Histochemistry of Esterases and Peptidases

Abstract

Hydrolases have been the enzymes most amenable to histochemical analysis in the 25 years since Gomori and Takamatsu first demonstrated the alkaline phosphatases. The first substrate—Chloroacetyl Naphthol AS (synthesized by Gomori) was classed among the “non specific” esterases. Later this substrate was shown by us to be selective for endoproteases resembling chymotrypsin. The development of a greater knowledge of the nature of enzyme action and specificity provides the histochemist with a wide range of new possibilities for making new selective and sensitive substrates for the analysis of tissue enzyme location. The coupling of this development with the recent advances in examination of enzyme kinetics in situ increase the defining power of the histochemical tools. Further refinement of gross tissue analysis by the zymogram technique should help in the definition of tissue enzymes. In the end our aim is the closest approximation possible to the true character and spatial distribution of enzymes in cells and tissues, since only with this information will the real function of these constituents be revealed. The aim of this panel will be to assess the current technical state in this area of endeavor.