Abstract
Purpose: :
Prostaglandin analogues are used to reduce intraocular pressure in glaucoma. These drugs affect aqueous humor dynamics, probably involving effects on the tone of arteries supplying the ciliary body. These effects can be assumed to be mediated by prostaglandin receptors previously identified in ocular tissue.
Methods: :
The intraocular part of porcine ciliary arteries was isolated and mounted in a myograph system for isometric recording of vascular tone. The effect of adding increasing concentrations of PGD2, PGE2, two PGF2α agonists and PGI2 in the concentration range of 10-9 M-10-5 M was studied with and without precontraction with noradrenaline (NA) 10-6 M.
Results: :
In noradrenaline contracted arteries, PGF2α agonists and PGD2 increased the vascular tone dose-dependently, PGE2 induced a dose-dependent vasorelaxation, whereas PGI2 had no effect on the vascular tone.
Conclusions: :
Prostaglandins with affinity to receptors previously identified in ocular tissue have vasoactive effects on intraocular porcine ciliary vessels in vitro. The findings may be translated to clinical trials with the purpose of reducing the intraocular pressure in glaucoma.
Keywords: blood supply • aqueous • ciliary body