TY - JOUR
T1 - Subtypes of Endothelin ETA and ETB Receptors Mediating Venous Smooth Muscle Contraction
AU - Sudjarwo, Agus
AU - Hori, Masatoshi
AU - Tanaka, Takeo
AU - Matsuda, Yuzuru
AU - Okada, Toshikazu
AU - Karaki, Hideaki
PY - 1994
Y1 - 1994
N2 - In rabbit saphenous vein, endothelin (ET)-1 and ET-3 induced sustained contractions whereas the selective agonists of the ETB receptor, sarafotoxin S6c (STXc) and IRL 1620, induced transient contractions. In the presence of an ETA antagonist, BQ-123, contractions induced by ET-1, STXc and IRL 1620 did not change whereas ET-3 induced only transient contraction. The ETB antagonists, RES-701-1 and IRL 1038, only weakly antagonized the effects of these stimulants. In the muscle pretreated with STXc, neither STXc nor IRL 1620 was effective whereas ET-3 induced sustained contraction at higher concentrations than ET-1. In the muscle pretreated with STXc, BQ-123 weakly antagonized the effect of ET-1 and abolished the effect of ET-3. These results suggest that there are two types of ET receptors; less tachyphylactic and isopeptide-selective ETA receptor, and tachyphylactic and isopeptide-nonselective ETB receptor. The ETA receptors may be further classified as a BQ-123-sensitive ETA1 and a BQ-123-insensitive ETA2 subtypes. The ETB receptors may also be subclassified as the ETB1 and ETB2 subtypes based on the sensitivity to the ETB antagonists.
AB - In rabbit saphenous vein, endothelin (ET)-1 and ET-3 induced sustained contractions whereas the selective agonists of the ETB receptor, sarafotoxin S6c (STXc) and IRL 1620, induced transient contractions. In the presence of an ETA antagonist, BQ-123, contractions induced by ET-1, STXc and IRL 1620 did not change whereas ET-3 induced only transient contraction. The ETB antagonists, RES-701-1 and IRL 1038, only weakly antagonized the effects of these stimulants. In the muscle pretreated with STXc, neither STXc nor IRL 1620 was effective whereas ET-3 induced sustained contraction at higher concentrations than ET-1. In the muscle pretreated with STXc, BQ-123 weakly antagonized the effect of ET-1 and abolished the effect of ET-3. These results suggest that there are two types of ET receptors; less tachyphylactic and isopeptide-selective ETA receptor, and tachyphylactic and isopeptide-nonselective ETB receptor. The ETA receptors may be further classified as a BQ-123-sensitive ETA1 and a BQ-123-insensitive ETA2 subtypes. The ETB receptors may also be subclassified as the ETB1 and ETB2 subtypes based on the sensitivity to the ETB antagonists.
UR - http://www.scopus.com/inward/record.url?scp=0028177859&partnerID=8YFLogxK
U2 - 10.1006/bbrc.1994.1494
DO - 10.1006/bbrc.1994.1494
M3 - Article
C2 - 8166738
AN - SCOPUS:0028177859
SN - 0006-291X
VL - 200
SP - 627
EP - 633
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -