Introduction. Methods of laser Doppler flowmetry (LDF), tissue reflectance oximetry (TRO) and pulse oximetry are used to diagnose the microcirculatory-tissue system (MTS) condition and evaluate the tissue respiration. Use of these techniques in conjunction with a variety of functional stress tests allow the assessment of MTS parameters, reveal disorders of hemodynamics and evaluate the response of MTS to the functional tests. However, the dynamics of microcirculatory changes, tissue respiration

more »

... and possible disorders during the cold pressor test (CPT) have, till now, been little studied with the help of laser diagnostic techniques. The aim of this study was to evaluate the dynamics of changes in complex parameters of MTS during the CPT and to analyze the possible causes that affect these changes. Materials and methods. Using non-invasive optical methods of LDF, TRO and pulse oximetry, we investigated the dynamics of MTS parameter changes when using CPT in 32 healthy volunteers. Results. 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 a 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 disorder in the tone-shaping myogenic mechanisms regulating resistive microvessels, disturbances to the microcirculation of stagnant blood, or a combination of both of these factors. Conclusions. 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.