Objective: To investigate the change in glycogen synthase kinase-3β (GSK-3β) in spinal cord neurons in rats with incisional pain (IP)-remifentanil-induced hyperalgesia.
Methods: 32 SD male rats (240 - 260 g) were randomly divided into 4 groups (n = 8 each): group R, group I, group R + I and group C. IP was established as Brennan's description. Paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were measured 24h before anesthesia and 2, 6, 24, 48 h after anesthesia. The rats were sacrificed after the last threshold measurement. The expressions of GSK-3β mRNA in rats' spinal cord neurons were determined by real-time PCR. The expressions of GSK-3β and pGSK-3β in rats' spinal cord neurons were determined by Western blot.
Results: Remifentanil-induced hyperalgesia developed in group R, I and R + I. The expression of GSK-3β mRNA and the expression of GSK-3β in rats' spinal cord neurons were highest in group R + I. In addition, the ratio of pGSK-3β/GSK-3β was smallest in group R + I.
Conclusion: These data indicate that the increased GSK-3β activity in rats spinal cord neurons is involved in remifentanil-induced hyperalgesia.