Endothelin receptor subtypes are coupled to adenylate cyclase via different guanyl nucleotide-binding proteins in vasculature.
We have studied whether endothelin (ET) isopeptides have any effects on adenylate cyclase activity via different guanyl nucleotide-binding proteins (G-proteins) in cultured rat vascular smooth muscle cells (VSMC) and bovine endothelial cells (EC). Northern blot analysis clearly demonstrated gene expression of ETA receptors in VSMC and ETB receptors in EC. ET-1 dose-dependently (10(-9)-10(-6) M) stimulated cAMP formation in VSMC, whose effect was inhibited completely by ETA receptor antagonist (BQ-123) but not by indomethacin or quinacrine. The ET-1-induced cAMP formation was additive with isoproterenol but not with cholera toxin. In contrast, ET-3 and ETB receptor agonist (BQ-3020) dose-dependently (10(-9)-10(-6) M) inhibited forskolin-stimulated cAMP formation in EC, whose effect was completely abolished by pertussis toxin. Cholera toxin ADP ribosylated 45- and 52-kilodalton proteins in VSMC, whereas pertussis toxin ADP ribosylated the 41-kilodalton protein in EC. These data suggest that, in addition to phospholipase C via Gq, ETA and ETB receptor subtypes are functionally coupled to adenylate cyclase, possibly via Gs in VSMC and Gi in EC, respectively.
Eguchi
S
S
Second Department of Internal Medicine, Tokyo Medical and Dental University, Japan.
Hirata
Y
Y
Imai
T
T
Marumo
F
F
D037361:Adenylate Cyclase Toxin; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002417:Cattle; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D015342:DNA Probes; D004305:Dose-Response Relationship, Drug; D065128:Endothelin Receptor Antagonists; D016232:Endothelins / Q000378:metabolism / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D007213:Indomethacin / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides; D010456:Peptides, Cyclic / Q000494:pharmacology; D037342:Pertussis Toxin; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D011796:Quinacrine / Q000494:pharmacology; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger; D051381:Rats; D017466:Receptors, Endothelin / Q000235:genetics / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D037361:Adenylate Cyclase Toxin; D015342:DNA Probes; D065128:Endothelin Receptor Antagonists; D016232:Endothelins; D009838:Oligodeoxyribonucleotides; D010456:Peptides, Cyclic; D012333:RNA, Messenger; D017466:Receptors, Endothelin; D010566:Virulence Factors, Bordetella; D011061:Poly A; D012313:RNA; D000242:Cyclic AMP; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D011796:Quinacrine; D007545:Isoproterenol; C072247:cyclo(Trp-Asp-Pro-Val-Leu); D007213:Indomethacin