Abstract
Glucose 6-phosphatase development before and after birth follows a similar pattern in guinea-pig liver, kidney and intestinal mucosa. The properties in kinetic characteristics of glucose 6-phosphatase show no change during development, so that the large increases in activity after birth are due to increased enzyme concentration. The activities of phosphoglucomutase, phosphoglucose isomerase, glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase in developing liver and kidney show, on comparison, a number of distinct changes in the liver. The activities are sufficient to permit glucose 6-phosphate metabolism by the known metabolic pathways, but the changes reveal no means of control of glycogen metabolism during development. There are limitations to the value of activity determinations for glucose 6-phosphate-metabolizing enzymes in the developmental period.