Abstract
The effects of global cerebral ischemia on neurochemical parameters in the brain were examined in rats. Global cerebral ischemia was produced by temporary occulsion of the bilateral common carotid arteries 24 hr after the permanent electrocauterization of the bilateral vertebral arteries. In 10-min cerebral ischemic rats, the brain levels of monoamine were unaltered. The brain levels of r-aminobutyric acid (GABA), which increased about 1.5-fold just before recirculation, almost recovered to the levels of the sham operated group (sham ope. levels) within 5 min after recirculation. The brain levels of cyclic AMP (cAMP), although they altered a little just before recirculation, increased about 6-fold I min after recirculation, and they recovered to the sham ope. levels 3-5 min later. In 30-min cerebral ischemic rats, the brain levels of monoamine decreased to about 40% of the sham ope. levels just before recirculation, and norepinephrine (NE) and 5-hydroxytryptamine (5-HT) levels did not recover within 30 min after recirculation in the telencephalon. The brain GABA levels which increased about 2-fold just before recirculation, recovered to the sham ope. tevels in all brain regions by 30-min recirculation except for the levels in cerebral cortex and cerebellum. The brain cAMP levels which increased about 3.5-fold 10 min after recirculation, almost recovered 20 min later. However, the cAMP levels in the telencephalon decreased to levels lower than the sham ope. levels 30 min after recirculation. It is suggested that the changes of these neurochemical parameters in the telencephalon are related in part to the abnormalities o behavior and EEG activity which have been already reported.
