[Immunohistologic photometric quantification of pyruvate kinase content of rat tumors].

86 benign and malignant tumours were investigated histologically and immunohistologically. Staining intensity was measured by scanning-photometry. The computed optical density was digitalized and evaluated with an image analysis system. The results indicate a significantly higher amount of M2-PK in malignant tumours. In the adenocarcinomas of the mammary gland, the content of the M2-PK increased parallel with malignancy (p less than 0.01; r = 0.743). The M2-PK can serve as an indicator of the grade of malignancy in mammary tumours of the rat.