The in vitro effect of progesterone on the orexin system in porcine uterine tissues during early pregnancy.

The results indicate that P4 could regulate the expression of the orexin system in the porcine uterus during early pregnancy, which suggests the presence of a local feedback loop that could play an important role in the regulation of maternal metabolism during pregnancy. The findings may contribute to the existing knowledge of the mechanisms linking maternal energy metabolism with the regulation of the reproductive system during pregnancy.