抄録
Migration of microglia towards the lesion site plays an important role in the immune system in the brain. Under pathological/physiological conditions such as neuronal axotomy, inflammation, Alzheimer's disease, nociception, cognition, and eating behaviors, several neuropeptides are up-regulated and therefore may affect the brain immune system. In the present study, we investigated the effects of neuropeptides including bradykinin on microglial migration and their signal mechanisms. The bradykinin-induced migration of microglial cells was dependent on activation of protein kinase C, phosphoinositide 3-kinase, extracellular Ca2+ influx due to the reverse mode of Na+/Ca2+ exchanger, and activation of Ca2+-dependent K+ currents (IK(Ca)). On the other hand, ATP, one of the chemoattractants for microglial cells, was dependent on Gi/o but not on IK(Ca). These results suggest that ATP and neuropeptides induce microglial migration with distinct mechanisms and may have different role in their immune system under pathophysiological conditions. [J Physiol Sci. 2008;58 Suppl:S49]
