Characterization of specific receptors for atrial natriuretic factor in bovine adrenal zona glomerulosa

摘要: Abstract We have recently shown that synthetic rat atrial natriuretic factor (ANF) directly inhibits mineralocorticoid and glucocorticoid secretion in cultured bovine adrenal cells with a potency of 100 pM. [ 125 I]iodo-ANF was used the present study to characterize potential receptor sites zona glomerulosa membranes. ANF binds class high affinity binding pK 10.2 density 1.3 pmol/mg protein. Detailed competition curves document also second lower 8.5. Nonspecific amounts less than 10% at concentrations High is reversible half-time association 15 minutes 25 pM dissociation 140 minutes. Monovalent cations Na, Li K equipotently enhance specific binding. Divalent Mg, Ca Mn increase binding, being most active cation. No effect guanine nucleotide could be detected on The very not inhibited by 1 μM angiotensin II, ACTH, VIP, somatostatin, Leu-enkephalin, dynorphin or N-terminal POMC. fragment ANF-(1–16) completely inactive. Reduction disulfide bridge inactivates peptide. This enabled development highly radio-receptor assay for minimum detectable dose 2 femtomoles. results involved potent inhibitory steroidogenesis indicate provide sensitive system studying discovered factor.