Background: α–Agonists and endothelins (ETs) are the only agents that have been proved to induce significant contraction of the prostate. Although the response to phenylephrine (PE) is dependent on the quality of smooth muscle (SM) within the prostate, it is not clear whether the response to ET–1 is also influenced by SM density. We evaluate the relationship between contractile responsiveness to ET–1 and the area density of SM of the human prostate.Materials and Methods: Specimens were obtained from 17 patients with prostatic hyperplasia that underwent transurethral resection of the prostate. Specimens were used for isometric tension study (PE, KCl and ET) and also for quantitative morphometric analysis.Results: PE and ET–1 induced dose–dependent contractile responses. There were no significant differences in the average maximum response (Emax) to these two agents. Emax to KCl and PE showed direct positive correlations with the area density of SM. Emax to ET–1 also showed a positive correlation with the SM density, although this relationship was weaker than those for the other two agents. Moreover, there was a strong positive relationship between Emax to PE, KCl and that to ET–1.Conclusions: The area density of SM appeared to significantly influence the contractile response to ET–1 as well as the response to PE and KCl.

1.
Lepor H: Medical therapy for benign prostatic hyperplasia. Urology 1993;42:483–501.
2.
Caine M, Perlberg S: Dynamics of acute retention in prostatic patient and role of adrenoceptors. Urology 1977;9:399–403.
3.
Furuya SY, Kumamoto E, Yokoyama T, Tsukamoto T, Izumi T, Abiko Y: Alpha–adrenergic activity and urethral pressure in prostatic zone in benign prostatic hypertrophy. J Urol 1982;128:836–839.
4.
Hedlund H, Andersson K–E, Ek A: Effects of prazosin on patients with benign prostatic obstruction. J Urol 1983;130:275–278.
5.
Kirby RS, Coppinger SWC, Corcoran MO, Chapple CR, Flannigan M, Milroy EJG: Prazosin in the treatment of prostatic obstruction: A placebo–controlled study. Br J Urol 1987;60: 136–142.
6.
Lepor H, Auerbach S, Puras–Baez A, Narayan P, Soloway M, Lowe F, Moon T, Leifer G, Madsen P: A randomized, placebo–controlled multicenter study of the efficacy and safety of terazosin in the treatment of benign prostatic hyperplasia. J Urol 1992;148:1467–1474.
7.
Hedlung H, Andersson K–E, Larson BL Alpha–adrenoceptors and muscarinic receptors in the isolated human prostate. J Urol 1985;134: 1291–1298.
8.
Hieble JP, Boyce AJ, Caine M: Comparison of the alpha–adrenoceptor characteristics in human and canine prostate. Fed Proc 1986;45: 2609–2614.
9.
Gup DI, Shapiro E, Baumann M, Lepor H: Contractile properties of human prostate adenomas and development of infravesical obstruction. Prostate 1989;15:105–114.
10.
Gup DI, Shapiro E, Baumann M, Lepor H: Autonomic receptors in human benign prostatic hyperplasia. J Urol 1990;143:179–185.
11.
Lepor H, Gup DI, Baumann M, Shapiro E: Comparison of alpha–1 adrenoceptors in the prostate capsule of men with symptomatic and asymptomatic human prostatic hyperplasia. Br J Urol 1991;67:493–498.
12.
Lepor H, Kobayashi S, Shapiro E, Forray C, Wetzel JM, Gluchowski C: Localization of the α1a–adrenoceptor in the human prostate. J Urol 1995;154:2096–2099.
13.
Langestroer P, Tang R, Shapiro E, Divish B, Opgenorth T, Lepor H: Endothelin–1 in the human prostate: Tissue levels, source of production and isometric tension studies. J Urol 1993; 149:495–499.
14.
Gup DI, Shapiro E, Baumann M, Lepor H: Contractile properties of human prostate adenomas and development of infravesical obstruction. Prostate 1998;15:105–114.
