TY - JOUR
T1 - A novel subtype of endothelin B receptor mediating contraction in swine pulmonary vein
AU - Sudjarwo, Sri Agus
AU - Hori, Masatoshi
AU - Takai, Michihiro
AU - Urade, Yoshihiro
AU - Okada, Toshikazu
AU - Karaki, Hideaki
N1 - Funding Information:
We are grateful to Dr. A. F. James, Ciba Geigy Japan, for helpful discussion and critical reading of the manuscript and to Fujisawa Pharmaceutical Co. for the generous gift of FR139317. This work was supported by Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture, Japan.
PY - 1993
Y1 - 1993
N2 - Effects of agonists and antagonists of endothelin (ET) receptors were examined in swine pulmonary artery and vein and in rabbit saphenous vein. ET-1, but not ETB receptor agonists, sarafotoxin S6c (STXc) and IRL 1620, induced contraction in pulmonary artery. This effect was inhibited by the ETA receptor antagonists, BQ-123 and FR139317, but not by the ETB receptor antagonist, IRL 1038. Pulmonary artery precontracted by norepinephrine was relaxed by ET-3 in an endothelium-dependent manner. This relaxation was inhibited by IRL 1038 but not by BQ-123. In pulmonary vein, ET-1, ET-3, STXc and IRL 1620 induced contractions at a similar concentration range. ET-1 induced contraction also in saphenous vein. These contractions were not inhibited by BQ-123, FR139317 or IRL 1038. These results suggest that the isopeptide-selective ETA receptor mediates contraction in swine pulmonary artery whereas the isopeptide-nonselective ETB receptor mediates release of endothelium-derived relaxing factor. In contrast, contractions in the veins may be mediated by a novel subtype of isopeptide-nonselective ETB receptor which is not inhibited by IRL 1038.
AB - Effects of agonists and antagonists of endothelin (ET) receptors were examined in swine pulmonary artery and vein and in rabbit saphenous vein. ET-1, but not ETB receptor agonists, sarafotoxin S6c (STXc) and IRL 1620, induced contraction in pulmonary artery. This effect was inhibited by the ETA receptor antagonists, BQ-123 and FR139317, but not by the ETB receptor antagonist, IRL 1038. Pulmonary artery precontracted by norepinephrine was relaxed by ET-3 in an endothelium-dependent manner. This relaxation was inhibited by IRL 1038 but not by BQ-123. In pulmonary vein, ET-1, ET-3, STXc and IRL 1620 induced contractions at a similar concentration range. ET-1 induced contraction also in saphenous vein. These contractions were not inhibited by BQ-123, FR139317 or IRL 1038. These results suggest that the isopeptide-selective ETA receptor mediates contraction in swine pulmonary artery whereas the isopeptide-nonselective ETB receptor mediates release of endothelium-derived relaxing factor. In contrast, contractions in the veins may be mediated by a novel subtype of isopeptide-nonselective ETB receptor which is not inhibited by IRL 1038.
UR - http://www.scopus.com/inward/record.url?scp=0027300076&partnerID=8YFLogxK
U2 - 10.1016/0024-3205(93)90647-L
DO - 10.1016/0024-3205(93)90647-L
M3 - Article
C2 - 8336522
AN - SCOPUS:0027300076
SN - 0024-3205
VL - 53
SP - 431
EP - 437
JO - Life Sciences
JF - Life Sciences
IS - 5
ER -