The effect of maternal diabetes on the fetal insulin/insulin-like growth factor system and fetal organ weights.

WHITE VERÓNICA; JAWERBAUM ALICIA; CAPOBIANCO EVANGELINA; DESOYE GERNOT; HIDEN URSULA

Lille

Congreso; 44th meeting of the Diabetes and Pregnancy Study Group; 2012

Diabetes and Pregnancy Study Group

(IGF) system has been implicated in fetal growth regulation. This study tested the hypothesis that maternal diabetes alters the fetal insulin/IGF system in a tissue specific manner. Wistar rats are rendered diabetic by neonatal administration of streptozotocin. Control and diabetic adult rats were mated and allowed to get to near term pregnancy. At day 20.5 of gestation fetal weight as well as weight of placentas, fetal heart, lung, liver, stomach, intestine and pancreas were determined. Maternal and fetal concentrations of insulin, IGF1 and IGF2 were measured by ELISA. Expression levels of IGF1, IGF2, IGF1R, IGF2R, IR, IGFBP1, IGFBP2, IGFBP3 were measured by qPCR. Distribution of insulin receptor isoforms in placenta liver lung heart and stomach were determined by RT-PCR. All organ weight except pancreas and stomach were increased. There was a prominent increase in fetal circulating insulin and IGF1. The expression pattern of the components of the insulin/IGF axis from placenta and fetal organs, particularly on the fetal heart, was affected by maternal diabetes in an organ specif manner. In general, the insulin/IGF system was upregulated, particularly in the fetal heart, whilst there were downregulated in the fetal lung. Relative insulin receptor isoform expression was unchanged. Fetal organ growth is augmented in this rat model of mild diabetes. This is accompanied by elevated insulin and IGF1 levels and alterations in the insulin/IGF system in the fetus in a tissue- and gene- specific manner. Particularly the fetal heart responded in altered expression of almost all components of the insulin / IGF system.