[Improvement of highly reproducible technique of four-vessel occlusion model and its study on metabolic changes of cerebral reperfusion in rats].
The four-vessel occlusion method introduced by Pulsinelli et al is widely used as an experimental model for reversible forebrain ischemia in rats. However, this model has a major problem in the difficulty assuring complete occlusion of the vertebral arteries by electrocauterization through the alar foramina of the first cervical vertebra. Anatomical basis of the vertebral artery suggested by Sugio et al indicates that the vertebral artery at the level of the second cervical vertebral is visible. In this study, we further developed highly reproducible model of reversible forebrain ischemia, which is modified four-vessel occlusion in rats. Male Wistar rats were subjected to four-vessel occlusion. Under microscope the visible vertebral arteries at the second vertebra could be easily electrocauterized and completely cut by microscissors to yield complete cessation of circulation of bilateral vertebral arteries without failure. After 24 hours, animals were subjected to 15, 30 and 45 minutes of forebrain ischemia by occluding both common carotid arteries with Sugita's temporary clips. 31P-magnetic resonance spectroscopy (31P-MRS) were obtained with a 6.3-T spectrometer to investigate sequential change of the in vivo brain energy metabolism. Our studies indicated that high energy phosphorus compounds were reduced in a few minutes after the induction of the forebrain ischemia, and they returned to the normal level after the recirculation. In addition, we monitored electroencephalogram (EEG) during the whole experimental period. The EEG showed a flat pattern after the induction of ischemia, and EEG recovered normal pattern within 12 hours.(ABSTRACT TRUNCATED AT 250 WORDS)
Toda
S
S
Department of Neurosurgery, Nippon Medical School, Tokyo, Japan.
Ikeda
Y
Y
Nakazawa
S
S
D000818:Animals; D001834:Body Water / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002545:Brain Ischemia / Q000378:metabolism* / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D004195:Disease Models, Animal; D004569:Electroencephalography; D017078:Laser-Doppler Flowmetry; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000378:metabolism* / Q000503:physiopathology