December 2002
Volume 43, Issue 13
Free
ARVO Annual Meeting Abstract  |   December 2002
Role of NO in Choroidal Blood Flow Regulation During Isometric Exercise in Healthy Humans
Author Affiliations & Notes
  • A Luksch
    Clinical Pharmacology University Vienna Vienna Austria
  • EA Polska
    Clinical Pharmacology University Vienna Vienna Austria
  • G Fuchsjager-Mayrl
    Clinical Pharmacology University Vienna Vienna Austria
  • M Wolzt
    Clinical Pharmacology University Vienna Vienna Austria
  • L Schmetterer
    Clinical Pharmacology University Vienna Vienna Austria
  • Footnotes
    Commercial Relationships   A. Luksch, None; E.A. Polska, None; G. Fuchsjager-Mayrl, None; M. Wolzt, None; L. Schmetterer, None. Grant Identification: FWF Grant P-14219
Investigative Ophthalmology & Visual Science December 2002, Vol.43, 3308. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      A Luksch, EA Polska, G Fuchsjager-Mayrl, M Wolzt, L Schmetterer; Role of NO in Choroidal Blood Flow Regulation During Isometric Exercise in Healthy Humans . Invest. Ophthalmol. Vis. Sci. 2002;43(13):3308.

      Download citation file:


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

      ×
  • Supplements
Abstract

Abstract: : Purpose: Nitric oxide (NO) is an important regulator of basal choroidal blood flow. Animal experiments indicate that NO is also involved in choroidal autoregulation and NO synthase (NOS) inhibition and has been reported to shift choroidal pressure/flow curves to the right. We hypothesized that NOS inhibition may influence choroidal blood flow during isometric exercise. Methods: To test this hypothesis we performed a randomized, double-masked, placebo-controlled, three way cross over study in 12 healthy male volunteers. Subjects received on different study days intravenous infusions of NG-monomethyl-L-arginine (L-NMMA), phenylephrine or placebo. During these infusion periods subjects performed squatting for 6 minutes. Choroidal blood flow was assessed with laser Doppler flowmetry and ocular perfusion pressure (OPP) was calculated from mean arterial pressure and intraocular pressure. Results: L-NMMA and phenylephrine increased resting OPP by 10% and 13%, respectively, but only L-NMMA reduced resting choroidal blood flow (-17%, p < 0.001). The relative increase in OPP during isometric exercise was comparable with all administered drugs. Isometric exercise increased choroidal blood flow during placebo and phenylephrine administration, but not during administration of L-NMMA (p < 0.001 versus placebo). Conclusion: These data indicate that NO plays an important role in the regulation of choroidal blood flow during isometric exercise.

Keywords: 345 choroid • 491 nitric oxide • 514 pharmacology 
×
×

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.

×