Latanoprost is a vasoconstrictor in isolated porcine ciliary arteries.
OBJECTIVE
The purpose of this study was to assess the vasoconstrictor effect of the prostaglandin F2 alpha analog latanoprost in isolated porcine ciliary arteries.


METHODS
With a myograph system to measure isometric forces, porcine ciliary arteries were exposed, in a cumulative manner, to increasing concentrations of latanoprost (0.1 nM-0.1 mM). Experiments were conducted in quiescent vessels as well as in vessels precontracted with potassium chloride (KCl; 40 mM) or endothelin-1 (10 nM). Contractions were expressed in percent of 100 mM KCl-induced contraction.


RESULTS
In a concentration dependent manner latanoprost induced significant (p < 0.001) contractions in quiescent vessels (maximum: 68 +/- 3%, n = 5; PD50: 5.7 +/- 0.1). In KCl or in endothelin-1 precontracted vessels latanoprost did not evoke any relaxation but in contrast significant (p < 0.001) contractions (maximum: 33 +/- 4%, n = 5 and 26 +/- 6%, n = 8, respectively).


CONCLUSIONS
Latanoprost has a vasoconstrictor effect in isolated porcine ciliary arteries. No relaxation could be observed. The clinical relevance of this finding requires further evaluation.
Brogiolo
G
G
Laboratory of Ocular Pharmacology and Physiology, University Eye Clinic Basel, Mittlere Strasse 91, PO Box, CH-4012 Basel, Switzerland.
Flammer
J
J
Haefliger
I O
IO
D000818:Animals; D019842:Ciliary Arteries / Q000187:drug effects*; D046508:Culture Techniques; D015237:Dinoprost / Q000031:analogs & derivatives*; D004305:Dose-Response Relationship, Drug; D007429:Intraocular Pressure / Q000187:drug effects; D000077338:Latanoprost; D011461:Prostaglandins F, Synthetic / Q000494:pharmacology*; D013552:Swine; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D011461:Prostaglandins F, Synthetic; D014662:Vasoconstrictor Agents; D000077338:Latanoprost; D015237:Dinoprost