We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Effects of Moderate Hypothermia on Constitutive and Inducible Nitric Oxide Synthase Activities After Traumatic Brain Injury in the Rat.
- Authors
Chatzipanteli, Katina; Wada, Kojiro; Busto, Raul; Dietrich, W. Dalton
- Abstract
We investigated the effects of therapeutic hypothermia (30°C) on alterations in constitutive (cNOS) and inducible (iNOS) nitric oxide synthase activities following traumatic brain injury (TBI). Male Sprague-Dawley rats were anesthetized with 0.5% halothane and under-went moderate (1.8-2.2 atm) parasagittal fluid-percussion (F-P) brain injury. In normothermic rats (37°C) the enzymatic activity of cNOS was significantly increased at 5 min within the injured cerebral cortex compared with contralateral values (286.5 ± 68.9% of contralateral value; mean ± SEM). This rise in nitric oxide synthase activity was significantly reduced with pretraumatic hypothermia (138.8 ± 17% of contralateral value; p < 0.05). At 3 and 7 days after normothermic TBI the enzymatic activity of cNOS was decreased significantly (30 ± 8.4 and 28.6 ± 20.9% of contralateral value, respectively; p < 0.05). However, immediate posttraumatic hypothermia (3 h at 30°C) preserved cNOS activity at 3 and 7 days (69.5 ± 23.3 and 78.6 ± 7.6% of contralateral value, respectively; mean ± SEM; p < 0.05). Posttraumatic hypothermia also significantly reduced iNOS activity at 7 days compared with normothermic rats (0.021 ± 0.06 and 0.23 ± 0.06 pmol/mg of protein/min, respectively; p < 0.05). The present results indicate that hypothermia (a) decreases early cNOS activation after TBI, (b) preserves cNOS activity at later periods, and (c) prevents the delayed induction of iNOS. Temperature-dependent alterations in cNOS and iNOS enzymatic activities may participate in the neuroprotective effect of hypothermia in this TBI model.
- Subjects
COLD therapy; NITRIC-oxide synthases; BRAIN injuries
- Publication
Journal of Neurochemistry, 1999, Vol 72, Issue 5, p2047
- ISSN
0022-3042
- Publication type
Article
- DOI
10.1046/j.1471-4159.1999.0722047.x