title: Presence of opioid growth factor and its receptor in the normal dog, cat and horse cornea.
abstract: OBJECTIVE
  To determine if opioid growth factor (OGF, [Met5]enkephalin) and its specific receptor (OGFr) are present in normal cat, dog and horse cornea.
  
  
  METHODS
  Normal dog, cat and horse.
  
  
  METHODS
  Corneas were obtained from animals euthanized for reasons unrelated to this project. One cornea from each of three normal cats, dogs and horses was evaluated. The right or left cornea from each animal was chosen randomly. Corneas were harvested and placed in corneal storage media for transport to The M.S. Hershey Medical Center of The Pennsylvania State University where immunocytochemistry techniques were used to demonstrate the presence and location of OGF and OGFr. Tissues were rinsed in Sorenson's phosphate buffer, immersed in 20% sucrose in buffer and then snap frozen in isopentane. Corneas were then embedded in OCT medium and 15 micro m cryostat sections were created. Presence of OGF was determined by using a polyclonal antibody to [Met5]enkephalin and assessing immunoreactivity. OGFr presence was determined by using a previously characterized rabbit polyclonal antibody to the receptor.
  
  
  RESULTS
  OGF and OGFr were identified in large quantities in the corneal epithelium of all three species.
  
  
  CONCLUSIONS
  Opioid growth factor and its specific receptor are present in the corneal epithelium of normal cats, dogs and horses. OGF is present in the cornea of many species and its presence is theorized to inhibit healing of injured tissue.
authors.affiliation: Large Animal Clinical Sciences, University of Florida, College of Veterinary Medicine, PO Box 100136, Gainesville 32610-0136, USA. robertsons@mail.vetmed.ufl.edu
authors.forename: Sheilah A
authors.initials: SA
authors.lastname: Robertson
authors.forename: Stacy E
authors.initials: SE
authors.lastname: Andrew
mesh_terms: D000818:Animals; D002415:Cats / Q000378:metabolism*; D003315:Cornea / Q000378:metabolism*; D004285:Dogs / Q000378:metabolism*; D004744:Enkephalin, Methionine / Q000378:metabolism*; D006736:Horses / Q000378:metabolism*; D007150:Immunohistochemistry / Q000662:veterinary; D011957:Receptors, Opioid / Q000378:metabolism*
chemical_list: D011957:Receptors, Opioid; C033593:methionine-enkephalin receptor; D004744:Enkephalin, Methionine