title: Application of C1-esterase inhibitor during reperfusion of ischemic myocardium: dose-related beneficial versus detrimental effects.
abstract: BACKGROUND
  Complement activation during reperfusion of ischemic myocardium augments myocardial injury, and complement inhibition with C1-esterase inhibitor (C1-INH) at the time of reperfusion exerts marked cardioprotective effects in experimental studies. Application of C1-INH in newborns, however, was recently reported to have dangerous and even lethal side effects. This study addresses the essential role of dosage in studies using C1-INH.
  
  
  RESULTS
  Cardioprotection by C1-INH was examined in a pig model with 60 minutes of coronary occlusion followed by 120 minutes of reperfusion. C1-INH was administered intravenously 5 to 10 minutes before coronary reperfusion without heparin at a dose of 40, 100, and 200 IU/kg body wt. Compared with the NaCl controls, C1-INH 40 IU/kg reduced myocardial injury (44.1+/-13.8% versus 76.7+/-4.6% necrosis of area at risk, P</=0.05) and significantly suppressed local C3a and C5a generation. Myocardial protection was accompanied by reduced plasma concentrations of creatine kinase and troponin T. In contrast, no beneficial effects were observed when 100 IU/kg C1-INH was used. Furthermore, application of 200 IU/kg C1-INH provoked severe side effects and coagulation disorders.
  
  
  CONCLUSIONS
  When applied at the correct dose, C1-INH significantly protects ischemic tissue from reperfusion damage. However, overly high doses (>/=100 IU/kg) of C1-INH will provoke detrimental side effects, probably via its procoagulatory action.
authors.affiliation: 2nd Medical Clinic, Institute for Neurosurgical Pathophysiology, Johannes Gutenberg University, Mainz, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Horstick
authors.forename: O
authors.initials: O
authors.lastname: Berg
authors.forename: A
authors.initials: A
authors.lastname: Heimann
authors.forename: O
authors.initials: O
authors.lastname: Götze
authors.forename: M
authors.initials: M
authors.lastname: Loos
authors.forename: G
authors.initials: G
authors.lastname: Hafner
authors.forename: B
authors.initials: B
authors.lastname: Bierbach
authors.forename: S
authors.initials: S
authors.lastname: Petersen
authors.forename: S
authors.initials: S
authors.lastname: Bhakdi
authors.forename: H
authors.initials: H
authors.lastname: Darius
authors.forename: M
authors.initials: M
authors.lastname: Horstick
authors.forename: J
authors.initials: J
authors.lastname: Meyer
authors.forename: O
authors.initials: O
authors.lastname: Kempski
mesh_terms: D000706:Anaphylatoxins / Q000378:metabolism; D000818:Animals; D001784:Blood Gas Analysis; D002302:Cardiac Output / Q000187:drug effects; D003174:Complement C1 Inactivator Proteins / Q000378:metabolism / Q000494:pharmacology*; D003326:Coronary Circulation / Q000187:drug effects; D003402:Creatine Kinase / Q000097:blood / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006352:Heart Ventricles / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects; D019344:Lactic Acid / Q000097:blood; D008854:Microscopy, Electron; D017202:Myocardial Ischemia / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D009336:Necrosis; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D015427:Reperfusion Injury / Q000209:etiology / Q000517:prevention & control*; D013552:Swine; D020107:Troponin T / Q000097:blood / Q000187:drug effects
chemical_list: D000706:Anaphylatoxins; D003174:Complement C1 Inactivator Proteins; D020107:Troponin T; D019344:Lactic Acid; D003402:Creatine Kinase; D010100:Oxygen