Glycogen synthetase activity in rat muscle in thermal trauma.

The glycogen synthetase activity and glycogen concentration were studied in rat skeletal muscle 24 hours after infliction of a burn. The active I-form of the enzyme was reduced. The total synthetase activity was unchanged. Expressed as a percentage of total synthetase activity, the I-form was decreased from 43.4% in control rats to 27.6% in burned rats. The fasting concentrations of serum insulin and muscle glycogen were not altered by the burn. The reduced synthetase I-form may explain the reduced glycogen storage capacity, demonstrated previously after a similar burn.