title: Myocilin protein levels in the aqueous humor of the glaucomas in selected canine breeds.
abstract: OBJECTIVE
  To compare aqueous humor myocilin protein levels in dogs with the primary glaucomas to those with the secondary glaucomas, primary cataracts, and diabetic cataracts.
  
  
  METHODS
  Four groups were selected, based on diagnosis by the attending veterinary ophthalmologists and included: primary glaucoma (primary open-angle glaucoma (POAG) and primary closed angle glaucoma (PCAG); n = 155); secondary glaucoma (n = 94); primary (presumed inherited) cataract (n = 142), and diabetic cataract (n = 83). A total of 474 samples (187 males, 263 females, 24 unreported) with average ages of 117 months for the males and 101 months for the females were analyzed. Myocilin protein was measured using the Coomassie staining and Western blot methods relative to a myocilin control.
  
  
  RESULTS
  Differences were seen between nonglaucomatous (cataractous) and glaucomatous dogs with myocilin levels in glaucomatous eyes being many times higher than those in the cataractous dogs. Primary glaucomatous dogs were found to have an aqueous humor myocilin protein level of 17.30 +/- 1.03 units. Secondary glaucomas had the highest level of myocilin in the aqueous humor with 19.27 +/- 1.41 units. Diabetic cataractous dogs had the lowest levels of myocilin reported with 6.60 +/- 0.88 (mean +/- SEM) units. Normal (cataractous) dogs had a myocilin level in the aqueous humor of 8.05 +/- 0.86 units.
  
  
  CONCLUSIONS
  Aqueous humor protein levels were elevated, relative to the myocilin control, in both the primary and secondary glaucoma groups compared to the cataract and diabetic cataract groups. Like in the Beagle POAG, aqueous humor myocilin protein levels are increased. Further studies are indicated to investigate the exact role of the aqueous humor myocilin protein in the genesis in increased IOP in these primary glaucomatous breeds.
authors.affiliation: Department of Small Animal Clinical Sciences and Gwathmey-Adams Laboratory for Vision Research, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: E O
authors.initials: EO
authors.lastname: MacKay
authors.forename: M E
authors.initials: ME
authors.lastname: Kallberg
authors.forename: K P
authors.initials: KP
authors.lastname: Barrie
authors.forename: W
authors.initials: W
authors.lastname: Miller
authors.forename: J S
authors.initials: JS
authors.lastname: Sapienza
authors.forename: H
authors.initials: H
authors.lastname: Denis
authors.forename: F J
authors.initials: FJ
authors.lastname: Ollivier
authors.forename: C
authors.initials: C
authors.lastname: Plummer
authors.forename: T
authors.initials: T
authors.lastname: Rinkoski
authors.forename: N
authors.initials: N
authors.lastname: Scotty
authors.forename: K N
authors.initials: KN
authors.lastname: Gelatt
mesh_terms: D000818:Animals; D001082:Aqueous Humor / Q000378:metabolism*; D016022:Case-Control Studies; D002386:Cataract / Q000235:genetics / Q000378:metabolism / Q000662:veterinary*; D003598:Cytoskeletal Proteins / Q000032:analysis / Q000378:metabolism*; D004283:Dog Diseases / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D005136:Eye Proteins / Q000032:analysis / Q000378:metabolism*; D005260:Female; D020022:Genetic Predisposition to Disease; D005901:Glaucoma / Q000235:genetics / Q000378:metabolism / Q000662:veterinary*; D005902:Glaucoma, Open-Angle / Q000378:metabolism / Q000662:veterinary; D006023:Glycoproteins / Q000032:analysis / Q000378:metabolism*; D008297:Male; D000099179:Myocilin
chemical_list: D003598:Cytoskeletal Proteins; D005136:Eye Proteins; D006023:Glycoproteins; D000099179:Myocilin