title: Mammary leptin synthesis, milk leptin and their putative physiological roles.
abstract: This paper reviews data on mammary leptin and leptin receptor gene expression as well as on blood and milk leptin levels during the pregnancy-lactation cycle in humans, rodents and ruminants, with the aim of better understanding milk leptin origin and functions. The few published papers report that leptin may be produced by different cell types in the mammary tissue, and may act as a paracrine factor on mammary epithelial cell proliferation, differentiation and/or apoptosis via adipose-epithelial and/or myoepithelial-epithelial cellular interactions. In addition to leptin synthesis, epithelial cells may transfer leptin from the blood, and these two mechanisms may account for the presence of leptin in the milk. The respective parts of these two processes remain to be determined, as well as the true milk leptin levels. Indeed, reported concentrations for milk leptin vary strongly according to species and mainly according to the milk fractions and the assay methods used. If leptin levels in milk (and specially colostrum) are found to be significant, this hormone could be involved in neonate physiology.
authors.affiliation: Unité de Recherche sur les Herbivores, Equipe Tissu Adipeux et Lipides du Lait, INRA, 63122 Saint-Genès-Champanelle, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Bonnet
authors.forename: Carole
authors.initials: C
authors.lastname: Delavaud
authors.forename: Karine
authors.initials: K
authors.lastname: Laud
authors.forename: Isabelle
authors.initials: I
authors.lastname: Gourdou
authors.forename: Christine
authors.initials: C
authors.lastname: Leroux
authors.forename: Jean
authors.initials: J
authors.lastname: Djiane
authors.forename: Yves
authors.initials: Y
authors.lastname: Chilliard
mesh_terms: D017667:Adipocytes / Q000378:metabolism*; D000818:Animals; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007774:Lactation / Q000502:physiology*; D020738:Leptin / Q000032:analysis / Q000096:biosynthesis* / Q000097:blood; D008321:Mammary Glands, Animal / Q000166:cytology / Q000502:physiology*; D008892:Milk / Q000737:chemistry* / Q000378:metabolism; D011247:Pregnancy; D011956:Receptors, Cell Surface / Q000096:biosynthesis; D054411:Receptors, Leptin; D012377:Rodentia / Q000502:physiology; D012418:Ruminants / Q000502:physiology
chemical_list: C515448:LEPR protein, human; D020738:Leptin; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin