Vasoactive properties of bimatoprost in isolated porcine ciliary arteries.
BACKGROUND
To investigate the vasoactive effect of bimatoprost (Lumigan), a new topical ocular hypotensive agent, in isolated porcine ciliary arteries.


METHODS
Arteries were placed in a myograph system to measure isometric forces. Quiescent vessels as well as vessels pre-contracted with either 10 nM endothelin-1 or 100 mM potassium chloride (KCl) were exposed, in a cumulative manner, to increasing concentrations (0.1 nM - 0.1 mM) of bimatoprost (dissolved in ethanol). In quiescent vessels, results were expressed in percent of 100 mM KCl-induced contraction. In endothelin-1-pre-contracted vessels, results were expressed in percent of the maximal contraction induced by endothelin-1. In KCl-pre-contracted vessels, results were expressed in percent of the plateau contraction reached 30 minutes after 100 mM KCl application.


RESULTS
Bimatoprost induced a significant (p < 0.05 - 0.001) vasoconstriction at concentrations equal to or higher than 0.1 micro M in quiescent vessels (0.1 mM: 73 +/- 12 %). In KCl-pre-contracted vessels, at concentrations higher than 1 micro M, bimatoprost induced significant (p < 0.05 - 0.01) contractions (0.1 mM: 67 +/- 17 %). In endothelin-1-pre-contracted vessels, bimatoprost also induced significant (p < 0.05 - 0.001) contractions at concentrations above 10 micro M (0.1 mM: 17 +/- 8 %).


CONCLUSIONS
The present study indicates that bimatoprost appears to have, in vitro, some vasoactive properties in porcine ciliary arteries. The question whether Lumigan has an influence on ocular blood flow needs to be further investigated.
Allemann
Reto
R
Laboratory of Ocular Pharmacology and Physiology, University Eye Clinic Basel, Switzerland.
Flammer
Josef
J
Haefliger
Ivan O
IO
D000577:Amides; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001082:Aqueous Humor / Q000378:metabolism; D000069580:Bimatoprost; D003008:Cloprostenol / Q000031:analogs & derivatives; D046508:Culture Techniques; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000494:pharmacology; D005901:Glaucoma / Q000503:physiopathology; D007429:Intraocular Pressure / Q000187:drug effects; D008055:Lipids / Q000494:pharmacology*; D018917:Optic Neuropathy, Ischemic / Q000503:physiopathology; D011189:Potassium Chloride / Q000494:pharmacology; D011461:Prostaglandins F, Synthetic / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects; D013552:Swine; D014661:Vasoconstriction / Q000187:drug effects
D000577:Amides; D000959:Antihypertensive Agents; D019332:Endothelin-1; D008055:Lipids; D011461:Prostaglandins F, Synthetic; D003008:Cloprostenol; D011189:Potassium Chloride; D000069580:Bimatoprost