RESUMEN
Objective:To study the different effects of pre-pregnancy obesity (PO), excessive gestational weight gain (EGWG), pre-pregnancy obesity combined with excessive gestational weight gain (PO+EGWG) of maternal rats on glucose and lipid metabolism in neonatal offspring, and to explore the possible mechanisms.Methods:Animal models of PO, EGWG and PO+EGWG were established by feeding SD rats with high-fat diets at different periods. Thirty-six SD rats were randomly divided into four groups, with nine rats in each group. The control group had a normal diet before and during pregnancy. The PO group had a high-fat diet before pregnancy and a normal diet during pregnancy. The EGWG group had a normal diet before pregnancy and a high-fat diet during pregnancy. And the PO+EGWG group had a high-fat diet before and during pregnancy. The body weight of maternal rats before and during pregnancy and the birth weight of neonatal rats were recorded. Nine male neonatal rats in each group were selected, fasting blood glucose levels were detected by glucometer, fasting insulin levels were detected by enzyme-linked immunosorbent assay kit, hepatic triglyceride and cholesterol levels were detected by glycerol phosphate oxidase-peroxidase method, hepatic lipid deposition were observed by hematoxylin-eosin staining and oil red O staining. The mRNA levels of hepatic key genes in glucose metabolism pathway IR, IRS, AKT and lipid metabolism FASN, SREBP1c, PPARα were detected by reverse transcription-polymerase chain reaction analyses.Results:The pre-pregnancy weight of maternal rats in high-fat diet group before pregnancy (PO group and PO+EGWG group) was significantly higher than those in normal diet group (control group and EGWG group). The percentage of weight gain of maternal rats in high-fat diet group during pregnancy (EGWG group and PO+EGWG group) was significantly higher than those in normal diet group (control group and PO group) ( P<0.05). The birth weight of neonatal rats in PO group, EGWG group and PO+EGWG group were significantly higher than that in control group ( P<0.05), and the birth weight of neonatal rats in PO+EGWG group was the largest. The fasting glucose, insulin level and insulin resistance index of newborn rats in PO, EGWG and PO+EGWG groups were higher than those in the control group, and the mRNA levels of IR, IRS and AKT were lower than those in the control group, but the differences were not statistically significant ( P>0.05). The hepatic triglyceride and cholesterol contents and mRNA levels of FASN and SREBP1c were higher in the EGWG and PO+EGWG groups than those in the control group, and the mRNA level of PPARα was higher in the PO+EGWG group than in the control and PO groups, with statistically significant differences ( P<0.05). Conclusions:Animal models of PO, EGWG and PO+EGWG were successfully constructed by feeding SD rats with high-fat diets before pregnancy, during pregnancy, before and during pregnancy. PO+EGWG had the most significant effects on the birth weight and glucose and lipid metabolism in neonatal offspring. Compared with EGWG, PO had a relatively significant effect on glucose metabolism in neonatal offspring. And compared with PO, EGWG had a relatively significant effect on lipid metabolism in neonatal offspring. The effects of maternal obesity on glucose and lipid metabolism in neonatal offspring were considered to be related to the expression changes of genes in glucose and lipid metabolism.