title: Role of matrix metalloproteinase-2 in the cardioprotective effect of ischaemic postconditioning.
abstract: The activation of matrix metalloproteinases (MMPs) contributes to myocardial injury at the onset of reperfusion; however, their role in ischaemic postconditioning is unknown. The aim of the present study was to examine the effects of ischaemic postconditioning on MMP activity in isolated rabbit hearts. The isolated rabbit hearts were subjected to 30 min of global ischaemia followed by 180 min of reperfusion (I/R group; n = 8). In the ischaemic postconditioning group (n = 8), a postconditioning protocol was performed (2 cycles of 30 s reperfusion-ischaemia). In other experiments, we added doxycycline, an MMP inhibitor, at 25 (n = 7) or 50 micromol l(1) (n = 8) during the first 2 min of reperfusion. Coronary effluent and left ventricular tissue were collected during pre-ischaemic conditions and at different times during the reperfusion period to measure MMP-2 activity and cardiac protein nitration. We evaluated ventricular function and infarct size. In the I/R group, infarct size was 32.1 +/- 5.2%; Postcon reduced infarct size to 9.5 +/- 3.8% (P < 0.05) and inhibited MMP-2 activity during reperfusion. The administration of doxycycline at 50 micromol l(1) inhibited MMP-2 activity and cardiac protein nitration and reduced the infarct size to 9.7 +/- 2.8% (P < 0.05). A lower dose of doxycycline (25 micromol l(1)) failed to inhibit MMP-2 activity and did not modify the infarct size. Our results strongly suggest that ischaemic postconditioning may exert part of its cardioprotective effects through the inhibition of MMP-2 activity.
authors.affiliation: Institute of Cardiovascular Physiopathology, Department of Pathology, University of Buenos Aires, JE Uriburu 950, 2nd floor, C1114AAD, Buenos Aires, Argentina.
authors.forename: Martín
authors.initials: M
authors.lastname: Donato
authors.forename: Verónica
authors.initials: V
authors.lastname: D'Annunzio
authors.forename: Bruno
authors.initials: B
authors.lastname: Buchholz
authors.forename: Verónica
authors.initials: V
authors.lastname: Miksztowicz
authors.forename: Cristina Lorenzo
authors.initials: CL
authors.lastname: Carrión
authors.forename: Laura B
authors.initials: LB
authors.lastname: Valdez
authors.forename: Tamara
authors.initials: T
authors.lastname: Zaobornyj
authors.forename: Laura
authors.initials: L
authors.lastname: Schreier
authors.forename: Regina
authors.initials: R
authors.lastname: Wikinski
authors.forename: Alberto
authors.initials: A
authors.lastname: Boveris
authors.forename: Gabriela
authors.initials: G
authors.lastname: Berg
authors.forename: Ricardo J
authors.initials: RJ
authors.lastname: Gelpi
mesh_terms: D000818:Animals; D003326:Coronary Circulation; D004789:Enzyme Activation; D006352:Heart Ventricles / Q000503:physiopathology*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D015428:Myocardial Reperfusion Injury / Q000150:complications / Q000503:physiopathology*; D011817:Rabbits; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000503:physiopathology*
chemical_list: D020778:Matrix Metalloproteinase 2