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Klin Monbl Augenheilkd 2001; 218(5): 338-340
DOI: 10.1055/s-2001-15894
EXPERIMENTELLE STUDIE

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 SchweinesThomas Morf, Peili Zhu, Josef Flammer, Ivan  O. Haefliger
  • Laboratory of Ocular Pharmacology and Physiology, University Eye Clinic Basel, Mittlere Straße 91, PO Box, CH-4012 Basel
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Publication History

Publication Date:
31 December 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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