Effects of deltamethrin on nitric oxide synthase and poly(ADP-ribose) polymerase in rat brain

The effects of deltamethrin on the activities of nitric oxide synthase (NOS ) and poly(ADP-ribose) polymerase (PARP) and the protein expression of neur onal NOS (nNOS) and PARP in rat brain were investigated in the: present stu dy. The activity of NOS was significantly increased in cortex and hippocamp us at 5 h after deltamethrin treatment, and maintained at an increased leve l at 24 h. The activity of PARP was also elevated at the same time points i n the same brain regions of treated rats. By immunohistochemical analysis, it was demonstrated that the nNOS-immunoreactive cells were markedly increa sed at 24 h after treatment in the cortex and hippocampus, whereas few nNOS -immunoreactive cells were observed in the same brain regions of control an d treated rats at 5 h after treatment. The immunoreactivity for PARP was al so increased in the same brain regions, showing the similar time course of the induction of nNOS by deltamethrin. These results indicate that deltamet hrin increases the activities of NOS and PARP and initiates the protein exp ression of nNOS and PARP, suggesting that NOS and PARP might play important roles in neurotoxicity of deltamethrin. (C) 1999 Elsevier Science B.V. All rights reserved.