Roles of Leptin and Ghrelin during the Perinatal Period

Abstract

The changes in the leptin and ghrelin concentrations during the perinatal period are reviewed and their possible roles are discussed. In humans, leptin concentrations in cord blood were positively correlated with the birth weight and Kaup index. Most leptin was derived from fetal adipocytes, although the placenta has also been shown to make a contribution. An apparent gender difference in these concentrations (male<female) has been observed. After birth, these concentrations rapidly decreased and then gradually increased during the neonatal period. The developmental changes in the expression and localization of OB-Rb in the rat brain suggested that the setting point of leptin signal transduction changes with age during the neonatal period. The ghrelin concentration in cord blood was inversely correlated with birth weight, placental weight and the IGF-I concentration. IGF-I was a predominant factor that was correlated with the ghrelin concentration. The placenta seemed to contribute the ghrelin concentration in cord blood. During the early neonatal period, the ghrelin concentration significantly increased. The present results suggest that they might cooperatively regulate the energy balance during the perinatal period, and their expression in the placenta might contribute to the regulation of feto-maternal energy transport.