Electroencephalogram is Activated by Addition of
Pentobarbital in the Isolated Perfused Head of the Rat
A. TAGAWA1, O.
MOKUDA2, Y. SAKAMOTO2, N. SHIMIZU1
1Department of Neurology, Teikyo University
School of Medicine, Ichihara Hospital and
2Third Department of Internal Medicine, Teikyo
University School of Medicine, Ichihara Hospital,
Asahimachi, Niigata City, Niigata, Japan
Received November 15, 2001
Accepted August 7, 2002
Summary
To evaluate the direct effects of a barbiturate on cerebral
functions without its influence on brain perfusion pressure,
circulatory hormones and metabolites, the electroencephalogram
(EEG) was studied in the isolated rat head. Male Wistar rats
were anesthetized, and EEG electrodes were inserted into the
cranium. A Krebs-Ringer bicarbonate buffer solution containing
heparinized rat whole blood, 20 mmol/l glucose, 200 mmol/l
mannitol and 0.1 mg/ml dexamethasone was used for the perfusate.
The bilateral common carotid arteries were cannulated, pumped at
a rate of 6 ml/min and the head was isolated. The venous
effluent was reoxygenated and recirculated into the brain.
Twenty-five min after isolation of the heads pentobarbital was
added to the perfusate at concentrations of 0.1, 0.5 and 2.5
mg/ml. EEG was recorded before and during perfusion. EEG
activity could be recorded for more than 25 min after the
beginning of perfusion. EEG activity gradually declined from
42±5 μV before perfusion (in vivo) to 4±1 μV at 25 min after the
beginning of perfusion. Then, 3 min after the addition of
pentobarbital, the EEG activity became significantly higher in
the high dose groups; 12±3 μV in the 0.5 mg/ml group (p<0.05)
and 12±1 μV in 2.5 mg/ml group (p<0.05) compared with the group
without pentobarbital (2±2 μV). The present study suggests that
a barbiturate has mitigating effects on the brain damage induced
by the in vitro brain perfusion.
Key
words
In vitro • Isolated brain perfusion • Electroencephalogram •
Pentobarbital
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requests
Asako Tagawa M.D., Department of Neurology, Brain Research
Institute, 1-757 Asahimachi, Niigata City, Niigata 951-8585,
Japan. E-mail:
asako54@ bri.niigata-u.ac.jp
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