The role of the urothelium in mediating bladder responses to isoprenaline

Shigetaka Murakami, Christopher R. Chapple, Hironobu Akino, Donna J. Sellers, Russell Chess-Williams

Research output: Contribution to journalArticleResearchpeer-review

51 Citations (Scopus)

Abstract

OBJECTIVES: To investigate whether the responses of the pig bladder to isoprenaline (a nonselective β-adrenoceptor agonist) are influenced by the presence of an intact urothelium and whether any influence might be attributed to the release of nitric oxide (NO), since stimulation of β-adrenoceptors induces a direct relaxation of detrusor smooth muscle and β-adrenoceptors are also present on the urothelium. MATERIAL AND METHODS: Paired (in the presence or absence of urothelium) longitudinal strips of pig bladder dome were set up in tissue baths and the developed tension recorded. Relaxation responses to isoprenaline were examined after pre-contraction with carbachol. The inhibitory effects of isoprenaline were examined by comparing responses to carbachol in the absence and presence of isoprenaline. To examine a possible role for NO, similar experiments were performed in the presence of the NO synthase inhibitor NG-nitro-l-arginine (L-NNA). RESULTS: In the presence of the urothelium, both the potency (pEC50) and the maximum contractile responses to carbachol were depressed. In relaxation experiments, isoprenaline relaxed carbachol pre-contracted tissues by ≈75%, and the potency and maximum relaxation were similar in the absence and presence of the urothelium. In the inhibition experiments, the presence of isoprenaline caused rightward parallel shifts of the concentration-response curves to carbachol, but isoprenaline did not influence the maximum contractions. In the presence of the urothelium there was a greater shift with 0.1 μm isoprenaline than in denuded tissues. Incubation with L-NNA did not affect the influence of the urothelium on responses to isoprenaline in any experimental group. CONCLUSIONS: The relaxation responses of the bladder to isoprenaline do not appear to involve the urothelium or NO release in vitro. However, contractile responses to carbachol were inhibited in the presence of an intact urothelium, and this might reflect the release of an inhibitory factor other than NO.

Original languageEnglish
Pages (from-to)669-673
Number of pages5
JournalBJU International
Volume99
Issue number3
DOIs
Publication statusPublished - Mar 2007

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Urothelium
Isoproterenol
Urinary Bladder
Carbachol
Nitric Oxide
Adrenergic Receptors
Swine
Nitroarginine
Baths
Nitric Oxide Synthase
Smooth Muscle

Cite this

Murakami, Shigetaka ; Chapple, Christopher R. ; Akino, Hironobu ; Sellers, Donna J. ; Chess-Williams, Russell. / The role of the urothelium in mediating bladder responses to isoprenaline. In: BJU International. 2007 ; Vol. 99, No. 3. pp. 669-673.
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title = "The role of the urothelium in mediating bladder responses to isoprenaline",
abstract = "OBJECTIVES: To investigate whether the responses of the pig bladder to isoprenaline (a nonselective β-adrenoceptor agonist) are influenced by the presence of an intact urothelium and whether any influence might be attributed to the release of nitric oxide (NO), since stimulation of β-adrenoceptors induces a direct relaxation of detrusor smooth muscle and β-adrenoceptors are also present on the urothelium. MATERIAL AND METHODS: Paired (in the presence or absence of urothelium) longitudinal strips of pig bladder dome were set up in tissue baths and the developed tension recorded. Relaxation responses to isoprenaline were examined after pre-contraction with carbachol. The inhibitory effects of isoprenaline were examined by comparing responses to carbachol in the absence and presence of isoprenaline. To examine a possible role for NO, similar experiments were performed in the presence of the NO synthase inhibitor NG-nitro-l-arginine (L-NNA). RESULTS: In the presence of the urothelium, both the potency (pEC50) and the maximum contractile responses to carbachol were depressed. In relaxation experiments, isoprenaline relaxed carbachol pre-contracted tissues by ≈75{\%}, and the potency and maximum relaxation were similar in the absence and presence of the urothelium. In the inhibition experiments, the presence of isoprenaline caused rightward parallel shifts of the concentration-response curves to carbachol, but isoprenaline did not influence the maximum contractions. In the presence of the urothelium there was a greater shift with 0.1 μm isoprenaline than in denuded tissues. Incubation with L-NNA did not affect the influence of the urothelium on responses to isoprenaline in any experimental group. CONCLUSIONS: The relaxation responses of the bladder to isoprenaline do not appear to involve the urothelium or NO release in vitro. However, contractile responses to carbachol were inhibited in the presence of an intact urothelium, and this might reflect the release of an inhibitory factor other than NO.",
author = "Shigetaka Murakami and Chapple, {Christopher R.} and Hironobu Akino and Sellers, {Donna J.} and Russell Chess-Williams",
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The role of the urothelium in mediating bladder responses to isoprenaline. / Murakami, Shigetaka; Chapple, Christopher R.; Akino, Hironobu; Sellers, Donna J.; Chess-Williams, Russell.

