Effect of L-arginine on the alterations of serum insulin-like growth factor and insulin-like growth factor binding protein 3 in 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 serum insulin-like growth factor-Ⅰ(IGF-I),insulin-like growth factor-Ⅱ(IGF-Ⅱ) and insulin-like growth factor binding protein 3 after different doses of L-arginine were administered.Methods: Thirty-six rats were divided into four groups: Control,Model,Low dose(100mg/kg L-arginine) and High dose(200mg/kg L-arginine)(n=9 each).IUGR was induced by passive smoking in rats from the last three groups.L-arginine was administered for the last two groups between day 8 and day 20 of gestation.On day 21 of gestation,the fetal rats were delivered by cesarean section.The body weight of fetal rats were measured.The levels of IGF-Ⅰ,IGF-Ⅱ and IGFBP-3 in the serum of pregnancy rats were measured by enzyme-linked immunoadsordent assay(ELISA).Results: The incidence of IUGR in control,model,low dose and high dose group was 3.92%,54.95%,5.55% and 9.09% respectively.The incidence of IUGR in Model group was increased significantly compared with that of control group(P0.01),and the IUGR incidence of L-arginine treated groups were decreased compared with model group(P0.01).The serum IGF-Ⅰand IGF-Ⅱlevels of pregnancy rats in model group were significantly lower than those of control group(P0.01).The levels of IGF-Ⅰand IGF-Ⅱin L-arginine treated groups were increased significantly than those of model group(P0.01).The serum IGFBP-3 levels of pregnancy rats in model group were significantly higher than those of control group(P0.01).The levels of IGFBP-3 in L-arginine treated groups were decreased significantly than those of model group(P0.01)and there were statistical difference between L-arginine treated groups and control group(P0.01). Conclusion: L-arginine can increase the levels of IGF-Ⅰand IGF-Ⅱin the serum of IUGR rats by passive smoking,decrease the levels of IGFBP-3,improve the development of fetal rats and decrease the incidence of IUGR.