Abstract

Opioids reduce injury from myocardial ischemia-reperfusion in humans. In experimental models, this mechanism involves GSK3ß inhibition. HSP90 regulates mitochondrial protein import, with GSK3ß inhibition increasing HSP90 mitochondrial content. Therefore, we determined whether morphine-induced cardioprotection is mediated by HSP90 and if the protective effect is downstream of GSK3ß inhibition. Male Sprague-Dawley rats, aged 8-10 weeks, were subjected to an in vivo myocardial ischemia-reperfusion injury protocol involving 30 minutes of ischemia followed by 2 hours of reperfusion. Hemodynamics were continually monitored and myocardial infarct size determined. Rats received morphine (0.3?mg/kg), the GSK3ß inhibitor, SB216763 (0.6?mg/kg), or saline, 10 minutes prior to ischemia. Some rats received selective HSP90 inhibitors, radicicol (0.3?mg/kg), or deoxyspergualin (DSG, 0.6?mg/kg) alone or 5 minutes prior to morphine or SB216763. Morphine reduced myocardial infarct size when compared to control (42 ± 2% versus 60 ± 1%). This protection was abolished by prior treatment of radicicol or DSG (59 ± 1%, 56 ± 2%). GSK3ß inhibition also reduced myocardial infarct size (41 ± 2%) with HSP90 inhibition by radicicol or DSG partially inhibiting SB216763-induced infarct size reduction (54 ± 3%, 47 ± 1%, resp.). These data suggest that opioid-induced cardioprotection is mediated by HSP90. Part of this protection afforded by HSP90 is downstream of GSK3ß, potentially via the HSP-TOM mitochondrial import pathway.

View details for DOI 10.1155/2015/129612

View details for PubMedID 26413502

View details for PubMedCentralID PMC4564588