15.
Kondo S, Morita T, Tashima Y: Benign prostatic hypertrophy affects the endothelin receptor density in the human urinary bladder and prostate. Urol Int 1996;54:198–203.
16.
Ishigooka M, Hashimoto T, Suzuki Y, Ichiyanagi O, Sasagawa I, Aoyama N, Nakada T: Functional property, norepinephrine content and morphometric findings in human hyperplastic prostate. Prostate 1997;33:183–187.
17.
Shapiro E, Haratanto V, Lepor H: The response to alpha blockade in benign prostatic hyperplasia is related to the percent area density of prostate smooth muscle. Prostate 1992; 21:297–307.
18.
Barry MJ, Fowler FJ, O’Leary MP, Bruskewitz RC, Holtgrewe HL, Mebust WK, Cockett ATK, the measurement committee of the American Urological Association: The American Urological Association symptom index for benign prostatic hyperplasia. J Urol 1992;148: 1549–1557.
19.
Roehrborn CG, Chinn HKW, Fulgham PF, Simpkins KL, Peters CP: The role of transabdominal ultrasound in the preoperative evaluation of patients with benign prostatic hypertrophy. J Urol 1986;135:1190–1193.
20.
Abrams P, Blaivas JG, Stanton SL, Andersen JT: The standardization of terminology of lower urinary tract function recommended by the international continence society. Int Urogynecol J 1990;1:45–58.
21.
Schäfer W: Principles and clinical application of advanced urodynamic analysis of voiding function. Urol Clin North Am 1990;17:553– 566.
22.
Siegel YI, Zaidel L, Hammel I, Korczak D, Linder A: Morphometric evaluation of benign prostate hyperplasia. Eur Urol 1990;18:71–73.
23.
Bartsch G, Keen F, Daxenbichler G, Marth Ch, Margreiter R, Brungger A, Sutter T, Rohr HP: Correlation of biochemical (receptors, endogenous tissue hormones) and quantitative morphologic (stereologic) findings in normal and hyperplastic human prostate. J Urol 1987;137: 559–564.
24.
Ishigooka M, Hashimoto T, Hayamai S, Suzuki Y, Sasagawa I, Nakada T: Correlation between morphometric differences and norepinephrine content in bening prostatic hyperplasia. Prostate 1996;28:385–391.
25.
Kobayashi S, Tang R, Wang B, Opgenorth T, Langenstroer P, Shapiro E, Lepor H: Binding and functional properties of endothelin receptor subtypes in the human prostate. Mol Pharmacol 1994;151:763–766.
26.
Moriyama N, Kurimoto S, Miyata N, Yamaura H, Yamazaki R, Sudoh K, Inagaki O, Takenaka T, Kawabe K: Decreased contractile effect of endothelin–1 on hyperplastic prostate. Gen Pharmacol 1996;27:1061–1065.
27.
Robert M, Costa P, Bressolle F, Mottet N, Navratil H: Percent area density of epithelial and mesenchymal components in benign prostatic hyperplasia: Comparison of results between single biopsy, multiple biopsies and multiple tissue specimens. Br J Urol 1995;75: 317–324.
28.
Kurita Y, Masuda H, Suzuki K, Fujita K, Kawabe K: Transition zone ratio and prostate–specific antigen density as predictors of the response of benign prostatic hypertrophy to alpha blocker and anti–androgen therapy. Br J Urol 1997;80:78–83.
29.
Weijers RE, Zambon J–V, Kessels AGH, de Bruyne AP: On the prediction of the histologic composition of benign prostatic hyperplasia based on clinical and MRI parameters. Prostate 1997;32:179–187.
30.
Imajo C, Walden PD, Shapiro E, Doherty AM, Lepor H: Evaluation of the effect of endothelin–1 and characterization of the selective endothelin A receptor antagonist PD155080 in the prostate. J Urol 1997;158:253–257.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.