Cyclooxygenase-1 Mediates the Final Stage of Morphine-Induced Delayed Cardioprotection in Concert With Cyclooxygenase-2

Morphine confers delayed cardioprotection via a COX-dependent pathway; COX-2 is essential for the cardioprotection observed in the initial stage (24 h), whereas, in the final stage (48 h), cardioprotection is mediated by COX-1 in concert with COX-2.