The contractile effects of endothelins on the smooth muscle of the rat prostate gland

• Published in: European journal of pharmacology Vol. 403; no. 1; pp. 139 - 145
• Main Authors: Salamoussa, Angela, Lau, Winnie A.K, Pennefather, Jocelyn N, Ventura, Sabatino
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2000; Elsevier
• Subjects: Animals; Biological and medical sciences; Bosentan; Dose-Response Relationship, Drug; Electric Stimulation; Endocrine pancreas; Endothelin; Endothelin ET A receptor; Endothelin Receptor Antagonists; Endothelin-1 - pharmacology; Endothelin-2 - pharmacology; Endothelin-3 - pharmacology; Endothelins - pharmacology; Fundamental and applied biological sciences. Psychology; Hormones. Régulation; In Vitro Techniques; Male; Muscle Contraction - drug effects; Muscle, Smooth - drug effects; Muscle, Smooth - physiology; Neuromuscular transmission; Oligopeptides - pharmacology; Peptides, Cyclic - pharmacology; Piperidines - pharmacology; Prostate; Prostate - drug effects; Prostate - physiology; Rat; Rats; Receptor, Endothelin A; Receptor, Endothelin B; Sulfonamides - pharmacology; Vasoconstrictor Agents - pharmacology; Vertebrates: endocrinology; Viper Venoms - pharmacology; Endothelin ET A receptor; Endothelin; Rat; Neuromuscular transmission; Prostate; Peptide hormone; Rodentia; Smooth muscle; Muscle contraction; In vitro; Biological activity; Vertebrata; Mammalia; Animal; Exocrine gland; Peptidergic receptor; Vasoconstrictor agent; Urogenital system
• DOI: 10.1016/S0014-2999(00)00580-X
• ISSN: 0014-2999

Endothelin-1 elicited tonic contractions of rat prostatic smooth muscle that were unaffected by prazosin (0.5 μM), tetrodotoxin (1 μM) or guanethidine (10 μM). The rank order of potency of the endothelin isopeptides was endothelin-1>endothelin-2≥endothelin-3. Sarafotoxin S6B was approximately equipotent with endothelin-1 in eliciting tonic contractions, but neither of the selective endothelin ET B receptor-agonists, sarafotoxin S6C (0.1 nM–0.3 μM) and BQ3020 (Ac-[Ala 11,15]endothelin-1(6–21); 0.1 nM–0.3 μM), affected prostatic smooth muscle tone. The selective endothelin ET A receptor antagonist, BQ123 (cyclo( d-Asp- l-Pro- d-Val- l-Leu- d-Trp; 1 μM), attenuated responses to endothelin-1, -2 and -3, while the non-selective endothelin receptor antagonist bosentan (1 μM) and the selective endothelin ET B receptor antagonist BQ788, (Dmpc-γ-MeLeu 9- d-Trp(l-CO 2CH 3)- d-Nle-OH; 1 μM) attenuated responses to endothelin-3 only. Contractions induced by exogenous administration of noradrenaline were unaffected by preincubation of tissues in BQ123 (1 μM) indicating the selectivity of this antagonist. These data suggest that endothelins mediate contractions of the rat prostate by action at endothelin ET A receptors.