title: TNF-alpha antibodies are as effective as ischemic preconditioning in reducing infarct size in rabbits.
abstract: Pretreatment with tumor necrosis factor-alpha (TNF-alpha) antibodies abolishes myocardial infarct size reduction by late ischemic preconditioning (IP). Whether or not TNF-alpha is also important for myocardial infarct size reduction by classic IP is unknown. Anesthetized rabbits were untreated (group 1, n = 7), classically preconditioned by 5 min left coronary artery occlusion/10 min reperfusion (group 2, n = 6), or pretreated with TNF-alpha antibodies without (group 3, n = 6) or with IP (group 4, n = 6) before undergoing 30 min of occlusion and 180 min of reperfusion. Infarct size in group 1 was 44 +/- 11 (means +/- SD)% of the area at risk. With a comparable area at risk, infarct size was reduced to 13 +/- 7%, 23 +/- 8%, and 19 +/- 12% (all P < 0.05) in groups 2, 3, and 4, respectively. The circulating TNF-alpha concentration was increased during ischemia in group 1 from 752 +/- 403 to 1,542 +/- 482 U/ml (P < 0.05) but remained unchanged in all other groups. Circulating TNF-alpha concentration during ischemia and infarct size correlated in all groups (r = 0.76). IP, TNF-alpha antibodies, and the combined approach reduced infarct size to a comparable extent. Therefore, the question of whether or not TNF-alpha is causally involved in the infarct size reduction by IP in rabbits could not be answered.
authors.affiliation: Institut für Pathophysiologie, Zentrum für Innere Medizin, 45122 Essen, Federal Republic of Germany.
authors.forename: Sergej
authors.initials: S
authors.lastname: Belosjorow
authors.forename: Ines
authors.initials: I
authors.lastname: Bolle
authors.forename: Alexej
authors.initials: A
authors.lastname: Duschin
authors.forename: Gerd
authors.initials: G
authors.lastname: Heusch
authors.forename: Rainer
authors.initials: R
authors.lastname: Schulz
mesh_terms: D000818:Animals; D000906:Antibodies / Q000627:therapeutic use*; D000918:Antibody Specificity; D004195:Disease Models, Animal; D006439:Hemodynamics; D019157:Ischemic Preconditioning, Myocardial; D009203:Myocardial Infarction / Q000473:pathology / Q000517:prevention & control*; D017202:Myocardial Ischemia / Q000503:physiopathology; D015425:Myocardial Reperfusion; D011817:Rabbits; D015996:Survival Rate; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000037:antagonists & inhibitors*
chemical_list: D000906:Antibodies; D014409:Tumor Necrosis Factor-alpha