Effect of interleukin-1 beta on the elevation of cytoplasmic free calcium of the cultured hippocampal neurons induced by L-glutamate.

To investigate the intracellular mechanism that interleukin-1 beta (IL-1 beta) facilitates epileptic seizure and neuronal damage, the effect of IL-1 beta alone or IL-1 beta plus glutamate (Glu) on the intracellular free calcium ([Ca2+]i) of single cultured hippocampal neuron was examined by using EPC-9 light-electricity measurement system. The results showed that IL-1 beta of different concentrations (5 x 10(3) U/L, 10 x 10(3) U/L, 20 x 10(3) U/L, 30 x 10(3) U/L, 50 x 10(3) U/L, 100 x 10(3) U/L) failed to affect the neuronal [Ca2+]i, but IL-1 beta could facilitate the augmentation of neuronal [Ca2+]i induced by Glu in a dose-dependent pattern. MK-801 inhibited the effect of Glu on [Ca2+]i, and also inhibited the effect of IL-1 beta on [Ca2+]i induced by Glu, while verapamil did not influence the effect of Glu or IL-1 beta. It is concluded that IL-1 beta, as a neuromodulator, can facilitate the activation of NMDA receptor by Glu, induce the increase of intracellular calcium, which enhances the excitement of neuron.