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 C-glucose conversion to CO 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 C-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 C-alanine and increasing levels during fasting when the substrate was C-lactate. At the concentrations used in this study, STC-1 and STC-2 did not affect glycogen concentration and synthesis from C-glucose or C-glucose conversion to CO 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.