The Role of M2 Muscarinic Receptor Subtypes Mediating Contraction of the Circular and Longitudinal Smooth Muscle of the Pig Proximal Urethra
2002; Lippincott Williams & Wilkins; Volume: 168; Issue: 1 Linguagem: Inglês
10.1016/s0022-5347(05)64913-0
ISSN1527-3792
AutoresTomonori Yamanishi, Christopher R. Chapple, Kosaku Yasuda, Ken-ichiro Yoshida, Russ Chess‐Williams,
Tópico(s)Receptor Mechanisms and Signaling
ResumoNo AccessJournal of UrologyINVESTIGATIVE UROLOGY1 Jul 2002The Role of M2 Muscarinic Receptor Subtypes Mediating Contraction of the Circular and Longitudinal Smooth Muscle of the Pig Proximal Urethra Tomonori Yamanishi, Christopher R. Chapple, Kosaku Yasuda, Ken-Ichiro Yoshida, and Russell Chess-Williams Tomonori YamanishiTomonori Yamanishi , Christopher R. ChappleChristopher R. Chapple , Kosaku YasudaKosaku Yasuda , Ken-Ichiro YoshidaKen-Ichiro Yoshida , and Russell Chess-WilliamsRussell Chess-Williams View All Author Informationhttps://doi.org/10.1016/S0022-5347(05)64913-0AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract Purpose: We investigated the characterization of muscarinic receptor subtypes in the female pig urethra. Materials and Methods: The affinities of muscarinic antagonists against carbachol responses were calculated in normal and cyclic adenosine monophosphate (cAMP) elevated tissues (contraction with KCl and relaxation with isoprenaline) using longitudinal and transverse strips of urethra. Results: In displacement experiments with 1-quinuclidinyl [phenyl-4-3H] benzilate inhibitory constant (pKi) values of 4-diphenylacetoxyl-N-methyl-piperidine methiodide (DAMP) M3 selective antagonist) and methoctramine (M2 antagonist) indicated the presence of the M2 receptor. In functional studies contraction responses to carbachol were greater in longitudinal than in circular muscle. After cAMP elevation the contraction response increased in circular muscles to the level close to that of longitudinal muscles but did not change significantly in cAMP elevated longitudinal muscle. On normal circular tissues 4-DAMP had high mean affinity (mean apparent pKB value 9.3) but with a Schild slope of less than unity (0.76). Methoctramine competitively antagonized carbachol responses (mean affinity [pA2] value 6.9). On normal longitudinal tissues 4-DAMP and methoctramine competitively antagonized carbachol responses (mean pA2 9.0 and 6.2, respectively). After cAMP elevation in circular tissues mean pA2 values for 4-DAMP (8.7) were significantly lower (p = 0.0015), and those for methoctramine (7.3) were significantly higher (p = 0.0193) than in normal tissues. In longitudinal tissues the mean pA2 value for methoctramine (6.9) was significantly greater than in normal tissues (p <0.0001) but the value for 4-DAMP (8.8) did not alter. Conclusions: Pig urethra appears to have predominantly M2 muscarinic receptors. Contraction of the normal urethra appears to be predominantly mediated by M2 and M3 receptors in circular muscle but by M3 receptors in longitudinal muscle. 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Link, Google Scholar From the Department of Biomedical Science, University of Sheffield and Department of Urology, Royal Hallamshire Hospital, Sheffield, United Kingdom, and Department of Urology, Dokkyo University, Tochigi, Japan© 2002 by American Urological Association, Inc.FiguresReferencesRelatedDetailsCited ByYokoyama O, Miwa Y, Oyama N, Aoki Y, Ito H and Akino H (2018) Antimuscarinic Drug Inhibits Detrusor Overactivity Induced by Topical Application of Prostaglandin E2 to the Urethra With a Decrease in Urethral PressureJournal of Urology, VOL. 178, NO. 5, (2208-2212), Online publication date: 1-Nov-2007.YAMANISHI T, CHAPPLE C, YASUDA K, YOSHIDA K and CHESS-WILLIAMS R (2018) The Functional Role of β-Adrenoceptor Subtypes in Mediating Relaxation of Pig Urethral Smooth MuscleJournal of Urology, VOL. 170, NO. 6, (2508-2511), Online publication date: 1-Dec-2003. Volume 168Issue 1July 2002Page: 308-314 Advertisement Copyright & Permissions© 2002 by American Urological Association, Inc.Keywordsreceptors, muscarinicurethraswinecarbacholmuscle, smoothMetricsAuthor Information Tomonori Yamanishi More articles by this author Christopher R. Chapple More articles by this author Kosaku Yasuda More articles by this author Ken-Ichiro Yoshida More articles by this author Russell Chess-Williams More articles by this author Expand All Advertisement PDF DownloadLoading ...
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