Details

Autor(en) / Beteiligte

• Oshita, Masafumi
• Hiraoka, Yasuko
• Morikawa, Kouji
• Nagata, Osamu
• Hahn, Klaus J.
• Okada, Kenichiro
• Taniguchi, Takanobu
• Muramatsu, Ikunobu

Titel

Characterization of the endothelin receptor subtypes in human prostate

Ist Teil von

• Japanese Journal of Pharmacology, 1999, Vol.79 (suppl.1), p.133-133

Ort / Verlag

The Japanese Pharmacological Society

Erscheinungsjahr

1999

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• Endothelin receptor subtypes in human prostate from BPH patients were investigated in binding and functional studies. In receptor binding experiments, LU135252 (ET_A antagonist), LU224332 (Mixed ET_A & ET_B antagonist) and BQ788 (ET_B antagonist) inhibited the binding of [^^125 I]-endothelin-1 (ET-1) to the membranes of human prostate with a rank order of LU135252 = LU224332 > BQ788, indicating that the ET_A receptor is the predominant subtype. In human prostate strips, ET-1 induced a concentration-dependent contractile response and its potency was more than 10 times stronger than that of noradrenaline. LU135252 (10 μM) and LU224332 (10 μM) strongly inhibited the contractile response to ET-1 with the same potency. But 10 μM of BQ788 caused only a slight inhibition. The predominant inhibition of ET-1-induced contractile response via ET_A antagonism is in agreement with the dominance of this receptor in the binding experiment. Sarafotoxin S6c (ET_B agonist) also produced a contractile response, which was potently inhibited by LU224332 and BQ788, but only slightly by LU135252. Taking the low density of ET_B receptors on prostate membranes into account, the high efficacy of Sarafotoxin S6c needs further investigations.