Changes in nitric oxide and expression of nitric oxide synthase in spinal cord after acute traumatic injury in rats.
The aim of this study was to observe the time course of NO production and NOS expression in the spinal cord following acute traumatic injury. Rat spinal cord was injured by extradural static weight-compression, which resulted in an incomplete transverse spinal cord lesion with paralysis of the lower extremities. Using this model, measurement of NO by microdialysis and Griess reaction and histological and immunohistochemical examinations using polyclonal antibodies to nNOS and iNOS were performed from immediately to 14 days after injury. In injured cord, the amount of NO markedly increased immediately after injury and gradually decreased between 1 and 12 h after injury. A second wave of increase in NO level was observed at 24 h and 3 days after injury. Histologically, hematomas and necrotic changes were observed after injury and demyelination of nerve fibers increased with time in the compressed segment. Immunohistochemically, the number of cells with expression of nNOS was increased immediately to 12 h after injury. Expression of iNOS was observed from 12 h to 3 days after injury. These findings suggested that the initial maximal increase of NO production might be caused mainly by nNOS and that the second wave of increase in NO might be due mainly to iNOS.
Nakahara
Shinji
S
Department of Orthopaedic Surgery, Faculty of Medicine, Kagoshima University, Kagoshima, Japan.
Yone
Kazunori
K
Setoguchi
Takao
T
Yamaura
Ichiro
I
Arishima
Yoshiya
Y
Yoshino
Shinji
S
Komiya
Setsuro
S
D000818:Animals; D008297:Male; D009569:Nitric Oxide / Q000032:analysis / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000096:biosynthesis*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D013119:Spinal Cord Injuries / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology
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; C496322:Nos1 protein, rat; C496318:Nos2 protein, rat; C496316:Nos3 protein, rat