Changes in nitric oxide production and cerebral blood flow before development of hyperbaric oxygen-induced seizures in rats

Tetsufumi Sato, Yoshimasa Takeda, Shingo Hagioka, Shan Zhang, Masahisa Hirakawa

Research output: Contribution to journalArticlepeer-review

45 Citations (Scopus)


The predictive value of increase in cerebral blood flow (CBF) was examined to detect hyperbaric oxygen (HBO2)-induced electrical discharge in artificially ventilated rats at three PaCO2 levels under 5 atmospheric pressures. The possible involvement of NO production in the mechanism of the increase in CBF was also assessed by measurement of major NO metabolites (NO2- plus NO3-) using a microdialysis technique at the left parietal cortex during HBO2 exposure. The onset times of electrical discharge, measured in the right frontal region, were significantly prolonged and shortened in the low PaCO2 group (79±21 min) and high PaCO2 group (27±7 min), respectively, compared to that in the normal PaCO2 group (37±5 min). Increase in CBF (200% of the pre-exposure level) was observed in every animal and was sustained until the appearance of electrical discharge. The onset time of increase in CBF was closely related to that of electrical discharge (R2=0.987), and the durations of increase in CBF were almost identical (11-14 min in mean) regardless of the PaCO2 level. The level of NO2- plus NO3- was unaffected by the initiation of HBO2 exposure and simultaneously increased up to 246±59% of control level with the onset of increase in CBF. There was a close relationship between changes in CBF and levels of NO2- plus NO3- (R2=0.544). These results indicate that monitoring of CBF is useful for the prediction of electrical discharge in artificially ventilated rats regardless of their PaCO2 levels and that the increase in NO production is related to the mechanism of increase in CBF.

Original languageEnglish
Pages (from-to)131-140
Number of pages10
JournalBrain Research
Issue number1-2
Publication statusPublished - Nov 9 2001
Externally publishedYes


  • Cerebrovascular circulation
  • Electroencephalography
  • Hyperbaric oxygenation
  • Microdialysis
  • Nitric oxide
  • Seizure

ASJC Scopus subject areas

  • General Neuroscience
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology


Dive into the research topics of 'Changes in nitric oxide production and cerebral blood flow before development of hyperbaric oxygen-induced seizures in rats'. Together they form a unique fingerprint.

Cite this