XDH and infarction: Peroxynitrite, the reaction product of nitric oxide and superoxide, has been shown to activate activator protein-1 [16], which in turn can activate the NGF promoter and enhance the transcripts of NGF. These results extend our previous findings that antioxidation caused by the administration of N-acetylcysteine or xanthine oxidase inhibitors can attenuate sympathetic hyperinnervation after infarction [8,9].