Hawkins R A, Mans A M, Davis D W, DeJoseph M R
Department of Anesthesia, Hershey Medical Center, Hershey, Pennsylvania 17033.
Am J Physiol. 1988 Mar;254(3 Pt 1):E310-7. doi: 10.1152/ajpendo.1988.254.3.E310.
Because glucose metabolism and functional activity in brain regions are normally coupled, knowledge of regional brain glucose use can yield insights into regional functional activity. The deoxyglucose (DG) method is widely used for this purpose in experimental animals and humans but questions have arisen regarding its limits and accuracy. Therefore an experiment was designed to compare the DG method on a structure-by-structure basis with another tracer of glucose use, [6-14C]glucose, in normal rats. The cerebral metabolic rates obtained using the two tracers were similar in the telencephalon, but the results using DG were substantially lower in the midbrain and hindbrain (diencephalon, 18%; mesencephalon, 20%; metencephalon, 29%; and myelencephalon, 35%). The primary DG metabolite, DG 6-phosphate (DG-6-P) was found to disappear in a non-uniform manner from the major brain structures: telencephalon less than diencephalon less than mesencephalon = metencephalon less than myelencephalon. Thus a correlation was found between the rate of DG-6-P loss and the extent to which the DG method gave lower values of glucose use. Thus this may explain, at least in part, the discrepancies between the two methods.
由于大脑区域的葡萄糖代谢与功能活动通常是相互关联的，了解大脑区域葡萄糖的利用情况有助于洞察区域功能活动。脱氧葡萄糖（DG）法在实验动物和人类中广泛用于此目的，但关于其局限性和准确性出现了一些问题。因此，设计了一项实验，在正常大鼠中，逐结构地将DG法与另一种葡萄糖利用示踪剂[6-¹⁴C]葡萄糖进行比较。使用这两种示踪剂获得的大脑代谢率在端脑中相似，但在中脑和后脑（间脑，18%；中脑，20%；后脑，29%；延髓，35%）中，使用DG得到的结果要低得多。发现主要的DG代谢产物，6-磷酸脱氧葡萄糖（DG-6-P）以不均匀的方式从主要脑结构中消失：端脑小于间脑小于中脑 = 后脑小于延髓。因此，发现DG-6-P损失率与DG法给出较低葡萄糖利用率值的程度之间存在相关性。因此，这至少可以部分解释两种方法之间的差异。
