). Relaxations have been expressed in percent of the maximal contraction evoked by U 46619 (0.1 μM).
Results Pinacidil showed a pronounced concentration-dependent relaxing effect in isolated porcine ciliary arteries. The difference between pinacidil and time-control experiments was significant (100 μM: 112 ± 2 % vs. 18 ± 6 %, P < 0.0001). The half-maximal concentration (pD50) value was 5.3 ± 0.1 (- log M).
Conclusions The present study indicates that pinacidil has marked vasorelaxing properties in isolated porcine ciliary arteries.
Schlüsselwörter
Normaldruckglaukom - vaskuläre Risikofaktoren - okulärer Blutfluss - Augeninnendruck - Glaukom-Therapie
Key words
normal tension glaucoma - vascular risk factor - ocular blood flow
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