, Kyu Man Shin The purpose of this study is to investigate e effects of preischemic hyperglycemia on e alterations of'adenosine triphosphate and lactate concentrations in e acutefocal ischernic brain of the cats.
Acute focal cerebral ischemia in cats was induced by occlusion of the left middlecerebral artery through the postorbital technique. The experimental animals were divided into 3 goups: sham control, occlusion and recirculation groups. Each group was divided into 2 subgroups: normoglycemic and hyperglycemic groups.
The experimental results are obtained as fo11ows;
1) In normoglycemic subgroups of occlusion and recirculation proups, amount of adenosinetriphosphate in ischmic brain decreased significantly to 3.0% and 13.0% of the sham control,respectively(p < 0.001).
In hyperglycemic subgroups of occlusion and recirculation groups, amount of adenosine trisphosphate decreased a little more an at in normoglycemic subgroups, even so there wasno statistic significancy(p > 0.1).
2) In normoglycemic subgroups of occlusion and recirculation groups, amount of lactate inischemic brain increased signigicantly to 175.7% and 187.9% of the sham control, respectively(p < 0.001).
In hyperglycemic subgroups of occlusion and recirculation groups, amount of lactate increased nore than that in normoglycemic subgroups with statistic significancy(0.001 < p < 0.01).
These results suggest that hyperglycemia before ischemia serves to elevate glucose transport into brain tissue and thereby, to promote profound tissue acidosis throughanaerobic glycolysis caused by a failure of adenosine triphosphate stnthesis during the ischemicperiod.
Moyamoya disease is a cerebrovascular disease of unknown etiology, which is characterized by bilateral stenosis or occlusion at terminal portion of internal carotid artery and at proximal portion of anterior cerebral artery and/or middle cerebral artery and abnormal vascular network in the vicinity of the arterial occlusions. It occurs frequently in Asian countries, particularly in Korea and Japan, but is rare in Western countries. To establish the etiology of moyamoya disease, much about the pathology from autopsies, factors involved in its pathogenesis, and its genetics have been studied. It may occur at any age from childhood to adulthood and in general, initial manifestation is cerebral ischemic symptoms in children and intracranial hemorrhage symptoms in adults. Because it progress and cause recurrent stroke, early diagnosis and proper management has been recognized. Cerebral angiography is essential for definitive diagnosis and treatment plan. Magnetic resonance imaging/magnetic resonance angiography is useful for diagnosis and follow-up tools after revascularization. Evaluation of the cerebral hemodynamics by single photon emission computed tomography and positron emission tomography is useful for diagnosis and assessment of the severity of cerebral ischemia in moyamoya patients. Surgical revascularization is effective for moyamoya disease manifesting as ischemic symptoms, to prevent further ischemia and infarction. In hemorrhagic type moyamoya disease, revascularization can be considered. Direct bypass, indirect synangiosis and combined methods are used. Outcomes of revascularization are excellent in preventing transient ischemic attacks in most patients.
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