The role of histochemical investigations in metabolic disorders affecting the liver

The application of histochemical techniques to the study of metabolic disorders affecting the liver can yield considerable information, provided the methods used are sound and the interpretation is not over-enthusiastic. The appropriate methods can give insight into liver function and can identify and localize a wide variety of carbohydrates, lipids, proteins and enzyme activities. It is often thought that tissue taken for histochemical analysis cannot be used for morphology, but properly prepared tissue will provide the architectural and cytological detail necessary for histological assessment. There are several advantages to the histochemical approach, the main ones being economy of use of the valuable tissue sample (in theory about 100 sections and tests can be done on a 1 mm depth of tissue) and that the results of the tests can be assessed in relation to the structure of the liver. There are two areas in which histochemical investigations are used: firstly, to detect cellular constituents, structures and cells not otherwise visible by routine methods. In this mode, histochemistry is an extension of the histological approach and constitutes a 'super haematoxylin and eosin' stain. Secondly, it is possible to assess enzyme activities and their localization, and in some well-defined instances to offer reliable indications of whether there is deficient activity, normal activity or enhanced activity. Although there is a body of opinion which believes that quantitative enzyme histochemistry is possible and reliable, the author has not found the data, in particular or lysosomal enzymes, to be reliable and remains unconvinced that this technique has a place in the study of pathological tissue.(ABSTRACT TRUNCATED AT 250 WORDS)