title: [Activity of cathepsin a in subretinal fluid in primary retinal detachment].
abstract: OBJECTIVE
  To evaluate cathepsin A activity in the subretinal fluid in the primary retinal detachment.
  
  
  METHODS
  The studies were performed on subretinal fluids taken from 38 patients operated for the primary retinal detachment. Duration of the detachment was contained between 1 week and 6 months. Cathepsin A activity was determined by the ninhydrin method with synthetic substrate (N-Cbz-Phe-Ala) at its optimum pH 5.0.
  
  
  RESULTS
  Cathepsin A activity was demonstrated in all investigated fluids. The highest activity was found at about the 4th week of the detachment and then it decreased. No differences of enzyme activity according to sex and refraction error were found.
  
  
  CONCLUSIONS
  The increasing proteolytic activity in the subretinal fluid could be an important factor in gradual degrading of the structure and function of the detached retina, because cathepsins are involved in digestion of outer segment proteins of rods and cones and degradation of mucopolysaccharide interphotoreceptor matrix. Retinal degradation during detachment is probably induced by both insufficient nutrition and the effect of increasing lysosomal enzymes.
authors.affiliation: Katedry i Kliniki Okulistyki AM w Białymstoku.
authors.forename: I
authors.initials: I
authors.lastname: Obuchowska
authors.forename: A
authors.initials: A
authors.lastname: Stankiewicz
authors.forename: Z
authors.initials: Z
authors.lastname: Mariak
authors.forename: E
authors.initials: E
authors.lastname: Proniewska-Skretek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D001826:Body Fluids / Q000737:chemistry / Q000201:enzymology*; D002268:Carboxypeptidases / Q000378:metabolism*; D043402:Cathepsin A; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D012163:Retinal Detachment / Q000201:enzymology*
chemical_list: D015415:Biomarkers; D002268:Carboxypeptidases; C468629:CTSA protein, human; D043402:Cathepsin A