Characterization of the endothelin receptor subtypes in human prostate

Citation
Y. Hiraoka et al., Characterization of the endothelin receptor subtypes in human prostate, J CARDIO PH, 36, 2000, pp. S252-S254
Citations number
8
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Journal title
JOURNAL OF CARDIOVASCULAR PHARMACOLOGY
ISSN journal
0160-2446 → ACNP
Volume
36
Year of publication
2000
Supplement
1
Pages
S252 - S254
Database
ISI
SICI code
0160-2446(2000)36:<S252:COTERS>2.0.ZU;2-A
Abstract
Endothelin (ET) receptor subtypes in human prostate with benign prostatic h yperplasia were investigated by binding and functional studies. In the disp lacement experiment, LU224332 [endothelin-A/-B (ETA/ETB) nonselective antag onist] competed for [I-125]ET-1 binding with a monophasic curve. On the oth er hand, LU135252 (ETA-selective antagonist) and sarafotoxin S6c (S6c, ETB- selective agonist) competed for [I-125]ET-1 binding with shallow and biphas ic curves. The analysis of the displacement curves for LU135252 and S6c sho wed that both ETA and ETB subtypes coexist but that ET, is the dominantly e xpressed receptor. In human prostate strips, 10 muM of both LU135252 and LU 224332 strongly inhibited the contractile response to ET-1 with equal poten cy. However, 10 muM of BQ788 (ETB-selective antagonist) did not show a clea r inhibition. S6c also produced a contractile response, which was potently inhibited by LU224332 or BQ788, and slightly suppressed by LU135252. These results suggest that in human prostate both ETA and ETB subtypes are functi onal receptors mediating contraction, but that ET-1-mediated contractions a re predominantly mediated by activation of dominant receptor subtype, ETA.