Study of the cevebral blood flow and metabolisar in hydrocephalus

本文报告了婴儿脑积水的特征性CBF和rCMR 02模式。在PET扫描上，OEF不随CBF降低而增加。而在高岭土混悬液脑积水大鼠模型中，rCMRglc在早期不依赖于CBF的降低而升高。我们推测DG法测定的rCMRglc可能反映了脑积水病理生理过程中的无氧代谢的价值。本研究将实验性脑积水大鼠分为急性期（注射后2周）和慢性期（注射后6周），通过比较DG法和仅代表有氧代谢的6-标记葡萄糖法测定的rCMRglc，探讨脑积水大鼠糖代谢的无氧变化。注射生理盐水作为对照。急性期DG代谢高于葡萄糖代谢。主要分布在大脑皮质、丘脑、下丘脑和胼胝体。感觉运动皮层和丘脑差异有显著性。而慢性期模型仅在感觉运动皮层出现明显的图像差异。对照组无显著差异。提示脑积水早期存在无氧代谢改变。急性期无氧代谢的激活占主导地位，可弥补能量的不足。慢性期无氧代谢和有氧代谢的降低可能提示不可逆的组织损伤。

We reported characteristic pattern of CBF and rCMR02 in infantile hydrocephalus. OEF does not increase as CBF decrease on PET scan. However, in experimental hydrocephalus rat model made by Kaolin suspension injection, rCMRglc increased independent of decreased CBF in early stage. We speculated that rCMRglc measured by DG method may cotain the value of anaerobic metabolism which is involved in the pathophysiology of hydrocephalus. In the present study, we tried to clarify the anaerobic changes of glucose metabolism in experimental hydrocephalus rat by comparison of rCMRglc measured by DG method and 6-labeled glucose method which represents only aerobic metabolism.The phase of hydrocephalus was devided into acute phase of 2-weeks after the injection and chronic phase of 6-weeks after the injection. Saline was injected as control. In acute phase, the DG metabolism was higher than that of glucose. It was recognized mainly in the cerebral cortices, thalamus, hypothalamus and corpus callosum. There were significant differences in sensorymotor cortex and thalamus. However, notable deifference of images was recognized only in sensorymotor cortex in chronic phase model. There was no significant difference in control. These results suggest that anaerobic change of metabolism exists in the early stage of hydrocephalus. Activation of anaerobic metabolism, dominant in acute phase, may compensate for shortage of the energy. The decrease of anaerobic and aerobic metabolism in chronic phase may suggest the irreversible tissue damage.