title: Chymase and angiotensin converting enzyme activities in a hamster model of glaucoma filtering surgery.
abstract: OBJECTIVE
  Two pathways for the formation of angiotensin II (Ang II) in local tissues are known to exist, one involving angiotensin-converting enzyme (ACE), and the other in which chymase plays a role. It has been shown that chymase activity is present in monkey, dog, and hamster eyes. Because chymase activates various cytokines by increasing Ang II formation, thereby promoting the production of extracellular matrix, the role of Ang II in wound healing has attracted much interest. In this work, we created sclerocorneal wounds in hamster eyes and measured the levels of ACE and chymase activities in the eye during the wound healing process.
  
  
  METHODS
  Sclerocorneal wounds were made at 6 locations on the corneal limbus of one eye in each of 36 hamsters. Using the contralateral eyes as controls, we measured levels of chymase and ACE activities in the overall eye at 3, 7, and 21 days postoperatively. Histopathological evaluations of the sclerocorneal wounds in the treated eyes were also carried out for samples stained with toluidine blue.
  
  
  RESULTS
  Chymase activity in the treated eyes tended to be higher than that in the control at 21 days. ACE activity in the treated eyes was significantly higher than that in the control at 3, 7, and 21 days postoperatively. Histopathological examination revealed increased mast cells in the subconjunctival tissue and around the tunnel opening in the sclerocornea.
  
  
  CONCLUSIONS
  These findings show that not only ACE but also chymase contributes to the formation of Ang II in the healing of sclerocorneal wounds in hamster eyes. This leads to the suggestion that ACE inhibitors or chymase inhibitors could potentially inhibit scarring in glaucoma filtering surgery.
authors.affiliation: Department of Ophthalmology, Osaka Medical College, Osaka, Japan. opt032@poh.osaka-med.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sakaguchi
authors.forename: Shinji
authors.initials: S
authors.lastname: Takai
authors.forename: Masato
authors.initials: M
authors.lastname: Sakaguchi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ishihara
authors.forename: Yulin
authors.initials: Y
authors.lastname: Yao
authors.forename: Mizuo
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Tsunehiko
authors.initials: T
authors.lastname: Ikeda
mesh_terms: D000818:Animals; D053818:Chymases; D006224:Cricetinae; D005123:Eye / Q000473:pathology; D018463:Filtering Surgery; D005901:Glaucoma / Q000201:enzymology* / Q000473:pathology / Q000601:surgery*; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism*
chemical_list: D007703:Peptidyl-Dipeptidase A; D012697:Serine Endopeptidases; D053818:Chymases