Interleukin-1 beta contributes to the upregulation of kappa opioid receptor mrna in dorsal root ganglia in response to peripheral inflammation

In conclusion, kappa opioid receptor mRNA and protein in dorsal root ganglia are upregulated in response to peripheral inflammation. This effect can be mimicked by a single local injection of interleukin-1 beta, and Freund's complete adjuvant-induced upregulation in kappa opioid receptor mRNA and protein can be prevented by treatment with interleukin-1 receptor antagonist. These data suggest that the peripheral production of the proinflammatory cytokine interleukin-1 beta is a specific inducer of kappa opioid receptor expression in the dorsal root ganglia.