Lagerlund T D, Low P A
Neurophysiology Laboratory, Mayo Clinic, Rochester, Minnesota 55905.
Am J Physiol. 1991 Feb;260(2 Pt 2):R430-40. doi: 10.1152/ajpregu.1991.260.2.R430.
Our simulation of the release, diffusion, and consumption of oxygen in the capillaries and surrounding tissue of peripheral nerve now includes axial diffusion in blood and in surrounding tissue, in addition to bulk flow of blood and radial diffusion of oxygen out of the capillary. Our simulation assumes that the oxygen consumption of nerve tissue obeys Michaelis-Menten kinetics rather than zero-order kinetics as had been assumed in the Krogh model. We can calculate the oxygen tension at all points in the capillary and surrounding tissue as a function of distance from the center of the nearest capillary and distance along the capillary from the arterial to the venous end. Using average measured values for microcirculatory parameters in rat nerve, we calculated a distribution of oxygen tension values that agrees with experimentally measured distributions. The effects of axial diffusion and of Michaelis-Menten kinetics on the oxygen distributions were noticeable under normal conditions, but these effects were much more important in situations in which oxygen delivery was adversely affected.
我们对外周神经毛细血管及周围组织中氧气释放、扩散和消耗的模拟，现在除了血液的整体流动以及氧气从毛细血管的径向扩散外，还包括血液和周围组织中的轴向扩散。我们的模拟假设神经组织的氧气消耗遵循米氏动力学，而不是像克罗格模型中所假设的零级动力学。我们可以计算毛细血管和周围组织中所有点的氧分压，它是距最近毛细血管中心的距离以及沿毛细血管从动脉端到静脉端距离的函数。利用大鼠神经中微循环参数的平均测量值，我们计算出的氧分压值分布与实验测量分布相符。在正常情况下，轴向扩散和米氏动力学对氧气分布的影响是显著的，但在氧气输送受到不利影响的情况下，这些影响更为重要。
