Neuronal nitric oxide synthase is the dominant nitric oxide supplier for the survival of dorsal root ganglia after peripheral nerve axotomy.
This study was designed to determine whether nitric oxide supply may be a major factor in the survival of dorsal root ganglia in a sciatic nerve injury model. Wild-type (WT) mice were compared with knockout (KO) mice lacking neuronal nitric oxide synthase (nNOS) or endothelial (eNOS). The NO-generating capacities were analysed by NOS immunohistochemistry and NADPH-diaphorase staining 1, 2, 6, and 12 weeks after nerve transection. The occurrence and morphological type of neuronal death were determined by TUNEL reaction and ultrastructural examination. Cell loss following nerve section, whist dependent on the availability of NO, as shown by its marked elevation in nNOS KO mice, did not correlate well with nNOS expression in WT animals. Whereas a lack of eNOS was tolerated, deficiency of nNOS led to an enhanced cell loss. The results suggest a crucial role of NO supply after transection of peripheral nerves with a particular significance of the nNOS isoform.
Keilhoff
Gerburg
G
Institute of Medical Neurobiology, Medical Faculty, Otto-von-Guericke University, Leipziger Strasse 44, D-39120, Magdeburg, Germany. gerburg.keilhoff@medizin.uni-magdeburg.de
Fansa
Hisham
H
Wolf
Gerald
G
D000818:Animals; D019771:Axotomy; D002470:Cell Survival / Q000502:physiology; D005727:Ganglia, Spinal / Q000737:chemistry / Q000166:cytology* / Q000201:enzymology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D010525:Peripheral Nerves / Q000737:chemistry / Q000166:cytology / Q000201:enzymology*
D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496321:Nos1 protein, mouse; C496315:Nos3 protein, mouse