Localization of alpha(2)-macroglobulin receptor/low-density lipoprotein receptor in third-trimester human placentas: A preliminary immunohistochemical study

The alpha (2)-macroglobulin receptor/low-densitiy lipoprotein receptor-rela ted protein (alpha (2)-M-R/LRP) is involved in a variety of transcellular t ransportations, e.g. of apolipoprotein E, and represents an inhibitor of pr oteinases. After creation of monoclonal antibodies of the alpha- and beta - subunits of the alpha (2)-M-R/LRP and its receptor-associated protein, we h ave tested their distribution in five 3rd-trimester placentas, using cryose ctions, immunohistochemically and by immunofluorescence. All three monoclon al antibodies showed positive staining in villous and extravillous cytotrop hoblasts and intravillous vessels, but not in syncytiotrophoblasts. Thus, a lpha (2)-M-R/LRP plays a possible role in the transplacental nutritional tr ansportation process. It is necessary to search the distribution of alpha ( 2)-M-R/LRP under pathological conditions, like fetal growth retardation and preeclampsia. Copyright (C) 2001 S. Karger AG, Basel