TY - JOUR
T1 - Drug Effects on Intraocular Pressure and Vascular Flow in the Bovine Perfused Eye Using Radiolabelled Microspheres
AU - Millar, J. C.
AU - Wilson, W. S.
AU - Carr, R. D.
AU - Humphries, R. G.
PY - 1995
Y1 - 1995
N2 - A novel technique is described in which the effect of the β-adrenoceptor antagonists timolol and carteolol, and the vasodilators sodium nitroprusside (SNP) and verapamil on intraocular pressure (IOP) and the distribution of ocular flow in the bovine arterially perfused eye is investigated using radiolabelled microspheres. At maximum IOP-reducing dose timolol was found to significantly reduce perfusion in the choroid and, at higher dose, it was found to significantly reduce perfusion in the iris. By contrast, a maximal IOP-reducing dose of carteolol markedly reduced perfusion in the iris, ciliary body and choroid. Vasoconstriction induced by carteolol was not inhibited by the α-antagonist phentolamine. Against a background of vascular tone induced by noradrenaline, SNP and verapamil were found to significantly increase perfusion in the iris, ciliary body and choroid. The effects of these drugs upon the vasculature of the bovine perfused eye are varied and complex and may not bear a direct relationship to their ocular hypotensive effect.
AB - A novel technique is described in which the effect of the β-adrenoceptor antagonists timolol and carteolol, and the vasodilators sodium nitroprusside (SNP) and verapamil on intraocular pressure (IOP) and the distribution of ocular flow in the bovine arterially perfused eye is investigated using radiolabelled microspheres. At maximum IOP-reducing dose timolol was found to significantly reduce perfusion in the choroid and, at higher dose, it was found to significantly reduce perfusion in the iris. By contrast, a maximal IOP-reducing dose of carteolol markedly reduced perfusion in the iris, ciliary body and choroid. Vasoconstriction induced by carteolol was not inhibited by the α-antagonist phentolamine. Against a background of vascular tone induced by noradrenaline, SNP and verapamil were found to significantly increase perfusion in the iris, ciliary body and choroid. The effects of these drugs upon the vasculature of the bovine perfused eye are varied and complex and may not bear a direct relationship to their ocular hypotensive effect.
UR - http://www.scopus.com/inward/record.url?scp=0029002011&partnerID=8YFLogxK
U2 - 10.1089/jop.1995.11.11
DO - 10.1089/jop.1995.11.11
M3 - Article
C2 - 8535953
AN - SCOPUS:0029002011
SN - 1080-7683
VL - 11
SP - 11
EP - 23
JO - Journal of Ocular Pharmacology and Therapeutics
JF - Journal of Ocular Pharmacology and Therapeutics
IS - 1
ER -