Intranasal administration of human IL-6 increases the severity of chemically induced seizures in rats.

Here we study the role of a pleiotropic pro-inflammatory cytokine, interleukin-6 (IL-6), in epilepsy. To examine this problem, we used human recombinant IL-6 applied intranasally (400 ng/40 microl) to rats 1h before seizures induced by systemic injection of pentylenenetrazole (PTZ, 75 mg/kg). Overall, compared to the saline-treated control animals (n = 11 in each group), IL-6-treated rats demonstrated elevated levels of IL-6 in the frontal lobe (measured by ELISA) and increased severity of PTZ-induced seizures (shorter latency, longer duration and higher mortality). Our findings show that IL-6 plays a pro-convulsant role in the brain and suggest that the IL-6 system may be a novel target for the development of anticonvulsant drugs.