title: Effect of alpha-chymotrypsin on breaking strength and ultrastructural morphology of canine ciliary zonules.
abstract: OBJECTIVE
  To determine the effect of alpha-chymotrypsin treatment on breaking strength and ultrastructural morphology of canine ciliary zonules.
  
  
  METHODS
  Eyes from young random-source dogs from an animal shelter.
  
  
  METHODS
  Eyes were obtained immediately after euthanasia of dogs. The enzyme alpha-chymotrypsin was applied to the ciliary zonules of 1 eye of each dog; the other eye was treated with saline solution as a control. The breaking strength of ciliary zonules was measured, using a linear actuator and force transducer. The lenses and ciliary bodies were then analyzed by scanning and transmission electron microscopy.
  
  
  RESULTS
  alpha-Chymotrypsin reduced the breaking strength of ciliary zonules by a mean +/- SD 44 (+/- 20)%, compared with that for saline-treated control eyes. Increasing the volume of enzyme further decreased the breaking strength of the zonules. Differences in the appearance of the ciliary body by electron microscopy were not apparent between enzyme- and saline-treated specimens.
  
  
  CONCLUSIONS
  Application of alpha-chymotrypsin to enucleated canine eyes at a concentration used in people significantly reduces the breaking strength of canine ciliary zonules without any apparent damage to the ciliary body. alpha-Chymotrypsin may be useful in the removal of subluxated canine lenses and in removal of cataractous lenses in young dogs, in which phacoemulsification often results in appreciable post operative capsular opacification.
authors.affiliation: Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri-Columbia 65211, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Halenda
authors.forename: M P
authors.initials: MP
authors.lastname: Nasisse
authors.forename: M J
authors.initials: MJ
authors.lastname: Dykstra
mesh_terms: D000818:Animals; D002918:Chymotrypsin / Q000494:pharmacology*; D002924:Ciliary Body / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure*; D004285:Dogs; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D013718:Tensile Strength
chemical_list: D002918:Chymotrypsin