Spinal A₃ adenosine receptor activation acutely restores morphine antinociception in opioid tolerant male rats.

ABSTRACT: Opioids are potent analgesics, but their pain-relieving effects diminish with repeated use. The reduction in analgesic potency is a hallmark of opioid analgesic tolerance, which hampers opioid pain therapy. In the central nervous system, opioid analgesia is critically modulated by adenosine, a purine nucleoside implicated in the beneficial and detrimental actions of opioid medications. Here, we focus on the A₃ adenosine receptor (A₃ AR) in opioid analgesic tolerance. Intrathecal administration of the A₃ AR agonist MRS5698 with daily systemic morphine in male rats attenuated the reduction in morphine antinociception over 7 days. In rats with established morphine tolerance, intrathecal MRS5698 partially restored the antinociceptive effects of morphine. Howeve

SUBMITTER: Leduc-Pessah H 

PROVIDER: S-EPMC9365530 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature