Z. Shragalevine et M. Sokolovsky, CGMP FORMATION IN RAT ATRIAL SLICES IS LIGAND AND ENDOTHELIN RECEPTORSUBTYPE-SPECIFIC, Circulation research, 78(3), 1996, pp. 424-430
Involvement of a cGMP pathway in signal transduction stimulated by end
othelins (ETs) and sarafotoxins (SRTXs) was examined in rat atrial sli
ces. These peptides activated different receptor-binding sites (ET-1 a
nd SRTX-b reacted with the picomolar binding sites of the ET(A) recept
or, and ET-3 and SRTX-c reacted with the nanomolar binding sites of th
e ET(B) receptor) to produce cGMP. ET-1 and SRTX-b stimulated an incre
ase in cGMP levels via a Ca2(+)-dependent NO pathway involving a pertu
ssis toxin-insensitive protein, whereas ET-3 and SRTX-c elevated cGMP
levels via a Ca2+-independent CO pathway involving a pertussis toxin-s
ensitive G protein. These results can best be explained in terms of fo
rmation of different ligand-receptor-G-protein complexes. The ligands
had no effect on ventricular slices, indicating that these signal tran
sduction mechanisms are unique to the atria.