Evaluation of desmin expression by immunohistochemistry in myocardial cells of dogs with dilated cardiomyopathy.

The experimental material consisted of 20 dogs: 15 Doberman pinschers with diagnosed dilated cardiomyopathy (DCM), and five healthy dogs (three mixed breeds, one Doberman pinscher, one Boxer). DCM was confirmed by electrocardiography and echocardiography before euthanasia. After euthanasia, an autopsy was performed and myocardial samples were collected from the right and left ventricles, intraventricle septum, and right and left atrium. The samples for the histopathological and immunohistochemical analysis were fixed in with 7% formalin in PBS buffer. The presence of desmin was semiquantitatively evaluated under a light microscope. The normal levels of desmin expression in immunohistochemical staining were observed only in the control dogs. The desmin expression was elevated in 15 dogs with severe DCM The immunochemical method allowed for the evaluation of desmin activity in cardiomyocytes, and showed three patterns of its expression (increase expression, decrease expression, heterogeneous expression). The desmin expression was abnormal in the myocardial samples in dogs with DCM. We observed an increase expression of desmin in 10 dogs with moderate and a decrease expression of desmin in five dogs with advanced DCM. The relationship between the desmin expression and the progression of heart failure secondary to DCM requires further studies.