Changes in G proteins genes expression in rat lumbar spinal cord support the inhibitory effect of chronic pain on the development of tolerance to morphine analgesia

Due to synchronous development of morphine tolerance and changes in expression of Gβ, it may be concluded that the development of tolerance to analgesic effect of morphine is partially mediated by increase in Gβ gene expression. The increase in Gαi/o genes expression produced by chronic pain may facilitate the opioid signaling pathway and compensate for morphine-induced tolerance.