Neuropediatrics 2006; 37 - THP6
DOI: 10.1055/s-2006-945829

THE EFFECT OF IL-6 ON HYPERTHERMIA-INDUCED SEIZURES IN DEVELOPING RATS

M Fukuda 1, C Shinonaga 1, Y Suzuki 2, K Kida 1, T Morimoto 3
  • 1Department of Pediatrics, Ehime University School of Medicine, Toon-city, Ehime, Japan
  • 2Strong Epilepsy Center, University of Rochester Medical Center, Rochester, NY, United States
  • 3Ehime Disabled Children's Hospital, Matsuyama, Ehime, Japan

Objectives: Previous studies indicated that several cytokines influenced the seizure propensity in convulsive disorders. We studied the role of one inflammatory cytokine, interleukin-6 (IL-6), in hyperthermia-induced seizures in developing rats.

Methods: Twenty-four male Lewis rats (23–28 days old) were divided into three groups (n=8 / IL-6 50ng, IL-6 500ng and saline control groups). Two holes were made in the skull over the right frontal and occipital cortex, and silver screw electrodes for electroencephalography (EEG) were placed in them. Another hole was made over the left parietal cortex, and a wire-thermometer for brain temperature measurements was inserted. We applied human recombinant IL-6 intra-nasally to developing rats 1h before seizures induced by moist heated air (50degrees C). The seizure threshold was defined as the latency from hyperthermia onset until the appearance of continuous seizure discharges on EEG, and the seizure duration was defined as the duration of continuous spike-and-wave discharges on EEG.

Results: The seizure threshold for the IL-6 (500ng) group, 360(256–360) (median, range) s, was significantly higher than that for the control one, 249(121–360), (P<0.05), and the seizure duration for the IL-6 (500ng) group, 0(0–20)s, was significantly shorter than that for the control one, 33(0–76), (P<0.025). Also, the brain temperature at the onset of seizures for the IL-6 (500ng) group, 45.5(44.7–46.2) degrees C, was higher than that for the control one, 44.3(39.8–45.4), (P<0.01).

Conclusion: These results indicate that IL-6 plays an anti-convulsant role in hyperthermia-induced seizures in developing rats. Also, it is suggested that IL-6 has a neuro-protective effect on the developing brain.