Interleukin-1 beta of Red nucleus involved in the development of allodynia in spared nerve injury rats.

Previous studies have indicated that interleukin-1 beta (IL-1 beta) is involved not only in immune modulation, but also in the modulation of pain in both the peripheral and central nervous systems. The current study investigated the expression of IL-1 beta in the brain of rats with spared nerve injury (SNI), using immunohistochemical technique. The results showed that immunoreactive-like IL-1 beta protein was significantly elevated in the Red nucleus (RN) 2 weeks after SNI. To further study the function of IL-1 beta in RN, different doses of IL-1 beta neutralizing antibody (10, 1.0 and 0.1 ng) were microinjected into the RN contralateral to the nerve injury side of neuropathic rats. The results indicated that the higher doses of anti-IL-1 beta antibody (10 and 1.0 ng) significantly attenuated the mechanical allodynia of neuropathic rats. However, administration of 0.1 ng anti-IL-1 beta antibody did not show anti-allodynia effect. These results suggest that IL-1 beta of RN is involved in the development of neuropathic pain in SNI rats.