Experimental research on effect of insulin-like growth factor on placentas of intrauterine growth retardation rats

[Objective] This study aimed to explore the effect and its mechanism of L-arginine on IUGR rats by the alterations of insulin-like growth factor-Ⅰ(IGF-Ⅰ), insulin-like growth factor-Ⅱ(IGF-Ⅱ) and insulin-like growth factor binding protein 3 in the placentas of IUGR rats after different doses of L-arginine were administered. [Methods] After establishment of IUGR model by passive smoking, thirty-six rats were divided into four groups: Control, Model, Low dose (100 mg/kg L-arginine) and High dose (200 mg/kg L-arginine) (n=9 each). The levels of IGF-Ⅰ, IGF-Ⅱ and IGFBP-3 in placentas were measured by enzyme-linked immunoadsordent assay (ELISA). [Results] The average placental weight of L-arginine treated groups were increased significantly compared with Model group (P 0.01). The placental levels of IGF-Ⅰand IGF-Ⅱin L-arginine treated groups were increased significantly than those of Model group (P 0.01). The placental levels of IGFBP-3 in L-arginine treated groups were decreased significantly than those of Model group (P 0.01). [Conclusions] L-arginine can increase the levels of IGF-Ⅰand IGF-Ⅱ, decrease the levels of IGFBP-3 in placentas of IUGR rat, and improve the development of fetal rats.