Abstract
Uridine diphospho glucose (UDPG)-glycogen glucosyltransfers (glycogen synthetase or transferase) activity was measured in separate retinal homogenates of alloxan-diabetic rats with the use of 14C incorporation into glycogen from uridine-5'-diphosphoglucose 14C (UDPG-14C). Activity decreased in the retinas of rats diabetic for six months compared to levels in retinas of control rats. Activity in the diabetic rat retina decreased within 20 hours after alloxan administration to the same low levels as those in rats which were diabetic for six months. Administration of insulin to rats which were diabetic for several days increased the UDPG-glycogen glucosyltransferase activity in the retina to nearly normal levels.