Effects of stanniocalcin hormones on rat hepatic glucose homeostasis under fed and fasted conditions.

To test the hypothesis of conservation of stanniocalcin 1 and 2 (STC-1; STC-2) metabolic functions in vertebrates, we performed an in vitro study to determine if these hormones are implicated in regulation of the gluconeogenesis pathway, glycogen synthesis, and 14C-glucose conversion to 14CO2 in livers from fed and fasting rats (Rattus norvegicus). Stc1 and Stc2 gene expressions increased in the liver after fasting. STC-1 participated in the regulation of the hepatic gluconeogenesis pathway in rats when the precursor was 14C-lactate. STC-2 demonstrated variational signaling on rat hepatic gluconeogenesis activity and Pck1 gene expression, decreasing levels in the fed state when the substrate was 14C-alanine and increasing levels during fasting when the substrate was 14C-lactate. At the concentrations used in this study, STC-1 and STC-2 did not affect glycogen concentration and synthesis from 14C-glucose or 14C-glucose conversion to 14CO2 in the livers from fed or fasting rats. These findings highlight the role of stanniocalcins in the hepatic gluconeogenesis pathway in mammals and confirm the conservation of STC-1 and STC-2 metabolic functions in the vertebrates.

Late pregnancy maternal naringin supplementation affects the mitochondria in the cerebellum of Wistar rat offspring via sirtuin 3 and AKT.

Dietary polyphenol consumption is associated with a wide range of neuroprotective effects by improving mitochondrial function and signaling. Consequently, the use of polyphenol supplementation has been investigated as an approach to prevent neurodevelopmental diseases during gestation; however, the data obtained are still very inconclusive, mostly because of the difficulty of choosing the correct doses and period of administration to properly prevent neurodegenerative diseases without undermining normal brain development. Thus, we aimed to evaluate the effect of naringin supplementation during the third week of gestation on mitochondrial health and signaling in the cerebellum of 21-day-old offspring. The offspring born to naringin-supplemented dams displayed higher mitochondrial mass, membrane potential, and superoxide content in the cerebellum without protein oxidative damage. Such alterations were associated with dynamin-related protein 1 (DRP1) and phosphorylated AKT (p-AKT) downregulation, whereas the sirtuin 3 (SIRT3) levels were strongly upregulated. Our findings suggest that high dietary polyphenol supplementation during gestation may reduce mitochondrial fission and affect mitochondrial dynamics even 3 weeks after delivery via SIRT3 and p-AKT. Although the offspring born to naringin dams did not present neurobehavioral defects, the mitochondrial alterations elicited by naringin may potentially interfere during neurodevelopment and need to be further investigated.