IOVS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Delaey, C.
Right arrow Articles by Van de Voorde, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Delaey, C.
Right arrow Articles by Van de Voorde, J.
(Investigative Ophthalmology and Visual Science. 2000;41:1871-1875.)
© 2000 by The Association for Research in Vision and Ophthalmology, Inc.

Pressure-Induced Myogenic Responses in Isolated Bovine Retinal Arteries

Christophe Delaey and Johan Van de Voorde

From the Department of Physiology and Pathophysiology, Ghent University, Belgium.

PURPOSE. To investigate whether a pressure-induced myogenic vasoconstriction can be demonstrated in isolated bovine retinal arteries and to determine the cellular mechanisms involved.

METHODS. Isolated bovine retinal arteries were mounted on a pressure myograph without flow and exposed to stepwise increases in intraluminal pressure. Changes in internal diameter were monitored continuously using an inverted microscope video system.

RESULTS. Bovine retinal arteries showed myogenic tone at pressures higher than 10 mm Hg. This pressure-induced contraction was absent in calcium-free Krebs–Ringer bicarbonate solution. Inhibition of L-type voltage-operated calcium channels with nifedipine (1 µM) suppressed the myogenic contraction. After depolarization of the vascular smooth muscle cells with a K+ 120 mM solution, a pressure-induced contraction was still observed, indicating that besides stimulation of voltage-operated calcium channels, depolarization-independent mechanisms contribute to the pressure-induced myogenic vasoconstriction.

CONCLUSIONS. Isolated bovine retinal arteries spontaneously contract when exposed to raised intraluminal pressure. This response depends on extracellular calcium and is blocked by nifedipine. In addition, depolarization-independent mechanisms seem to be involved.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2000 by the Association for Research in Vision and Ophthalmology