IUGR remodels glycogen synthesis in CG-IUGR rats

This study investigates glucose metabolism changes in CG-IUGR rats and analyzes the potential underlying mechanisms. It identifies a critical warning period for glucose metabolism changes in CG-IUGR individuals from birth to adulthood, providing key intervention targets for the prevention and treatment of diabetes.

The CG-IUGR rat model was established by a low-calorie diet during pregnancy. Rats were measured weekly after birth for body length, weight, and BMI. Rats were assayed at 8-week-old for the following indicators. Serum fasting insulin (FINS) and insulin levels at 15 min after glucose load were detected. Glucose tolerance test (GTT) and insulin tolerance test (ITT) were carried out. Skeletal muscle/liver glycogen content, glycogen synthase (GS) expression, and GS activity were assessed before and after glucose load.

BMI and perirenal fat weight were significantly increased in CG-IUGR rats, showing catch-up growth. Serum FINS was decreased, whereas insulin at 15 min after glucose load was increased in CG-IUGR rats. GTT and ITT showed that CG-IUGR rats had significantly higher blood glucose levels at each time point after 15 min administration, suggesting their glucose intolerance and reduced insulin sensitivity. CG-IUGR rats manifested diminished skeletal muscle and liver glycogen content under basal conditions, accompanied by reduced GS expression and activity in these tissues. However, following a 15 min glucose challenge, a contrary trend was observed for all three parameters.

CG-IUGR rats have an increased susceptibility to DM. IUGR remodels glycogen synthesis in CG-IUGR rats, as demonstrated by the preferential storage of energy as glycogen.