Mathematical modeling of time-dependent oxygen transport in rat peripheral nerve.

We modeled time-dependent transport of oxygen in peripheral nerve. Simulation began with a steady-state oxygen tension field determined by capillary diameter and length, intercapillary distance, blood-flow velocity, oxygen consumption rate, and arterial oxygen tension. One of these parameters was assumed to change rapidly to new constant value, producing time-varying oxygen tensions. A monoexponential or biexponential function characterized the oxygen tension time variation. Rate constants of the slower exponential ranged from 0.017 sec-1 to 0.46 sec-1, implying minimal time lag in response of peripheral nerve oxygen tensions to alterations in blood flow, arterial blood oxygenation, or metabolic demands.