title: Hypoadiponectinemia in lean lactating women: Prolactin inhibits adiponectin secretion from human adipocytes.
abstract: Adiponectin is an adipocyte-derived hormone involved in glucose, lipid and energy metabolism. A low plasma adiponectin concentration is associated with insulin resistance, obesity and atherosclerosis. In women, energy homeostasis is remarkably changed during gestation and lactation in order to supply sufficient nutrition for a fetus or newborn. In this study we aimed to elucidate the physiological impact of gestation and lactation on the plasma adiponectin levels and the influence of reproduction-related hormones on adiponectin secretion. We studied the longitudinal changes in plasma adiponectin concentration during pregnancy (1st, 2nd and 3rd trimester) and lactation (3 days and 1 month after the delivery) in lean healthy women (n = 22). The plasma adiponectin level declined slightly as the pregnancy advanced and reached its lowest level during lactation (12.25 +/- 0.182 microg/ml at early pregnancy vs. 6.88 +/- 0.375 microg/ml at 3 days postpartum, p < 0.001). In order to investigate the role of the lactogenic hormone prolactin in the decrease of plasma adiponectin levels during lactation, we further performed in vitro experiments using human primary cultured adipocytes. Western blotting of the adipocyte lysate and ELISA of the culture medium revealed that exogenous prolactin inhibited both production and secretion of adiponectin in a dose-dependent manner. Our results thus suggests that prolactin affects the regulation of maternal metabolism through suppression of adiponectin.
authors.affiliation: Department of Obstetrics, Gynecology and Molecular Reproductive Science, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Mikiko
authors.initials: M
authors.lastname: Asai-Sato
authors.forename: Machi
authors.initials: M
authors.lastname: Okamoto
authors.forename: Masaya
authors.initials: M
authors.lastname: Endo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshida
authors.forename: Mariko
authors.initials: M
authors.lastname: Murase
authors.forename: Mario
authors.initials: M
authors.lastname: Ikeda
authors.forename: Hideya
authors.initials: H
authors.lastname: Sakakibara
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Takahashi
authors.forename: Fumiki
authors.initials: F
authors.lastname: Hirahara
mesh_terms: D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism; D052242:Adiponectin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000328:Adult; D005260:Female; D006801:Humans; D007564:Japan; D007774:Lactation / Q000187:drug effects / Q000502:physiology*; D008137:Longitudinal Studies; D011247:Pregnancy; D011388:Prolactin / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011981:Receptors, Prolactin / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D052242:Adiponectin; D012333:RNA, Messenger; D011981:Receptors, Prolactin; D011388:Prolactin