the modulatory effect of buprenorphine on analgesia and alteration in expression of bdnf and creb genes in rat spinal cord due to intraperitoneal injection of methamphetamine

Background: methamphetamine is a commonly abused drug, and its neurotoxic effects have increased in recent years. there is growing evidence that buprenorphine, a widely used drug for pain management, reduces the harmful effects of addiction and is effective in treating opioid dependence. objectives: this study aimed to investigate the interaction between methamphetamine and buprenorphine on analgesia and the expression of bdnf and creb genes in the spinal cords of rats. methods: in this study, 56 male wistar rats (200 ± 50 g) were randomly assigned to eight groups: control, sham, methamphetamine, two buprenorphine groups, two methamphetamine + buprenorphine groups, and a deprivation group. a one-way anova test was used to analyze the data. results: intraperitoneal injection of methamphetamine (10 mg/kg) induced analgesia (p < 0.05) and increased creb gene expression in the lumbar spinal cord (p < 0.01), whereas buprenorphine alone (6 and 10 mg/kg) did not induce significant analgesia or alter bdnf gene expression in the spinal cord. pharmacological interactions revealed that buprenorphine (6 and 10 mg/kg, i.p.) enhanced the analgesic effect of methamphetamine. additionally, while the lower dose of buprenorphine reduced methamphetamine's effect on creb gene expression (p < 0.05), the higher dose potentiated the effect of methamphetamine on bdnf gene expression (p < 0.01) without significantly affecting creb gene expression. conclusions: the findings suggest that buprenorphine may enhance the analgesic effects of acute methamphetamine administration and modulate gene expression in the lumbar spinal cord of male wistar rats.