Salas S P, Power R F, Singleton A, Wharton J, Polak J M, Brown J
Royal Postgraduate Medical School, London, United Kingdom.
Am J Physiol. 1991 Sep;261(3 Pt 2):R633-8. doi: 10.1152/ajpregu.1991.261.3.R633.
The distributions of atrial natriuretic peptide (ANP) clearance receptors in human umbilical cord and placenta were investigated by using des[Gln18,Ser19,Gly20,Leu21,Gly22]ANP-(4-2 3) (C-ANP) as a specific ligand of this receptor to displace bound alpha-125I-labeled ANP. alpha-125I-ANP bound reversibly to umbilical venous and arterial intima and to fetal placental and maternal decidual tissues, with dissociation constants of 1.24 +/- 0.51, 0.58 +/- 0.19, 1.86 +/- 0.51, and 1.07 +/- 0.25 mM, respectively. Binding was reversed by 1 microM unlabeled alpha-ANP but not by unrelated peptides such as gastrin. The 1 microM C-ANP displaced bound alpha-125I-ANP from the intima of umbilical artery but not that of the vein. The specific reversible binding of alpha-125I-ANP to placental decidua but not to fetal placenta was also displaced by 1 microM C-ANP. Therefore high-affinity binding sites for alpha-ANP on the intima of the umbilical artery and on placental decidua differ from those on the umbilical vein and on fetal placental tissue; the binding sites of the intima of the umbilical artery and of the decidua in humans are consistent with clearance receptors for alpha-ANP.
采用去[Gln18,Ser19,Gly20,Leu21,Gly22]心房钠尿肽-(4 - 23)(C - ANP)作为该受体的特异性配体来置换结合的α - 125I标记心房钠尿肽，研究了心房钠尿肽(ANP)清除受体在人脐带和胎盘中的分布。α - 125I - ANP与脐静脉和动脉内膜以及胎儿胎盘和母体蜕膜组织可逆性结合，解离常数分别为1.24±0.51、0.58±0.19、1.86±0.51和1.07±0.25 mM。1 μM未标记的α - ANP可使结合逆转，但胃泌素等无关肽则不能。1 μM C - ANP可从脐动脉内膜置换结合的α - 125I - ANP，但不能从静脉内膜置换。1 μM C - ANP也可置换α - 125I - ANP与胎盘蜕膜而非胎儿胎盘的特异性可逆结合。因此，脐动脉内膜和胎盘蜕膜上α - ANP的高亲和力结合位点与脐静脉和胎儿胎盘组织上的不同；人脐动脉内膜和蜕膜的结合位点与α - ANP的清除受体一致。
