Göbel U, Schröck H, Seller H, Kuschinsky W
Department of Physiology, University of Heidelberg, Federal Republic of Germany.
Pflugers Arch. 1990 Jul;416(5):477-80. doi: 10.1007/BF00382679.
A specific population of neurons in the ventrolateral medulla (VLM) acts as the main integration center for the regulation of the sympathetic outflow to the cardiovascular system. In order to investigate whether this nucleus can be distinguished from its surroundings in the reticular formation of the medulla with respect to functional and morphological variables, the present study investigates several of such variables in this area on a quantitative basis. Local medullary glucose utilization was measured by the 2-[14C]deoxyglucose method; local medullary blood flow was quantified using iodo[14C]-antipyrine, and the local density of perfused capillaries was calculated by counting the number of intravascular fluorescent spots in brain sections after i.v. infusion of a globulin-coupled fluorescent dye. The values obtained from the VLM were compared with the respective values found in a reference area of the same brain section (gigantocellular nucleus). The values for glucose utilization, blood flow and capillary density were significantly (P less than 0.05) higher in the VLM than in the reference area (gigantocellular nucleus). This difference was 44.7% for glucose utilization, 34.1% for blood flow and 19.7% for capillary density. These data support the hypothesis that neurons in the VLM are specifically well supplied for being directly regulated in their activity by the PCO2 and pH in the arterial blood.
延髓腹外侧区（VLM）中的特定神经元群体是调节心血管系统交感神经输出的主要整合中心。为了研究该核在延髓网状结构中是否能在功能和形态学变量方面与其周围区域区分开来，本研究在定量基础上对该区域的几个此类变量进行了研究。采用2-[¹⁴C]脱氧葡萄糖法测量局部延髓葡萄糖利用情况；使用碘[¹⁴C]安替比林对局部延髓血流进行定量，并通过静脉注射球蛋白偶联荧光染料后计数脑切片中血管内荧光斑点的数量来计算灌注毛细血管的局部密度。将从VLM获得的值与同一脑切片的参考区域（巨细胞核）中发现的相应值进行比较。VLM中的葡萄糖利用、血流和毛细血管密度值显著（P小于0.05）高于参考区域（巨细胞核）。葡萄糖利用的差异为44.7%，血流为34.1%，毛细血管密度为19.7%。这些数据支持了这样一种假设，即VLM中的神经元在其活动中能通过动脉血中的PCO₂和pH受到直接调节，因而其供血特别充足。
