Alpha2-adrenergic receptors in rat and rabbit eye: a tritium-sensitive film autoradiography

Ophthalmic Res. 1989;21(4):309-14. doi: 10.1159/000266875.


Using a tritium-sensitive film and [3H]-clonidine, alpha 2-adrenergic receptors were localized in entire eye sections of rabbits and rats. This radioactive agonist specifically labelled three structures in albino animals: ocular muscles, ciliary processes and retina. In pigmented animals, uvea with melanin was intensively but nonspecifically labelled. Microscopic analysis of autoradiograms obtained with iris-ciliary bodies, revealed that the major localization of binding sites was in the ciliary process epithelium. In displacement studies, [3H]-clonidine binding was inhibited by alpha 2-adrenergic compounds while alpha 1- or beta-selective drugs had no inhibitory effects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-Agonists / metabolism
  • Adrenergic alpha-Antagonists / metabolism
  • Animals
  • Autoradiography
  • Binding, Competitive
  • Clonidine / metabolism
  • Eye / analysis*
  • Rabbits
  • Rats
  • Receptors, Adrenergic, alpha / analysis*


  • Adrenergic alpha-Agonists
  • Adrenergic alpha-Antagonists
  • Receptors, Adrenergic, alpha
  • Clonidine