“…1). Succinate dehydroge nase [4], a key enzyme of the citrate cycle, and glucose-6-phosphatase [3,27], fructose-1,6-bisphosphatase [25,28,29] as well as phosphoenolpyruvate carboxykinase [24,30,31,43], key enzymes of gluconeogenesis, were shown using histochemical, immuno histochemical or microbiochemical/microdissective techniques to be localized mainly in the periportal zone. Conversely, glucoki nase [25,28,32,33] and pyruvate kinase isoenzyme L [26,30,31,34], key enzymes of glycolysis, were located predominantly in the perivenous zone.…”