[Activity and isoenzymes of lactate dehydrogenase in tissues of amphibians (Xenopus laevis, Ambystoma mexicanum, Triturus alpestris and vulgaris) and the response in the fat body of Xenopus males to gonadotropin injection (author's transl)].

Lactate-dehydrogenase activity was determined by the optical test method using pyruvate as substrate and the isoenzymes were separated by vertical starch gel electrophoresis. Species-specific and organ-specific characteristics of the total activity and the isoenzyme patterns of the four amphibian species are compared with those of rat and mouse. Application of gonadotropin increases the amount of soluble protein and the lactate-dehydrogenase activity in the fat body of Xenopus and the isoenzyme pattern shows a shift of intensity towards the basic bands. Testis does not respond to this treatment.