Histochemical distribution of phosphorylase in the brain of the guinea-pig.

The histochemical distribution of phosphorylase activity in brain tissue of rodents was described by Shimizu and Okada (1957) using fresh, frozen tissue sections. The present article describes the distribution of phosphorylase activity in the brain of the guinea-pig as revealed by using tissue slices trimmed by hand instead of sections for incubation (Friede, 1956). This technique provides an improved localization of phosphorylase activity. The preparation of tissue for incubation seems to be a critical phase of the reaction since changes in the enzyme activity result from tissue damage (Friede, 1959a). The distribution of phosphorylase in brain tissue as defined by this technique will be compared briefly with an available large sampling of the distribution of succinic dehydrogenase in brain tissue. An inverse relationship between the two enzymes would be conceivable, considering the former one as a link of the anaerobic glycolytic breakdown and the latter as an indication of the presence of an oxidative Krebs cycle.