RECEPTORS FOR ATRIAL-NATRIURETIC-PEPTIDE (ANP) AND CYCLIC-GMP RESPONSES IN HELA-CELLS

Cultured HeLa cells display specific binding sites for atrial natriuretic peptide (ANP). Studies with [125I] - (1-28) -rat ANP revealed the presence of a single class of high affinity dinding sites on HeLa cells: The apparent dissociation constant (Kd) was 5 nM and the maximal number was 29,000 sites/cell as derived from scatchard analysis. Furthermore, ANP elevates levels of cGMP in a dose dependent manner with an EC50 close to the Kd for [125I]ANP binding. ANP-mediated elevation of cellular cGMP leads to a significant reduction of bumetanide-sensitive Na+,K+,2Cl--cotransport in HeLa cells, studied by 22Na+ and 86Rb+ influx measurements. These data indicate (1) that distinct functionally active receptors for ANP are present on HeLa cells and (2) ANP influences the activity of Na+,K+,2Cl--cotransport in these cells. © 1990.