[Enzyme histochemical studies on the macula and Goormaghtigh cells of the guinea pig kidney].

Starting from the ultrastructural differences observed between the juxtaglomerular apparatus of the rat and that--only very rarely analysed--of the guinea pig kidney, the authors supposed that enzymhistochemical differences might also exist. This hypothesis could be confirmed by the results obtained in the Macula densa- and the Goormaghtigh-cells (Tab. 1 and 2). Indeed, in both places the Isocitrate dehydrogenase- and the Malate dehydrogenase-activities are stronger in the guinea pig than in the rat. On the other hand, the Glucose-6-phosphate and the 6-Phosphogluconate dehydrogenases show clearly weaker activities in the guinea pig Macula-cells compared with those of the rat, where these two enzymes give by far the strongest reaction. Metabolic differences might be related to the described diversities of the enzyme equipment.