Et-1 and Et-3 actions mediated by cloned ETA endothelin receptors exhibit different sensitivities to BQ-123.
Et-1 and Et-3 activate phospholipase C in fibroblasts expressing cloned ETA receptors of bovine, rat and human origins. BQ-123 competitively antagonizes both responses but Et-3 actions are 10 times more sensitive to BQ-123 than Et-1 actions. It is suggested that differential sensitivity to BQ-123 is an intrinsic property of Et-1 and Et-3 activated ETA receptors and that there is no need to postulate the existence of new ETA receptor isoforms to account for singular actions of BQ-123.
Gresser
O
O
Institut de Pharmacologie Moléculaire et Cellulaire du CNRS, Valbonne, France.
Chayard
D
D
Herbert
D
D
Cousin
M A
MA
Le Moullec
J M
JM
Bouattane
F
F
Guedin
D
D
Frelin
C
C
D000818:Animals; D016466:CHO Cells; D002417:Cattle; D002460:Cell Line; D003001:Cloning, Molecular; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D065128:Endothelin Receptor Antagonists; D016232:Endothelins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007700:Kinetics; D010456:Peptides, Cyclic / Q000494:pharmacology*; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D051381:Rats; D044022:Receptor, Endothelin A; D017466:Receptors, Endothelin / Q000096:biosynthesis / Q000502:physiology*; D011994:Recombinant Proteins / Q000187:drug effects / Q000378:metabolism; D010738:Type C Phospholipases / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism
D065128:Endothelin Receptor Antagonists; D016232:Endothelins; D010456:Peptides, Cyclic; D044022:Receptor, Endothelin A; D017466:Receptors, Endothelin; D011994:Recombinant Proteins; D010738:Type C Phospholipases; C072247:cyclo(Trp-Asp-Pro-Val-Leu)