title: The influence of clonidine on intraocular pressure.
abstract: In order to study the influence of clonidine on intraocular pressure (IOP), the drug was administered via different routes. The experiments were performed on chloralose-anaesthetized cats. The rise in IOP observed after administration of clonidine into the external carotid arteries was subjected to a pharmacological analysis. Our experiments suggest that the increase in IOP is due to the contraction of eyelids and extraocular muscles, mediated by the influence of clonidine on alpha-adrenoceptors. The IOP-lowering effect of clonidine was more pronounced after its infusion into the left vertebral artery than after its intravenous injection. This difference would suggest that the clonidine-induced decrease in IOP may be mediated via a central mechanism.
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001933:Brain Stem / Q000502:physiology; D002342:Carotid Artery, External; D002415:Cats; D003000:Clonidine / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005268:Femoral Vein; D007269:Injections, Intra-Arterial; D007275:Injections, Intravenous; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D014711:Vertebral Artery
chemical_list: D003000:Clonidine