Evaluation of skin vascular reactivity in male and female rats under the influence of interval hypoxia

Abstract

It is known that microcirculation is, on the one hand, the central component that responds to dynamic changes in hypoxia, on the other hand, the central place where hypoxia mediates its adverse effects.

The role of vessels of the peripheral part of the microcirculatory bed in the formation of adaptation processes, their changes in different stages of training of white rats of different-sex remains the least studied issue, which is discussed in a few studies.

In this connection, the aim of the work was to study the effect of interval hypoxic training on the state of skin microcirculation in heterosexual rats in an experiment.

The study was conducted on white male and female Wistar rats, weighing 210-240 g. To achieve this goal, the state of the dynamic characteristics of blood microcirculation were studied: PM (constant perfusion parameter, p. u.), σ (standard deviation of the amplitude of the perfusion oscillation, p.u.) and Kv (coefficient of variation, %), all that provided an opportunity to analyze the general state of blood microcirculation. The amplitude-frequency spectrum of perfusion oscillations was also evaluated. The values of the amplitudes of the microvascular blood flow oscillations were determined by the mean square deviation of the blood flow oscillations. A non-invasive method for quantifying microvascular perfusion was used.

As a result of the study, it was shown that in male rats, compared with females, the perfusion index (PM) increases by 1.5 times, on the 1st day, with a decrease in the coefficient of variation (Kv) and an increase in the standard deviation (σ = 0.64 p.u.), which indicates an increased vascular tone of the microcirculatory bed.

The results obtained showed that during the formation of a compensatory reaction of the body to hypoxic exposure in female rats, as well as in male rats, on the 7th-14th day of the experiment, there was an inhibition of microcirculation up to 50% compared to this value before exposure. It is noted that the predominant role in the regulation of microcirculation belongs to the factor of passive regulation of microcirculation — cardiac, which is characterized by periodic changes in the volume of blood in the vessel, with a simultaneous increase in the parameter of the arithmetic mean perfusion rate. Thus, the leading mechanism for regulating vascular tone under the influence of simulated hypoxia, the nature of changes in blood volume in arterioles is determined by the pulse wave.