M. Sokolovsky et al., LIGAND-SPECIFIC STIMULATION INHIBITION OF CAMP FORMATION BY A NOVEL ENDOTHELIN RECEPTOR SUBTYPE/, Biochemistry, 33(38), 1994, pp. 11417-11419
The possible involvement of a cAMP pathway in endothelin (ET) signal t
ransduction was explored using rat atrial slices. We show that ET-1 in
duces both stimulation and inhibition of cAMP formation, depending on
its concentration. Unexpectedly, the effects of ET-3 and of sarafotoxi
ns b and c (SRTX-b and SRTX-c) on this pathway differ from that of ET-
1. Moreover, we show that the ET-1-induced formation of cAMP results f
rom catecholamine release in a process mediated by a Ca2+ channel coup
led to a pertussis toxin sensitive G-protein. It is concluded that thi
s pathway is mediated by a new ET(A) receptor subtype (probably presyn
aptic), for which ET-1 is an agonist and ET-3, SRTX-b, and SRTX-c are
antagonists.