Histopatological effects of stress on the heart muscle in rats
Tuba Demirci & Elvan Özbek
Objective: Stress causes negative effects at all the body especially the heart. As a result of the damage of secreting various hormones which stress cause to secrete in the body. During the stress, respiration, tension, heart speed and catecholamine level increase. All these can be considered as a risk factor for the heart disease. In our study, we aimed to examine stress possible histopathological changes on heart muscle.
Methods: Eight adult female Sprague Dawley rats were used in this study. Rats were randomly divided the control (n=4) and stress (n=4) groups. Chronic mild stress (CMS) model of depression was performed to the stress group during two weeks. At the end of the test, rats were slept with ketamin HCI and hearts were removed after opening their chest cage and their volumes were measured by the water immersion method. After this process tissue samples were blocked in paraffin blocks following routine histological protocol. Sections were taken with Leica RM2125RT microtome at the thickness of 45 mm and stained with hematoxylin -eosin. Preparations were light microscopically examined.
Results: It was observed that volumes of the hearts which belongs to the stress performed rats were significantly increased when compared with the control group (P< 0.05; independent samples t-test). In the sections of test group, there was an extension at the length of muscle fibers because of cytoplasmic swelling. Expansion of blood vessels in interstitium and presence of fat cells in some vessels were remarkable. Extensive vacuolar degeneration was also determined in the muscle fibers.
Conclusions: According to our findings, it is concluded that CMS can cause histopathological changes in the heart, such as coronary heart disease and high blood pressure.
Aknowledgement: This study was supported by the 2008/20-numbered Scientific Research Fund of our University.