GENDER DIMORPHISM OF CHANGES IN THE SKIN MICROCIRCULATION OF RATS ON THE BACKGROUND OF ACUTE COLD TRAUMA

Abstract

Gender factors play an important role in the prevention, preva- lence and specifics of the course of various pathological conditions, among which cold injury occupies an important place. The role of gender in its pathogenesis remains poorly understood. The aim. To assess sex-specific changes in the microcirculation of target organs exposed to extremely low temperatures during experimental acute cold trauma (ACT) in rats. Materials and methods. Experiments were performed on male and female sexually mature and castrated Wistar rats. Acute cold trauma (ACT) was modeled by keeping the animals at -180ºС for 2 hours. The microcirculation coefficients of the skin of the hind limbs, auricles, and tail of animals were determined using Biopas electrophysiological equipment (USA) non-invasively using a surface sensor. We compared the changes before and 30 minutes after the action of the cold factor. Statistical processing of the results was carried out using standard descriptive methods. The results. A 2-hour stay of animals under the influence of extremely low temperatures causes a significant drop in blood supply in animals of both sexes. The degree of changes has a clear sexual dimorphism with a predom- inance of pathological processes in male animals. In males, the coefficient of microcirculation of the lower limbs and auricles decreased by 72.2 and 55.3 %, and in the tail by 35.1 %, compared to this indicator before the effect of the cold factor (p < 0.05), on the other hand, in female rats changes in similar indicators were 66.5 and 44.3 % (lower limbs and auricles), and tail perfusion by 18.6 % (p < 0.05). ACT in castrated female rats caused more extensive hemoperfusion disorders compared to males: the microcirculation index of the tail, hind limbs, and auricle in male rats on the background of ACT decreased by 25.4, 66.4, and 40.7 %, respectively (p < 0.05), whereas in animals of the opposite sex – by 32.5, 78.8 and 47.4 %, respectively. Conclusion In sexually mature female rats without changes in hormonal status, a greater resistance to microcirculation disorders during experimental acute cold injury was found. The reason for these differences is the effect of sex hormones, since castration of males increases the resistance of the vascular system of animals to the action of a cold factor, while ovariectomy of females – on the contrary, increases the degree of microcirculatory lesions of the most vulnerable organs to the action of extremely low temperatures