Differential distribution of endothelin receptor subtypes in placentae from normal and growth-restricted pregnancies.
Placenta
; 18(2-3): 173-80, 1997.
Article
em En
| MEDLINE
| ID: mdl-9089779
ABSTRACT
The endothelins (ETs) are potent vasoconstrictor peptides that bind to two distinct receptors, ETA and ETB. This study compares the localization of ETA and ETB receptors in placentae complicated by intrauterine growth retardation (IUGR) and abnormal umbilical Doppler waveform, gestationally matched controls, fetuses that were small for gestational age (SGA), and normal term placentae. Quantitative autoradiography was performed using ETA and ETB subtype-selective ligands. Both ETA and ETB receptors were expressed in the human placenta. Gestational and fetal size effects on the receptor density within stem villi were found, but no effect of abnormal placental blood flow could be demonstrated. A distinct spatial distribution of receptor subtypes within the placenta was observed. Smooth muscle cells expressed both receptors with ETA expression predominant in the proximal regions of the villous tree and ETB abundant in the periphery and decidua. Both receptors were also expressed at lower density on paravascular stromal cells in stem villi. Although these data do not demonstrate aberrant localization of ET receptors in IUGR and SGA placentae, the spatially distinct distribution of ET receptors in the human placenta suggests that ETs play a role in modulation of placental blood flow.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Placenta
/
Receptores de Endotelina
/
Retardo do Crescimento Fetal
Limite:
Adult
/
Female
/
Humans
/
Pregnancy
Idioma:
En
Revista:
Placenta
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Reino Unido