INVESTIGADORES
PORTIANSKY enrique Leo
artículos
Título:
Early ischemic preconditioning diminishes both infarcted area myocardial stunning in isolated rat heart
Autor/es:
MOSCA SM; SALAS MA; PORTIANSKY EL; CINGOLANI HE; MOREYRA AE
Revista:
Experimental and Clinical Cardiology
Editorial:
x
Referencias:
Año: 1999 vol. 4 p. 43 - 48
ISSN:
1205-6626
Resumen:
OBJECTTVE: To establish whether ischemic preconditioning(1 P) exerts its prOtective effect on myocardial function by attenuatingstunning independemly of decreasing infarct size.ANTMALS Al!0 METHOOS: Jsolatcd rat hearts wcrc submittedLO di ffercnt pcriods of global ischemia, at constan! flow. JP was obtainedwith one cycle of 5 mjns of ischemia and JO mins ofrepcrfusion preceeding thc longer ischemic periods. lnfarcl vo lumewas dclincatccl by nitro-bluc tetrawlium (NBT) stain ing anclassesscd by crcatine phosphok.inase (CPK) leakage. Left ventricularcleveloped pressure (L VDP) and the maximal velocity of rise ofleft venrriculár pressurc (+dP/cltmax) wcre uscd as parameters ofcontraclilc function. Correlalions berween myocarclial injury. assessedby CPK rclease or NBT staining, and L VDP were examined. RESULTS: IP significa mly improved recovery of contractilcfunction. After 20. 25 and 35 mins of ischemia, LVDP values at30 mins of reperfusion were 93±4%, 73±2% ancl32± 10%, respective!y in preconditioned hearts versus 53±8%. 33±8% and 8± 1 %.respectively. in nonpreconditioned heru1s. For tbe sru11e ischemicperiods +dP/d tmax values were 95±5%, 74±4% and 35±9%, respectively,in preconditioned hearts versus 51±7%, 35±6% and9± 1%. respectively, in nonpreconditioned hearts. IP decreased infarctsize assessed by both techniques. There was a negati ve correlationbetween infarct volume or CPK leakage, and recovery ofL VDP. The compara ti ve analysis of the s lopes of regression linesshowed that. for the same infarct size assessed by CPK leakage.improvement of Lhe postischemic dysfunction was greater in preconditionedhearts.CONCLUSIONS: In thc isolatcd pcrfusecl rat heart subjected toglobal ischcmia. !P improves recovery of contractilc fu nction as aresult of diminution of infarct size and attenuation of stunning.