In: BJU International, Vol. 99, No. 3, 03.2007, p. 669-673.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - The role of the urothelium in mediating bladder responses to isoprenaline

AU - Murakami, Shigetaka

AU - Chapple, Christopher R.

AU - Akino, Hironobu

AU - Sellers, Donna J.

AU - Chess-Williams, Russell

PY - 2007/3

Y1 - 2007/3

N2 - OBJECTIVES: To investigate whether the responses of the pig bladder to isoprenaline (a nonselective β-adrenoceptor agonist) are influenced by the presence of an intact urothelium and whether any influence might be attributed to the release of nitric oxide (NO), since stimulation of β-adrenoceptors induces a direct relaxation of detrusor smooth muscle and β-adrenoceptors are also present on the urothelium. MATERIAL AND METHODS: Paired (in the presence or absence of urothelium) longitudinal strips of pig bladder dome were set up in tissue baths and the developed tension recorded. Relaxation responses to isoprenaline were examined after pre-contraction with carbachol. The inhibitory effects of isoprenaline were examined by comparing responses to carbachol in the absence and presence of isoprenaline. To examine a possible role for NO, similar experiments were performed in the presence of the NO synthase inhibitor NG-nitro-l-arginine (L-NNA). RESULTS: In the presence of the urothelium, both the potency (pEC50) and the maximum contractile responses to carbachol were depressed. In relaxation experiments, isoprenaline relaxed carbachol pre-contracted tissues by ≈75%, and the potency and maximum relaxation were similar in the absence and presence of the urothelium. In the inhibition experiments, the presence of isoprenaline caused rightward parallel shifts of the concentration-response curves to carbachol, but isoprenaline did not influence the maximum contractions. In the presence of the urothelium there was a greater shift with 0.1 μm isoprenaline than in denuded tissues. Incubation with L-NNA did not affect the influence of the urothelium on responses to isoprenaline in any experimental group. CONCLUSIONS: The relaxation responses of the bladder to isoprenaline do not appear to involve the urothelium or NO release in vitro. However, contractile responses to carbachol were inhibited in the presence of an intact urothelium, and this might reflect the release of an inhibitory factor other than NO.

AB - OBJECTIVES: To investigate whether the responses of the pig bladder to isoprenaline (a nonselective β-adrenoceptor agonist) are influenced by the presence of an intact urothelium and whether any influence might be attributed to the release of nitric oxide (NO), since stimulation of β-adrenoceptors induces a direct relaxation of detrusor smooth muscle and β-adrenoceptors are also present on the urothelium. MATERIAL AND METHODS: Paired (in the presence or absence of urothelium) longitudinal strips of pig bladder dome were set up in tissue baths and the developed tension recorded. Relaxation responses to isoprenaline were examined after pre-contraction with carbachol. The inhibitory effects of isoprenaline were examined by comparing responses to carbachol in the absence and presence of isoprenaline. To examine a possible role for NO, similar experiments were performed in the presence of the NO synthase inhibitor NG-nitro-l-arginine (L-NNA). RESULTS: In the presence of the urothelium, both the potency (pEC50) and the maximum contractile responses to carbachol were depressed. In relaxation experiments, isoprenaline relaxed carbachol pre-contracted tissues by ≈75%, and the potency and maximum relaxation were similar in the absence and presence of the urothelium. In the inhibition experiments, the presence of isoprenaline caused rightward parallel shifts of the concentration-response curves to carbachol, but isoprenaline did not influence the maximum contractions. In the presence of the urothelium there was a greater shift with 0.1 μm isoprenaline than in denuded tissues. Incubation with L-NNA did not affect the influence of the urothelium on responses to isoprenaline in any experimental group. CONCLUSIONS: The relaxation responses of the bladder to isoprenaline do not appear to involve the urothelium or NO release in vitro. However, contractile responses to carbachol were inhibited in the presence of an intact urothelium, and this might reflect the release of an inhibitory factor other than NO.

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