title: Detection of lysozyme in llama, sheep, and cattle tears.
abstract: OBJECTIVE
  To determine whether the tears of llamas, sheep, and cattle contain lysozyme and compare lysozyme concentrations in tears among these species.
  
  
  METHODS
  40 llamas, 5 sheep, and 36 cattle.
  
  
  METHODS
  Electrophoresis, western blot immunoassay for lysozyme, a spectrophotometric assay to detect tear lysozyme by its ability to lyse a suspension of Micrococcus lysodeiticus, and a microtiter plate colorometric assay were performed.
  
  
  RESULTS
  A 13.6-kd protein band was detected by use of electrophoresis and western blot immunoassay in llama and sheep tears but not cattle tears. Results of spectrophotometric assay suggested that llama and sheep tears had high concentrations of lysozyme, whereas cattle tears had low concentrations. Results of the microtiter plate colorometric assay suggested that llama tears had high concentrations of lysozyme, whereas concentrations in sheep and cattle tears were lower.
  
  
  CONCLUSIONS
  Lysozyme concentrations in tears may vary among species and this variability may contribute to differing susceptibilities to ocular diseases such as infectious keratoconjunctivitis.
authors.affiliation: Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47906, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Gionfriddo
authors.forename: H
authors.initials: H
authors.lastname: Davidson
authors.forename: E K
authors.initials: EK
authors.lastname: Asem
authors.forename: S G
authors.initials: SG
authors.lastname: Krohne
mesh_terms: D000818:Animals; D015153:Blotting, Western / Q000662:veterinary; D002161:Camelids, New World / Q000378:metabolism*; D002417:Cattle / Q000378:metabolism*; D003124:Colorimetry / Q000662:veterinary; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D005136:Eye Proteins / Q000737:chemistry*; D009113:Muramidase / Q000032:analysis*; D012756:Sheep / Q000378:metabolism*; D013666:Tears / Q000737:chemistry*
chemical_list: D005136:Eye Proteins; C042434:tear proteins; D009113:Muramidase