Effects of moderate, central fluid percussion traumatic brain injury on nitric oxide synthase activity in rats

Sudarkodi Alagarsamy, Douglas Dewitt, Kenneth M. Johnson

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Experimental traumatic brain injury (TBI) damages cerebral vascular endothelium and reduces cerebral blood flow (CBF). The nitric oxide synthase (NOS) substrate, L-arginine, prevents CBF reductions after TBI, but the mechanism is not known. This study examined the possibility that posttraumatic hypoperfusion is due to reductions in the substrate sensitivity of NOS which are overcome by L-arginine. Isoflurane-anesthetized rats were prepared for TBI (midline fluid-percussion, 2.2 atto), sham-TBI, or no surgery (control), and were decapitated 30 rain after injury or sham injury. The brains were removed and homogenized or minced for measurements of crude soluble or cell-dependent stimulated NOS activity, respectively. Baseline arterial oxygen, carbon dioxide, pH, or hemoglobin levels did not differ among control, sham, or TBI groups. Total cortical soluble NOS activity in TBI-treated rats was not significantly different from either untreated or sham groups when 0.45 μM or 1.5 μM L-arginine was added. Also, there were no differences in cell-dependent NOS activity among the three groups stimulated by 300 μM N-methyl-D-aspartate, 50 mM K+, or 10 μM ionomycin. These data suggest that TBI reduces CBF by a mechanism other than altering the substrate specificity or activation of nNOS.

Original languageEnglish (US)
Pages (from-to)627-633
Number of pages7
JournalJournal of Neurotrauma
Volume15
Issue number8
StatePublished - Aug 1998

Fingerprint

Percussion
Nitric Oxide Synthase
Cerebrovascular Circulation
Arginine
Ionomycin
Rain
Isoflurane
Vascular Endothelium
Wounds and Injuries
N-Methylaspartate
Substrate Specificity
Traumatic Brain Injury
Carbon Dioxide
Hemoglobins
Oxygen
Brain

Keywords

  • Arginine
  • Calcium
  • Cerebral blood flow
  • Cortex
  • Fluid percussion
  • Glutamate

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)

Cite this

Effects of moderate, central fluid percussion traumatic brain injury on nitric oxide synthase activity in rats. / Alagarsamy, Sudarkodi; Dewitt, Douglas; Johnson, Kenneth M.

In: Journal of Neurotrauma, Vol. 15, No. 8, 08.1998, p. 627-633.

Research output: Contribution to journalArticle

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