Interleukin-1 and nociception in the rat.

It has recently become accepted that several cytokines may affect peripheral and central nervous system functions. Consistently with these findings, accumulating evidence points toward an important role for interleukin- in the modulation of nociceptive information. Here we review the observations collected after the administration of this cytokine by intracerebroventricular, intrathecal or peripheral route in rats. Taken together, these data suggest that IL-1 can differently affect pain responsivity depending on the dose and the site of action, and clearly demonstrate that this immune factor is deeply involved in the modulation of neuronal functions.