Glucose metabolic and gluconeogenic pathways disturbance in the intrauterine growth restricted adult male rats.

OBJECTIVE

To explore the molecular mechanism of type 2 diabetes in intrauterine growth restricted adult rats through determination of blood glucose and expression of gluconeogenic enzymes in liver.

METHODS

Male intrauterine growth restriction (IUGR) offspring induced by maternal protein-malnutrition and normal controls were studied. The body weights of offspring rats were weighted from birth to 12 weeks of age. Fasting plasma glucose and insulin levels were determined by glucose oxidase method and enzyme-linked immunosorbent assay (ELISA) respectively at 1 week, 8 weeks, and 12 weeks. Peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1 alpha), phosphoenolpyruvate carboxykinase (PEPCK), and glucose-6-phosphatase (G6Pase) mRNA and protein levels in liver were measured by real time RT-PCR and Western blot in newborn rats (Week 1) and adult rats (Week 12).

RESULTS

Birth weights of IUGR rats were significantly lower than those of controls until 4 weeks later, when IUGR rats caught up to controls. Between 8 and 12 weeks, the growth of IUGR rats surpassed that of controls. No significant differences were observed in blood glucose and insulin levels at newborn rats between the two groups. However, by the end of 8 weeks IUGR rats developed hyperinsulinemia and high insulin resistance index. At the age of 12 weeks, IUGR rats had mild fasting hyperglycemia. In addition, hepatic PGC-1 alpha mRNA and protein levels as well as hepatic mRNA levels of PEPCK and G6Pase at Week 1 and Week 12 in IUGR rats were all significantly higher than those of controls (P<0.05).

CONCLUSIONS

As a result of intrauterine malnutrition, the expression of gluconeogenic genes is exaggerated in offspring. This change stays through adulthood and may contribute to the pathogenesis of type 2 diabetes.