Functional status of microcirculatory-tissue systems during the cold pressor test

The time course of changes in the parameters of microcirculatory–tissue systems (MTSs) during the cold pressor test (CPT) was investigated in 32 conventionally healthy volunteers by noninvasive optical methods of laser Doppler flowmetry (LDF), tissue reflectance oximetry (TRO), and pulse oximetry. Depending on the oxygen consumption recovery rate in the CPT, the subjects were conventionally divided into two groups, one with a normal physiology and the other with a tendency to vascular spasm and lack of functional recovery of the MTSs. Blood flow oscillations were analyzed in detail to identify the possible causes of vascular spasm. The causes might include a distortion of the tone-shaping myogenic mechanisms that regulate resistive microvessels, blood congestion in microcirculation, or a combination of both of the factors. The CPT used to assess the MTS function was assumed to report the MTS reserve and to detect a propensity for vascular spasm at a preclinical stage, thus being of a potential applied significance.