COBALT CHLORIDE IMPROVES THE MECHANICAL AND ENERGETIC PERFORMANCE OF ISLOTED RAT HEARTS EXPOSED TO ISCHEMIA-REPERFUSION

VIGÓN RUFFA, FACUNDO; BANCALARI, IGNACIO; FERNANDEZ VIVANCO, MERCEDES; LALLOPIZZO,CARLA; TORASSO, NICOLÁS; CASTILLA, ROCÍO; BONAZZOLA, PATRICIA

Mendoza

Congreso; Annual meeting of the ISHR-Latin American Section held in conjunction with the Argentiniean Society for Arterial Hypertension (SAHA; 2017

ISHR-Latin American Section and Argentiniean Society for Arterial Hypertension (SAHA

It is known that he damage inducedby Ischemia-reperfusion (I/R) was reduced by ischemic postconditionning (IP).CoCl2 (Co) possess properties to function as IP element, as it cantrigger transcriptional changes which resemble the response to a hypoxic eventin normoxic conditions. So, our aim was to evaluate Co as IP therapeutic tool.Mechanic and energetic parameters of isolated and arterially perfused (6ml/min/g) rat heart ventricles were simultaneously analyzed in a model of I/R (30min I-45 min R) at 37 °C in which 0.23 mM Co wasintroduced during R. Total heat released (Ht), developed pressure (P) anddiastolic pressure (LVEDP) were measured. The economy (Eco) was calculated as P/Ht.The presence of Co unchanged LVEDP, but increased P reaching amaximum at 20 min of R (51.8±6.3 vs. 21.2±4.8% of pre-I values), followed by a decreaseto 37.0±4.2% at the end of R. This decrease was avoided when Co was removed at25 min of R, then P reached 57.8±7.9% of pre-I value at the end of R. Htincreased during all R period while Eco only increased between 15 and 25 min ofR (65.0±8.4 vs 39.8±6.4% of pre-I values) which indicates that the muscle ismore efficient when Co was present. Furthermore, the number of arrhythmiasmeasured at 10-20 min of R decreased with Co (5-83 vs.195-566). To indirectly testthe possibility that SR Ca load in the presence of Co was altered, thecontracture evoked by caffeine low sodium media added at 20 min of R wasevaluated. The area under the curve of contracture was unchanged but the rate ofcontracture tension relaxation was higher with Co (-0.34±0.07 vs.-0.06±0.09mmHg/min). Results indicate that the presence of Co in R induces cardioprotectionthat maybe due to its calcium blocker role which avoids, at least in part, the SRand/or mitochondria Ca -overload, producing a better Ca handling. The use of Coat least during the first 20 min of R after an I would have clinical relevance asa cardioprotective tool.