The Cervical Fold Suspension Model of Acute Stress in Rats and its Effect on the Liver

Abstract

Stress-related studies remain relevant notwithstanding its long-lasting history of research. Experimental studies are crucial in the study the impact of stress on a living organism. Currently, there is a great variety of simulation animal acute stress reaction models, in particular, cervical fold suspension of mice, which is cost effective and easy-to-use. However, there are insufficient data on using this technique to reproduce the acute stress response in rats, particularly, in studying the impact of immobilization stress on the liver. The purpose of the work was to study the impact of 6-hour-long cervical fold suspension simulation model of acute immobilization stress on the albino rats’ liver. Material and methods. Based on the international bioethical regulations, 20 male albino rats were involved into the study. The intact animals were assigned into group I (n=10) (control); the animals, exposed to 6-hour-long cervical fold suspension simulation model of acute immobilization stress were assigned to experimental group (n=10) (group II). After euthanasia, macro- and microscopic examination of the liver was performed. Micro-specimens were stained with hematoxylin and eosin. Results and discussion. The macroscopic examination of the liver did not reveal any visual differences in the rats of the experimental group compared to the control ones. Histological study of the liver specimens of group II rats showed that the experimental model of simulated acute immobilization stress in rats by atraumatic cervical fold suspension for 6 hours caused significant changes. They were especially pronounced in the bloodstream of the liver, manifested by the plethora and the phenomena of interlobular vein thrombosis. The central veins were also plethoric and a significant dilatation of the perisinusoidal spaces was noted. Changes in the hemomicrocirculation were characterized by manifestations of blood stasis and sludge in most sinusoidal capillaries. We detected the phenomena of tissue infiltration by the segmented neutrophils, as well as macrophages and lymphocytes perivascularly and in the portal tracts. Changes were also found in the liver cells, namely, the phenomena of karyopyknosis; subcapsular focal colliquational necrosis in the individual hepatocytes; hydropic dystrophy in hepatocytes located on the periphery of the liver lobuli. Conclusion. The implementation of experimental model of acute immobilization stress in rats by atraumatic cervical fold suspension caused significant histological changes in rat liver

Morphological changes of the hepatobiliary system and salivary glands under the influence of stress

“…Fixation by the neck fold was chosen as the basis for reproducing the acute immobilization stress experimental model [7]. For this purpose, non-anesthetized rats were immobilized by hanging by the neck fold with an atraumatic clamp for 6 hours.…”

The Cervical Fold Suspension Model of Acute Stress in Rats and Its Impact on the Spleen

“…На сьогодні відомі та широко впроваджені у дослідницьку роботу численні моделі відтворення гострих стресових реакцій у експериментальних тварин [3]. На особливу увагу, з нашого погляду, заслуговують ті, які є нескладними у виконанні, не потребують використання спеціальних або вартісних технічних засобів, не порушують чинних принципів біоетики [4]. Серед таких експериментальних моделей відтворення гострої стресової реакції у мишей є фіксація за шийну складку [3].…”