title: An improved method for extracting myeloperoxidase and determining its activity in the pancreas and lungs during pancreatitis.
abstract: OBJECTIVE
  This study was undertaken to examine the cause of variation in determined values of myeloperoxidase activity from sequestered neutrophils in pancreas and lungs during pancreatitis and to develop a reproducible method for the extraction and measurement of myeloperoxidase in these tissues.
  
  
  METHODS
  We measured myeloperoxidase in pancreatic and lung homogenates at different steps and evaluated the extent of inhibitory activity by measuring enzyme activity in the presence of homogenates from normal lungs and pancreata. To remove inhibitory activity from the homogenates, different methods like heat inactivation, inclusion of catalase inhibitor, and membranous pellet washing were evaluated.
  
  
  RESULTS
  Significant myeloperoxidase inhibitory activity was observed in pancreatic and lung homogenates, which could be effectively removed by the newly developed protocol. In extracts, myeloperoxidase activity can be determined by a spectrophotometric method, which is not only reproducible but is also adaptable for use in a plate reader or an autoanalyzer. Using this method, we studied the pattern of neutrophil sequestration over time in both pancreatic and lung tissue during caerulein-induced pancreatitis.
  
  
  CONCLUSIONS
  Myeloperoxidase inhibition in the pancreas and lungs contributes to the variation observed in measurement of the enzyme.
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Rajinder
authors.initials: R
authors.lastname: Dawra
authors.forename: Yang Sha
authors.initials: YS
authors.lastname: Ku
authors.forename: Rifat
authors.initials: R
authors.lastname: Sharif
authors.forename: Dhara
authors.initials: D
authors.lastname: Dhaulakhandi
authors.forename: Phoebe
authors.initials: P
authors.lastname: Phillips
authors.forename: Vikas
authors.initials: V
authors.lastname: Dudeja
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Saluja
mesh_terms: D000818:Animals; D002108:Ceruletide; D004195:Disease Models, Animal; D008168:Lung / Q000201:enzymology*; D008297:Male; D051379:Mice; D009504:Neutrophils / Q000201:enzymology*; D010179:Pancreas / Q000201:enzymology*; D010195:Pancreatitis / Q000139:chemically induced / Q000201:enzymology*; D009195:Peroxidase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D013053:Spectrophotometry / Q000379:methods*; D013997:Time Factors
chemical_list: D002108:Ceruletide; D009195:Peroxidase