Paraquat--a superoxide generator--kills neurons in the rat spinal cord.

Microdialysis was used to administer paraquat into the spinal cord of the anesthetized rat to determine the effects of the in vivo generation of the superoxide anion (O2.-) on neurons. Exposure to paraquat caused blockage of axonal conduction, destruction of the cell bodies of neurons, and a general release of amino acids. Thus, paraquat is quite harmful to neuronal tissue. Similarities between paraquat-induced damage and that previously observed from the hydroxyl radical are consistent with paraquat, causing damage by generation of reactive oxygen species and the widespread belief that generation of O2.- initiates the formation of destructive reactive oxygen species in a wide variety of traumas and other disorders.