INTERACTIONS OF ATRIAL-NATRIURETIC-PEPTIDE WITH A7R5 CELLS

The interactions of Atrial Natriuretic Peptide with its receptors were investigated with the vascular smooth muscle cells from the A7r5 cell line. Displacement experiments of [I-125]rat-Atrial Natriuretic Pepti de by rat-Atrial Natriuretic Peptide revealed a single class of recept ors with a Kd = 0.21 +/- 0.08 nM and a Bmax = of 35 +/- 16 fmol/mg of protein. Furthermore, the complex [I-125]r-Atrial Natriuretic Peptide was internalised by a heatsensitive process. Finally, Atrial Natriuret ic Peptide increased cyclic Guanosyl 3',5' Mono Phosphate in a time de pendent and dose dependent way, a concentration of 0.1 mu M increasing cyclic Guanosyl 3',5' Mono Phosphate level by a factor of 8.3 times w hen compared to basal level. (C) 1994 Academic Press, Inc.