Myogenic Tone and Reactivity of the Rat Ophthalmic Artery

Yagna P R Jarajapu, Maria B. Grant, Harm J. Knot

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

PURPOSE. To study and quantify myogenic behavior and reactivity of the rat ophthalmic artery to pressure and different vasoactive substances in vitro. METHODS. Rat ophthalmic arteries (diameter of 217 ± 6 μm, n = 22) were isolated, cannulated with glass pipettes in an arteriograph and pressurized in a physiological buffer. Internal diameter was continuously monitored. The effect of intraluminal pressure on the diameter was assessed and concentration-response curves to different constrictor and dilator agonists were obtained at an intraluminal pressure of 70 mm Hg. RESULTS. Myogenic tone developed at an intraluminal pressure of 30 to 40 mm Hg, continued to increase, and was maintained up to a pressure of 199 mm Hg in these arteries. Arteries dilated and constricted in response to 16 and 60 mM potassium, respectively. Endothelin-1 was the most potent and efficacious constrictor, with a biphasic concentration-response curve, followed by vasopressin, serotonin, U-46619 and phenylephrine. Carbachol was the most efficacious dilator, followed by isoprenaline. The peptide dilators calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP) were potent but less efficacious than carbachol and isoprenaline. Histamine and adenosine were even less potent and less efficacious dilators. NG-nitro-L-arginine methyl ester (L-NAME) constricted and indomethacin dilated the arteries. CONCLUSIONS. This study provides the first direct evidence for myogenic autoregulatory properties and pharmacological heterogeneity in the rat ophthalmic artery.

Original languageEnglish (US)
Pages (from-to)253-259
Number of pages7
JournalInvestigative Ophthalmology and Visual Science
Volume45
Issue number1
DOIs
StatePublished - Jan 2004
Externally publishedYes

Fingerprint

Ophthalmic Artery
Pressure
Arteries
NG-Nitroarginine Methyl Ester
Carbachol
Isoproterenol
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid
Calcitonin Gene-Related Peptide
Vasoactive Intestinal Peptide
Phenylephrine
Endothelin-1
Vasopressins
Indomethacin
Adenosine
Histamine
Glass
Serotonin
Potassium
Buffers
Pharmacology

ASJC Scopus subject areas

  • Ophthalmology

Cite this

Myogenic Tone and Reactivity of the Rat Ophthalmic Artery. / Jarajapu, Yagna P R; Grant, Maria B.; Knot, Harm J.

In: Investigative Ophthalmology and Visual Science, Vol. 45, No. 1, 01.2004, p. 253-259.

Research output: Contribution to journalArticle

Jarajapu, Yagna P R ; Grant, Maria B. ; Knot, Harm J. / Myogenic Tone and Reactivity of the Rat Ophthalmic Artery. In: Investigative Ophthalmology and Visual Science. 2004 ; Vol. 45, No. 1. pp. 253-259.
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