Differential effects of selective 287-1287-1287-1287-2287-2287-2agonists on intraocular pressure in the conscious rabbit

Abstract

In the present study the influence of topically applied selective α₁ and α₂-adrenoceptor agonists on intraocular pressure and the diameter of the pupil was investigated in conscious rabbits. Selective stimulation of the α₁-subtype of receptors induced an elevation in intraocular pressure, accompanied by mydriasis, whereas stimulation of the α₂-subtype caused a marked and dose-dependent ocular hypotensive response, which could be blocked by the selective α₂-adrenoceptor antagonist yohimbine. After application of the non-selective α-adrenoceptor agonist clonidine the α₂-adrenoceptor mediated decrease in IOP is probably counteracted by a pressor effect due to the stimulation of α₁-adrenoceptors.