[Histochemical determination of sorbitol dehydrogenase in the rat kidney. Indicator histochemical,...

By comparative indicator- and immunohistochemical technique we have investigated the distribution of sorbitol dehydrogenase (SoDH) in rat kidney. In this connection we have tested some parameters which influenced the histochemical demonstration of SoDH activity by tetrazolium salt indicator technique (e.g. prefixation of tissue sections, elution behaviour of the enzyme, influence of different dialysis membranes, composition of incubating medium). According to these studies the enzyme was demonstrated in native cryostate sections by membrane incubating technique. For the immunohistochemical demonstration of SoDH specific antibodies against this enzyme were prepared in rabbits and used for indirect immunofluorescence method and for unlabelled antibody enzyme (PAP) technique. A good agreement of sorbitol dehydrogenase localization in rat kidney was observed with all the tested methods, but also some discrepancies exist in connection with the glomerular localization of the enzyme.