Protective effects of nebivolol on oxygen free radical-induced vasoconstrictions in vitro.

TY - JOUR

T1 - Protective effects of nebivolol on oxygen free radical-induced vasoconstrictions in vitro.

AU - Wagenfeld, Lars

AU - Himpel, Okko

AU - Galambos, Peter

AU - Matthiesen, Nataliya

AU - Wiermann, Anne

AU - Richard, Gisbert

AU - Klemm, Maren

AU - Zeitz, Oliver

PY - 2008

Y1 - 2008

N2 - BACKGROUND: Disturbed ocular hemodynamics and vasospasms might be involved in the pathogenesis of glaucoma. On a clinical level there are indications for an optimization of ocular perfusion parameters in hypertensive glaucoma patients by switching a beta-adrenoceptor-antagonist therapy to nebivolol. Aim of the present study is to investigate vasoactive properties of nebivolol on ocular vasculature in vitro. Besides vasorelaxing effects, the impact of nebivolol on oxygen free radical-induced vasoconstrictions is studied. MATERIAL/METHODS: The experiments were carried out with ring preparations from porcine ciliary arteries. The preparations were placed in a myograph system and were kept under physiological conditions (pH 7.4, 37 degrees C, Krebs-Henseleit-Buffer, 1.75 mM Ca2+) and were stimulated by K+ depolarizations. The experiments were performed at a Nernst potential of -41 mV, which reflects half-maximal activation. For radical exposure, the preparations were superfused for 20 s in a specifically designed set-up with hydroxyl radicals generated by the Fenton reaction from H2O2 and Fe3+. NO synthase activity was modulated by adding L-arginine to the buffer. RESULTS: At a concentration of 10-5 M nebivolol leads to a reduction of vascular tone by -8.5+/-3.4% (n=11; P=0.016) vs. +2.6+/-1.9% (n=11; n.s.) in presence of its solvent DMSO. Nebivolol (10-5 M) reduces hydroxyl radical-induced vasoconstrictions by 53+/-10% (n=11; P

AB - BACKGROUND: Disturbed ocular hemodynamics and vasospasms might be involved in the pathogenesis of glaucoma. On a clinical level there are indications for an optimization of ocular perfusion parameters in hypertensive glaucoma patients by switching a beta-adrenoceptor-antagonist therapy to nebivolol. Aim of the present study is to investigate vasoactive properties of nebivolol on ocular vasculature in vitro. Besides vasorelaxing effects, the impact of nebivolol on oxygen free radical-induced vasoconstrictions is studied. MATERIAL/METHODS: The experiments were carried out with ring preparations from porcine ciliary arteries. The preparations were placed in a myograph system and were kept under physiological conditions (pH 7.4, 37 degrees C, Krebs-Henseleit-Buffer, 1.75 mM Ca2+) and were stimulated by K+ depolarizations. The experiments were performed at a Nernst potential of -41 mV, which reflects half-maximal activation. For radical exposure, the preparations were superfused for 20 s in a specifically designed set-up with hydroxyl radicals generated by the Fenton reaction from H2O2 and Fe3+. NO synthase activity was modulated by adding L-arginine to the buffer. RESULTS: At a concentration of 10-5 M nebivolol leads to a reduction of vascular tone by -8.5+/-3.4% (n=11; P=0.016) vs. +2.6+/-1.9% (n=11; n.s.) in presence of its solvent DMSO. Nebivolol (10-5 M) reduces hydroxyl radical-induced vasoconstrictions by 53+/-10% (n=11; P

M3 - SCORING: Zeitschriftenaufsatz

VL - 14

SP - 109

EP - 112

JO - MED SCI MONITOR

JF - MED SCI MONITOR

SN - 1643-3750

IS - 6

M1 - 6

ER -