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An in Vivo Evaluation of Alpha Adrenergic Receptors in Canine Prostate

1989; Lippincott Williams & Wilkins; Volume: 141; Issue: 5 Linguagem: Inglês

10.1016/s0022-5347(17)41227-4

1527-3792

William J. Somers, Diane Felsen, Ting‐Chao Chou, D. Marion, Chris E. Chernesky, E. Darracott Vaughan,

Veterinary Pharmacology and Anesthesia

No AccessJournal of Urology1 May 1989An in Vivo Evaluation of Alpha Adrenergic Receptors in Canine Prostate William J. Somers, Diane felsen, Ting-Chao Chou, Donald N. Marion, Chris E. Chernesky, and E. Darracott Vaughan William J. SomersWilliam J. Somers More articles by this author , Diane felsenDiane felsen More articles by this author , Ting-Chao ChouTing-Chao Chou More articles by this author , Donald N. MarionDonald N. Marion More articles by this author , Chris E. CherneskyChris E. Chernesky More articles by this author , and E. Darracott VaughanE. Darracott Vaughan More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(17)41227-4AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail The role of alpha2 adrenergic receptors in the prostate in vivo is unknown. A model was developed to measure canine prostatic urethral pressure in vivo, and to assess the ability of various alpha adrenergic blocking agents to affect prostatic pressure. In this model, an esophogeal pressure catheter is inserted into the prostatic urethra to record prostatic urethral pressure. We investigated the effects of alpha adrenergic agonists and antagonists on prostatic pressure using this model. Dose-response curves were generated for epinephrine, and were then repeated in the presence of either prazosin (alpha1 antagonist), yohimbine (alpha2 antagonist) or SK&F-86466 (alpha2 antagonist). Prazosin was the most potent of the three drugs in competitively blocking epinephrine-induced contraction of the prostate, with an inhibition constant of 0.24µg./kg. calculated from the double reciprocal plot. Clonidine, an alpha2 adrenergic agonist, caused contraction of the prostate, which was also blocked by prazosin. Furthermore, the specific alpha2 agonist BHT-920 was totally inactive in our system. These results demonstrate that the increase in urethral pressure caused by alpha-adrenergic agonists can be blocked by alpha adrenergic antagonists. However, the specific alpha1 antagonist, prazosin, is more potent than alpha2 antagonists, and is also effective against an alpha2 agonist, clonidine. This suggests that blockade of alpha1 receptors may be a more useful strategy for causing relaxation of the prostate than blockade of alpha2 receptors. © 1989 by The American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsCited byImajo C, Walden P, Shapiro E, Doherty A and Lepor H (2018) Evaluation of the Effect of Endothelin-1 and Characterization of the Selective Endothelin A Receptor Antagonist PD155080 in the ProstateJournal of Urology, VOL. 158, NO. 1, (253-257), Online publication date: 1-Jul-1997.Tong-Long Lin A, Chen M, Chiang H, Yang C and Chang L (2018) Effect of Orchiectomy on the Alpha Adrenergic Contractile Response of Dog ProstateJournal of Urology, VOL. 154, NO. 5, (1930-1933), Online publication date: 1-Nov-1995.Breslin D, Fields D, Chou T, Marion D, Kane M, Vaughan E and Felsen D (2018) Medical Management of Benign Prostatic Hyperplasia: A Canine Model Comparing the in Vivo Efficacy of Alpha-1 Adrenergic Antagonists in the ProstateJournal of Urology, VOL. 149, NO. 2, (395-399), Online publication date: 1-Feb-1993. Volume 141Issue 5May 1989Page: 1230-1233 Advertisement Copyright & Permissions© 1989 by The American Urological Association Education and Research, Inc.MetricsAuthor Information William J. Somers More articles by this author Diane felsen More articles by this author Ting-Chao Chou More articles by this author Donald N. Marion More articles by this author Chris E. Chernesky More articles by this author E. Darracott Vaughan More articles by this author Expand All Advertisement PDF downloadLoading ...