Maternal fructose intake during pregnancy modulates hepatic and hypothalamic AMP‐activated protein kinase signalling in a sex‐specific manner in offspring

Abstract

Dietary fructose ingestion during gestation affects carbohydrate metabolism in the offspring. In the present study, we investigated the effects of excess fructose intake during pregnancy on hepatic and hypothalamic AMP-activated kinase (AMPK) expression and phosphorylation, as well as hepatic glucose-6-phosphatase (G6Pase) activity in offspring. Pregnant Wistar rats received normal chow and 100g/L fructose solution or normal water during gestation ad libitum. On gestational Day 21, some dams were killed and plasma samples and fetuses were collected. The remaining dams received normal water after spontaneous delivery during lactation. Pups were killed on postnatal Day 22 and the plasma, liver and hypothalamus were collected and analysed. Plasma glucose and insulin levels increased in female but not male offspring in the fructose group. Although the mRNA and total protein levels of AMPKα were unchanged, levels of phosphorylated AMPKα protein in the fructose group of female offspring were significantly lower in the liver and 4.6-fold higher in the hypothalamus. The hepatic protein level of sirtuin 1, which is involved in AMPK phosphorylation and activation, was significantly reduced in the fructose group of female offspring. The activity of G6Pase, which plays a role in gluconeogenesis, was significantly enhanced in the liver of female offspring from fructose-fed dams. These changes were not observed in male offspring. In conclusion, we found that excessively high fructose intake during pregnancy may modulate the hepatic and hypothalamic AMPK signalling pathways in female offspring after birth.