TY - JOUR
T1 - Inducible nitric oxide synthase is an endogenous neuroprotectant after traumatic brain injury in rats and mice
AU - Sinz, Elizabeth H.
AU - Kochanek, Patrick M.
AU - Dixon, C. Edward
AU - Clark, Robert S.B.
AU - Carcillo, Joseph A.
AU - Schiding, Joanne K.
AU - Chen, Minzhi
AU - Wisniewski, Stephen R.
AU - Carlos, Timothy M.
AU - Williams, Debra
AU - DeKosky, Steven T.
AU - Watkins, Simon C.
AU - Marion, Donald W.
AU - Billiar, Timothy R.
PY - 1999/9
Y1 - 1999/9
N2 - Nitric oxide (NO) derived from the inducible isoform of NO synthase (iNOS) is an inflammatory product implicated both in secondary damage and in recovery from brain injury. To address the role of iNOS in experimental traumatic brain injury (TBI), we used 2 paradigms in 2 species. In a model of controlled cortical impact (CCI) with secondary hypoxemia, rats were treated with vehicle or with 1 of 2 iNOS inhibitors (aminoguanidine and L-N- iminoethyl-lysine), administered by Alzet pump for 5 days and 1.5 days after injury, respectively. In a model of CCI, knockout mice lacking the iNOS gene (iNOS(-/-)) were compared with wild-type (iNOS(+/+)) mice. Functional outcome (motor and cognitive) during the first 20 days after injury, and histopathology at 21 days, were assessed in both studies. Treatment of rats with either of the iNOS inhibitors after TBI significantly exacerbated deficits in cognitive performance, as assessed by Morris water maze (MWM) and increased neuron loss in vulnerable regions (CA3 and CA1) of hippocampus. Uninjured iNOS+/+ and iNOS(-/-) mice performed equally well in both motor and cognitive tasks. However, after TBI, iNOS(-/-) mice showed markedly worse performance in the MWM task than iNOS+/+ mice. A beneficial role for iNOS in TBI is supported.
AB - Nitric oxide (NO) derived from the inducible isoform of NO synthase (iNOS) is an inflammatory product implicated both in secondary damage and in recovery from brain injury. To address the role of iNOS in experimental traumatic brain injury (TBI), we used 2 paradigms in 2 species. In a model of controlled cortical impact (CCI) with secondary hypoxemia, rats were treated with vehicle or with 1 of 2 iNOS inhibitors (aminoguanidine and L-N- iminoethyl-lysine), administered by Alzet pump for 5 days and 1.5 days after injury, respectively. In a model of CCI, knockout mice lacking the iNOS gene (iNOS(-/-)) were compared with wild-type (iNOS(+/+)) mice. Functional outcome (motor and cognitive) during the first 20 days after injury, and histopathology at 21 days, were assessed in both studies. Treatment of rats with either of the iNOS inhibitors after TBI significantly exacerbated deficits in cognitive performance, as assessed by Morris water maze (MWM) and increased neuron loss in vulnerable regions (CA3 and CA1) of hippocampus. Uninjured iNOS+/+ and iNOS(-/-) mice performed equally well in both motor and cognitive tasks. However, after TBI, iNOS(-/-) mice showed markedly worse performance in the MWM task than iNOS+/+ mice. A beneficial role for iNOS in TBI is supported.
UR - http://www.scopus.com/inward/record.url?scp=0032728075&partnerID=8YFLogxK
U2 - 10.1172/JCI6670
DO - 10.1172/JCI6670
M3 - Article
C2 - 10487779
AN - SCOPUS:0032728075
SN - 0021-9738
VL - 104
SP - 647
EP - 656
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
IS - 5
ER -