Natriuretic peptide receptors in the fetal rat.
In vitro autoradiography of rat fetuses from embryonic days 12-19 (E12-E19) showed widespread high-affinity specific binding sites for natriuretic peptides. The sites on E16 somites avidly bound C-type natriuretic peptide [CNP-(1-22)] as well as C-ANP, a synthetic ligand that selects the C-type natriuretic peptide receptor (NPR-C). Most somitic binding sites had high affinity for atrial natriuretic peptide [ANP-(1-28)], confirming their resemblance to NPR-C. A few had a lower apparent affinity for ANP-(1-28), suggesting that they might be NPR-B. CNP-(1-22) was more powerful than ANP-(1-28) as an agonist of guanosine 3',5'-cyclic monophosphate production in somites, and ATP augmented the action of CNP-(1-22). These observations further suggest the presence of NPR-B. However, with cross-linking of 3-[125I]iodo-0-tyrosyl rat CNP-(1-22) to somitic membranes followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, only a single 64-kDa binding protein was detected under reducing conditions. This is not consistent with intact approximately 120-kDa NPR-B. In vitro autoradiography of the binding of natriuretic peptides to E16 liver implied the presence of NPR-A and NPR-C-like receptors. Hepatic guanosine 3',5'-cyclic monophosphate production was most powerfully stimulated by ANP-(1-28), as expected for NPR-A. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis also identified NPR-A and NPR-C-like proteins in E16 hepatic membranes. Thus different NPRs are expressed by specific fetal tissues. This may be developmentally significant.
Brown
J
J
Physiological Laboratory, Cambridge, United Kingdom.
Zuo
Z
Z
D000818:Animals; D001345:Autoradiography; D003432:Cross-Linking Reagents; D006152:Cyclic GMP / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005333:Fetus / Q000378:metabolism*; D008099:Liver / Q000196:embryology; D045283:Natriuretic Agents / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface / Q000378:metabolism*
D003432:Cross-Linking Reagents; D045283:Natriuretic Agents; D011956:Receptors, Cell Surface; D006152:Cyclic GMP