title: Suppression of atrial natriuretic peptide (ANP) receptor recovery from homologous down-regulation by 8-bromo-cGMP in endothelial cells.
abstract: In a previous study we reported that cyclic GMP (cGMP) selectively down-regulates the atrial natriuretic peptide clearance receptor (C-ANP receptor) in the cultured bovine pulmonary artery endothelial (CPAE) cell line. Our efforts in the current study are directed towards determining the effects of cGMP on C-ANP receptor recycling and de novo synthesis following homologous down-regulation by atriopeptin III (APIII, rat ANP 103-126). [125I]APIII binding to CPAE cells was decreased to 45.3 +/- 1.0% of control following the pretreatment with 100 nM APIII for 24 h. After the removal of APIII, the decreased [125I]APIII binding gradually recovered up to 68.8 +/- 1.8% of control for 24 h: a 'long-term recovery'. When CPAE cells were pretreated with 1 nM APIII for 30 min, [125I]APIII binding was also decreased to 62.6 +/- 2.6% of control. Following the removal of APIII, the decrease in [125I]APIII binding quickly recovered to 87.7 +/- 2.7% of control for 1 h: a 'short-term recovery'. 8-bromo-cGMP suppressed the long-term recovery of ANP receptor in a dose-dependent manner, while it had no effect on the short-term recovery. Both actinomycin D (1 ng/ml) and cycloheximide (10 ng/ml) significantly (P less than 0.01) suppressed the long-term recovery, but failed to affect the short-term recovery, whereas, the short-term recovery was significantly (P less than 0.01) inhibited by either 10 mM NH4Cl or 0.2 mM chloroquine which inhibits the recycling of internalized ANP receptor. These findings suggest that new ANP receptor synthesis is necessary for long-term but not for short-term recovery.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Monsanto Corporate Research, St. Louis, MO 63167.
authors.forename: J
authors.initials: J
authors.lastname: Kato
authors.forename: M G
authors.initials: MG
authors.lastname: Currie
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology*; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D015536:Down-Regulation; D004727:Endothelium / Q000166:cytology / Q000378:metabolism*; D007457:Iodine Radioisotopes; D011485:Protein Binding / Q000187:drug effects*; D011869:Radioligand Assay
chemical_list: D007457:Iodine Radioisotopes; D015124:8-Bromo Cyclic Adenosine Monophosphate; D009320:Atrial Natriuretic Factor