title: Placental vessel adaptation during gestation and to high altitude: changes in diameter and perivascular cell coverage.
abstract: The objective of this study was to determine how human placental vascular structures change during gestation and whether this would be altered by external factors such as reduced ambient oxygen. To achieve this, several experiments were carried out: Vessel profile diameter was measured and the presence of perivascular cells (pericytes or smooth muscle cells) noted. This was carried out in normal human first trimester and term placentae, and in term placentae obtained from high altitude and an ethnically matched lowland population. In addition, to characterize endothelial cells in human placenta a panel of endothelial markers anti-CD 105, CD31, CD34, Von Willebrand factor (vWF), Ulex europaeus agglutinin 1 (UEA I), Peanut agglutinin (PNA), Dolichos biflorus agglutinin (DBA) and Bandeieraea simplicifolia agglutinin 1 (BS 1) was used. The proportion of vessels associated with perivascular cells rises during gestation from 37 per cent in the first trimester to 63 per cent at term (P<0.0001) and vessels with perivascular cells have a larger median diameter at term. In placentae obtained at high altitude, the vessels are dilated and are less frequently associated with perivascular cells. The absence of perivascular cells may allow remodelling of capillaries and this is likely to be physiological important in the first trimester but also under physiological or pathological stress.
authors.affiliation: Reproductive Molecular Research Group, Department of Pathology, University of Cambridge, Cambridge, CB2 2SW, UK.
authors.forename: E G
authors.initials: EG
authors.lastname: Zhang
authors.forename: G J
authors.initials: GJ
authors.lastname: Burton
authors.forename: S K
authors.initials: SK
authors.lastname: Smith
authors.forename: D S
authors.initials: DS
authors.lastname: Charnock-Jones
mesh_terms: D000199:Actins / Q000032:analysis; D000222:Adaptation, Physiological; D000531:Altitude; D015703:Antigens, CD; D018952:Antigens, CD34 / Q000032:analysis; D001808:Blood Vessels / Q000166:cytology* / Q000502:physiology*; D000071063:Endoglin; D004730:Endothelium, Vascular / Q000737:chemistry / Q000166:cytology; D005260:Female; D005865:Gestational Age; D006801:Humans; D007150:Immunohistochemistry; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D019887:Peanut Agglutinin / Q000032:analysis; D010920:Placenta / Q000098:blood supply*; D037121:Plant Lectins / Q000032:analysis; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis; D011247:Pregnancy; D011956:Receptors, Cell Surface; D019010:Vascular Cell Adhesion Molecule-1 / Q000032:analysis; D014664:Vasodilation; D014841:von Willebrand Factor / Q000032:analysis
chemical_list: D000199:Actins; D015703:Antigens, CD; D018952:Antigens, CD34; C064206:ENG protein, human; D000071063:Endoglin; C045475:Griffonia simplicifolia lectins; D019887:Peanut Agglutinin; D037121:Plant Lectins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011956:Receptors, Cell Surface; C036850:Ulex europaeus lectins; D019010:Vascular Cell Adhesion Molecule-1; C036554:dolichos biflorus agglutinin; D014841:von Willebrand Factor