Stimulation of G-6-P independent glycogen synthase activity in the human placenta]

In immature human placentas, the activity of the I (glucose-6-phosphate-independent) form of glycogen synthase is significantly increased by insulin, glucose and by both compounds associated. In full-term placentas, the same kind of results has been found in each organ studied; due to the great variability observed in synthetase I control activities, the stimulation is significant only in the presence of insulin.