Abstract
Paraquat has previously been shown to reduce the viability of rat C6 glioma cells, suggesting that this drug may be toxic to normal glial cells. However, there is no direct evidence for the cytotoxic effect of paraquat on glial cell in vivo. To investigate the toxic effect of paraquat, the damage to hippocampal neurons and astrocytes in paraquat-poisoned rat brain was immunohistochemically examined using microtubule associate protein-2 (MAP-2) and glial fibrillary acidic protein (GFAP) as a histological marker. Paraquat poisoning reduced the number of astrocytes in rat hippocampus in a concentration-dependent manner. In addition, paraquat caused the damage to hippocampal neurons at relatively lower doses (25 and 50mg/kg), and this neuronal damage was unexpectedly less pronounced at a higher dose (100mg/kg). These findings indicate that paraquat is toxic to astrocytes in vivo, and furthermore suggests that the toxic effect of paraquat on glial cells may be different from that on neuronal cells in the rat brain.
