Abstract: | Myoepithelial cells (MC) were identified and types and forms of their hyperplasia in dysplasias and bening mammary gland tumors in dog and man were studied by indirect Coons' method using highly purified monospecific antiserum to smooth muscle myosin and by performing alkaline phosphatase test. Operation material from 75 patients and 12 dogs was studied by immunohistochemical method and from 26 persons and 12 dogs by histochemical method. Comparative analysis of immunohistochemical and histochemical identification of MC revealed differences in the results of staining in 7 out of 38 observations due to negative test for alkaline phosphatase in the presence of fluorescence. A high degree of coincidence of positive tests in immunohistochemical and histochemical methods of the study suggests that the test for alkaline phosphatase is a sufficiently reliable marker of MC. The principal similarity of types and forms of MC hyperplasia in canine and human mammary gland tissue indicates that dogs may be used as an adequate model for the study of various diseases of this organ. In addition to the known centripetal and centrifugal types, a uniformly concentric and smooth-muscle proliferations of MC were distinguished in parallel immunohistochemical and histochemical studies on variants of MC proliferation. |