[Functional Status of Microcirculatory-Tissue Systems during the Cold Pressor Test]

Using non-invasive optical methods of laser Doppler flowmetry, tissue reflectance oximetry and pulse oximetry, we investigated the dynamics of parameter changes of microcirculatory-tissue systems (MTS) when using cold pressor test (CPT) on 32 conventionally healthy volunteers. According to differences in the recovery rate of oxygen consumption during CPT, volunteers can be conditionally divided into 2 groups: 1--displaying normal physiology and 2--with a tendency to angiospasm and lack of functional recovery of the MTS. To identify possible causes of angiospasm, we performed a detailed analysis of blood flow oscillations. This analysis revealed that the cause of angiospasm may be a violation of the tone-shaping myogenic mechanisms regulating resistive microvessels, disturbances to the microcirculation of stagnant blood, or a combination of both of these factors. Use of the CPT for functional assessment of MTS allows us not only to estimate the reserve capabilities of the MTS, but also to identify--at a pre-clinical stage-propensity to angiospasm, which has practical value in the clinic.