May 2007
Volume 48, Issue 13
Free
ARVO Annual Meeting Abstract  |   May 2007
Oxygen Free Radical Induced Vasospasm of Porcine Ciliary Arteries: Protective Effects of Nebivolol
Author Affiliations & Notes
  • L. Wagenfeld
    Eye-Clinic, University of Hamburg, Hamburg, Germany
  • O. Zeitz
    Eye-Clinic, University of Hamburg, Hamburg, Germany
  • O. Himpel
    Eye-Clinic, University of Hamburg, Hamburg, Germany
  • P. Galambos
    Eye-Clinic, University of Hamburg, Hamburg, Germany
  • A. Wiermann
    Eye-Clinic, University of Hamburg, Hamburg, Germany
  • N. Matthiesen
    Eye-Clinic, University of Hamburg, Hamburg, Germany
  • G. Richard
    Eye-Clinic, University of Hamburg, Hamburg, Germany
  • M. Klemm
    Eye-Clinic, University of Hamburg, Hamburg, Germany
Investigative Ophthalmology & Visual Science May 2007, Vol.48, 2255. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      L. Wagenfeld, O. Zeitz, O. Himpel, P. Galambos, A. Wiermann, N. Matthiesen, G. Richard, M. Klemm; Oxygen Free Radical Induced Vasospasm of Porcine Ciliary Arteries: Protective Effects of Nebivolol. Invest. Ophthalmol. Vis. Sci. 2007;48(13):2255.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose:: Vasospasms are discussed to play a role in the pathogenesis of glaucoma. A possible mechanism how vasospasm can be induced is a free radical exposure. For Nebivolol scavenger properties have been postulated. There are indications that Nebivolol improves ocular hemodynamics (ARVO meeting 2006, Poster-Nr.: 485-B239). Aim of this study is to investigate if a radical induced vasospasm of porcine ciliary arteries can be reduced by Nebivolol in an in vitro experiment.

Methods:: Rings of isolated porcine ciliary arteries were mounted in a force myograph and kept in an almost physiological environment (Krebs-Henseleit-Buffer, pH=7.4, 37° C). Two full contractions were performed by depolarizing the arteries by rising the extracellular potassium to a concentration of 120 mM. Afterwards half maximal contractions were induced by 30mM potassium in the extracellular solution. These pre-contracted arteries were exposed to various concentrations (10-6 to 10-3 M) of Nebivolol or equivalent amounts of its solvent DMSO. Oxygen free radicals (OFR) from the Fenton reaction (H2O2 + Fe3+ -> -OH) were added to initiate the contractions. The rise in force was recorded and compared between the tested concentrations of Nebivolol. To make results more comparable all forces were normalized on the second full contraction. All statistical analysis was done with these normalized values to minimize errors.

Results:: Higher concentrations of Nebivolol lead to a more pronounced inhibition of the OFR induced vasospasm (0.22 ± 0.04 with 10-6 M Nebivolol vs. 0.27± 0.09 with equivalent amounts of DMSO, p=0.59, n=6; 0.14 ± 0.01 with 10-5 M Nebivolol vs. 0.36 ± 0.05 with DMSO, p=8*10-5, n=11; 0.09 ± 0.02 with 10-4 M Nebivolol vs. 0.38 ± 0.05 with DMSO, p=4*10-6, n=11; 0.04 ± 0.02 with 10-3 Nebivolol vs. 0.15 ± 0.03 with DMSO, p=0.01, n=6). ANOVA testing shows that this effect is dose dependent and all steps are significant except the step from 0 M to 10-6 M.

Conclusions:: These data implicate that Nebivolol has a pronounced scavenger effect. Following our data Nebivolol has the capability to reduce OFR induced vasospasms in vitro and may have protective effects for glaucoma patients.

Keywords: oxidation/oxidative or free radical damage • blood supply • antioxidants 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×