|
|
||||||||
Investigative Ophthalmology & Visual Science, Vol 38, 1563-1568, Copyright © 1997 by Association for Research in Vision and Ophthalmology
ARTICLES AND REPORTS |
IO Haefliger and DR Anderson
Department of Opthalmology, Bascom Palmer Eye Institute, University Miami School of Medicine, Florida, USA.
PURPOSE: This study explores at which level of the guanylate cyclase pathway oxygen modulates retinal pericyte relaxation induced by nitric oxide (NO). METHODS: Bovine retinal microvascular pericytes were grown on silicone. On silicone, pericyte contractile tone induces wrinkles. Drug-induced relaxation was quantified as a reduced number of wrinkles after exposure to 3-morpholino-sydnonimine (SIN-1) or atrial natriuretic peptide (ANP) in the absence or in the presence of either 0.3 microM methylene blue (MB), a guanylate cyclase inhibitor, or 10 microM hemoglobin, a NO scavenger; and under 100% oxygen (hyperoxia), ambient air (normoxia), or 100% nitrogen (hypoxia). RESULTS: Pericytes were relaxed with SIN-1 and ANP in a concentration-dependent manner (EC50: 0.1 microM and 0.01 microM, respectively). Relaxations induced by SIN-1 or ANP were inhibited (P < 0.001) by MB, whereas hemoglobin inhibited only SIN-1 relaxations (P < 0.001). Relaxations induced by SIN-1, but not by ANP were increased (P < 0.001) under hypoxia and decreased (P = 0.002) under hyperoxia. CONCLUSIONS: SIN-1 and ANP relax pericytes through the activation of guanylate cyclase (inhibited by MB), but only SIN-1 through an extracellular release of NO (inhibited by hemoglobin). That oxygen only modulates pericyte relaxations induced by SIN-1 (NO-mediated) but not those induced by ANP suggests that an interaction between oxygen and NO might participate in the capillary network's blood-flow modulation according to local tissue oxygen tension.
This article has been cited by other articles:
![]() |
C. J. Pournaras, E. Logean, C. E. Riva, B. L. Petrig, S. R. Chamot, G. Coscas, and G. Soubrane Regulation of subfoveal choroidal blood flow in age-related macular degeneration. Invest. Ophthalmol. Vis. Sci., April 1, 2006; 47(4): 1581 - 1586. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Dallinger, G. T. Dorner, R. Wenzel, U. Graselli, O. Findl, H.-G. Eichler, M. Wolzt, and L. Schmetterer Endothelin-1 Contributes to Hyperoxia-Induced Vasoconstriction in the Human Retina Invest. Ophthalmol. Vis. Sci., March 1, 2000; 41(3): 864 - 869. [Abstract] [Full Text] |
||||
![]() |
C. C. Michel and F. E. Curry Microvascular Permeability Physiol Rev, July 1, 1999; 79(3): 703 - 761. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |