Experimental model of hemodynamic homeostasis in post-traumatic stress disorder (PTSD)

Background . Experimental study of PTSD in animals helps to better understand the biological and behavioral mechanisms underlying it. The aim of the research . To study the reactions of the hemodynamic homeostasis system to the action of a psychoemotional stressor. Materials and methods . The study object was 24 male Wistar rats before and after stress stimulation in accordance with the European Convention for the Protection of Vertebrate Animals used in Experimental Research and Directive 86/609/EEC for the Protection of Animals used for Experimental and other Scientific Purposes. The study was approved by the Ethics Committee of the Federal State Budgetary Educational Institution of Higher Education “Altai State Medical University” of the Ministry of Health of the Russian Federation, Protocol No. 8 dated October 22, 2018. A model of mental trauma in rats caused by the experience of the death of one of the group members as a result of the actions of a predator was used as a stress factor. The state of blood flow was studied using an mDLS dynamic light scattering sensor using an original algorithmic approach. Diagnostic kits from Tekhnologiya-Standart (Russia) were selected as reagents for the hemostasis system. Statistical analysis was performed using the specialized R language version 4.1.3. Results . Under the influence of the stressor, a decrease in the overall intensity of microcirculation shear processes is noted, reflected in the total index (HI). A significant increase in the magnitude of the low-speed pool of shear velocities (HI1) is observed. Changes in the speed balance are integrated in the HI1/HI3 ratio, which significantly increases in young animals. In the older age group, the reverse process of decreasing the balance index occurs. For this group, one can assume a lower reactivity of the homeostatic regulation systems due to exhaustion and the formation of the allostatic load stage. In older animals, a significant dispersion of indicators is observed, which may also reflect the instability of the regulatory mechanisms of homeostasis. In the study of hemodynamics, age-related differences were manifested by an almost twofold decrease in APTT, which indicates an increased level of thrombus formation in the framework of the primary hemodynamic response to a stressor of significant intensity. Conclusion . Joint study of hemodynamics and hemostasis in laboratory animals helps to understand the reactions of regulatory systems and their age dynamics. The universality of the mechanisms of homeostatic regulation of the cardiovascular system allows extrapolation of data to humans.