Microscopic changes in the vessels of the adrenal gland and the pancreas under conditions of immobilization stress on the background of hypothyroidism

Abstract

Summary. Stress is a state that leads to disruption of homeostasis and is defined as the response of the brain and body to stimuli arising from signals, both internal and from the environment. The aim of the study – to examine the microscopic changes in the vessels of the pancreas and adrenal gland under the conditions of immobilization stress against the background of hypothyroidism. Materials and Methods. The experiment was conducted on 20 mature white male rats. Hypothyroidism was modeled by daily per os injection using a probe of the pharmacopoeial mercazole thyreostatics at a dose of 25 mg/kg during 21 day. Acute immobilization stress was modeled by tying experimental rats in a supine position in 4 limbs without restriction of head mobility for 3 hours. The study was conducted 2 hours later (anxiety stage) after the end of the stress impact. Histological studies were carried out according to generally accepted methods. Results. In rats, most of the vessels of the pancreas were of a typical shape, but some of them had partial deformation of the wall, slight swelling of all wall tunics was determined, the lumens of medium and large size arteries were moderately dilated. The lumens of the large and medium size veins were blood-filled, there was slight edema of the perivascular spaces. The lumens of some hemocapillaries were expanded, blood-filled with the formation of a sludge phenomenon. Adrenal vessels had more pronounced destructive changes. The internal elastic membrane was indistinct, thinned, discontinuous, the media was thickened with signs of edema. Microvessels with a damaged wall were found, which led to diapedesis of erythrocytes, and in the zona glomerulosa and zona fasciculata such places were found only singly. In the medulla of the organ, vessels were with wide lumens and perivascular edema, adventitia infiltrated with leukocytes, the most pronounced changes were in the wall of sinusoidal hemocapillaries. Conclusions. It has been established that under conditions of simulated stressors in hypothyroidism, changes occur in all structural components of the walls of blood vessels, both in the pancreas and in the adrenal glands

Keywords

• stress
• hypothyroidism
• pancreas
• adrenal gland