Expressions and mechanical functions of α1-adrenoceptor subtypes in hamster ureter

Tomiyama, Yoshitaka; Kobayashi, Kumi; Tadachi, Mariko; Kobayashi, Shinya; Inada, Yoichi; Kobayashi, Mamoru; Yamazaki, Yoshinobu

doi:10.1016/j.ejphar.2007.06.056

Cited by 21 publications

(17 citation statements)

References 14 publications

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“…We recently reported that α1A-adrenoceptors mediate ureteral contractions in mice, hamsters, and dogs (Tomiyama et al, 2007;Kobayashi et al, 2009a;Kobayashi et al, 2009b). In the present study, we used pharmacological techniques to compare the efficacy of the selective α1A-adrenoceptor antagonist silodosin with those of three nonselective α1-adrenoceptor antagonists (namely, doxazosin, terazosin, and alfuzosin) against α-adrenoceptor agonist-induced contractions in both mouse and hamster ureters.…”

Section: Discussionmentioning

confidence: 96%

“…More recent studies have shown that other α1-adrenoceptor antagonists (terazosin and alfuzosin) could be used to augment spontaneous stone expulsion and to reduce the time to expulsion of ureteral stones (Pricop et al, 2004;Mohseni et al, 2006). Recently, Sasaki et al (2008) demonstrated that α1A-adrenoceptors mediate ureteral contractions in humans, and we showed that ureteral contraction was mediated mainly via the α1A-adrenoceptor in mice, hamsters, and dogs (Tomiyama et al, 2007;Kobayashi et al, 2009a;Kobayashi et al, 2009b). However, it is unclear which of the currently available α1-adrenoceptor antagonists is the most suitable for stone discharge.…”

Section: Introductionmentioning

confidence: 93%

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Effects of four different .ALPHA.1-adrenoceptor antagonists on .ALPHA.-adrenoceptor agonist-induced contractions in isolated mouse and hamster ureters

Kobayashi

Tomiyama

Maruyama

et al. 2009

J. Smooth Muscle Res.

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Purpose: To compare the efficacy of the selective α1A-adrenoceptor antagonist silodosin with those of doxazosin, terazosin, and alfuzosin against α-adrenoceptor agonist-induced contractions in mouse and hamster ureters. Methods: The four α1-adrenoceptor antagonists were evaluated against norepinephrine-induced phasic contractions in mouse isolated ureteral preparations and against phenylephrine-induced sustained contractions in hamster isolated ureteral preparations using a functional experimental technique. Results: In mouse ureters, silodosin (a selective α1A-adrenoceptor antagonist), doxazosin (a nonselective α1-adrenoceptor antagonist), terazosin (a nonselective α1-adrenoceptor antagonist), and alfuzosin (a nonselective α1-adrenoceptor antagonist) all shifted the norepinephrine concentration-response curve to the right. The rank order of potencies (pKB value) was silodosin (9.47 ± 0.16) > doxazosin (8.62 ± 0.15) > terazosin (8.39 ± 0.16) > alfuzosin (8.03 ± 0.12). In hamster ureters, all four antagonists shifted the phenylephrine concentration-response curve to the right, the rank order of potencies being silodosin (10.09 ± 0.13) > doxazosin (8.22 ± 0.16) > terazosin (7.75 ± 0.15) > alfuzosin (7.70 ± 0.10). In each case, silodosin was much more potent than the other three drugs. Conclusion: In this study, silodosin suppressed both mouse and hamster ureteral contractions more potently than doxazosin, terazosin, or alfuzosin. Hence, this α1A-adrenoceptor antagonist warrants further study as a potentially very useful medication for stone passage in urolithiasis patients.

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Section: Discussionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 93%

Effects of four different .ALPHA.1-adrenoceptor antagonists on .ALPHA.-adrenoceptor agonist-induced contractions in isolated mouse and hamster ureters

Kobayashi

Tomiyama

Maruyama

et al. 2009

J. Smooth Muscle Res.

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“…However, Tomiyama et al . reported that, in the hamster ureter, ureteral contraction was mediated mainly by α 1A ‐adrenoceptors, even though α 1D ‐adrenoceptors were more prevalent . Besides, Tsuzaka et al .…”

Section: Discussionmentioning

confidence: 99%

Efficacy and safety of silodosin in the medical expulsion therapy for distal ureteral calculi: a systematic review and meta‐analysis

Huang

Xue

Zong

et al. 2015

Brit J Clinical Pharma

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Aims Using a selective α‐adrenoceptor blocker for medical expulsive therapy (MET) is an effective treatment approach widely used for ureteral stones. The aim of the review was to assess the efficacy and safety of silodosin in medical expulstion therapy compared with placebo and tamsulosin. Methods A systematic search was performed in PubMed, Cochrane Library and Embase to identify randomized controlled trials that compared silodosin with a placebo or tamsulosin for ureteral calculi. Results Eight publications involving a total of 1048 patients were used in the analysis, which compared silodosin with placebo and tamsulosin. We found that silodosin was effective in treating ureteral calculi in our meta‐analysis and was superior to tamsulosin in its efficacy. The expulsion rate of all ureteral stones (OR 1.59, 95% CI 1.08, 2.36, P = 0.02), the expulsion rate of distal ureteral stones (OR 2.82, 95% CI 1.70, 4.67, P < 0.0001) and the expulsion time (days) of distal ureteral stones (standard mean difference (SMD) −4.71, 95% CI −6.60, −2.83, P < 0.00001) indicated that silodosin was more effective than the placebo. Moreover, expulsion rate (OR 2.54, 95% CI 1.70, 3.78, P < 0.00001), expulsion time (days) (SMD −2.64, 95% CI −3.64, −1.64, P < 0.00001) and pain episodes (P < 0.00001) indicated that silodosin was more effective than the tamsulosin. Even though silodosin had a significant increase in abnormal ejaculation compared with tamsulosin, no significant differences were observed for complications (OR 1.00, 95% CI 0.58, 1.74, P = 1.00). Conclusions This meta‐analysis indicated that silodosin was superior to placebo or tamsulosin in the efficacy for distal ureteral calculi with better control of pain. The safety profile of silodosin was similar to tamsulosin though retrograde ejaculation was worse for silodosin use. We conclude that silodosin might have potential as a MET for ureteral stones.

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Section: Discussionmentioning

confidence: 99%

Naftopidil vs silodosin in medical expulsive therapy for ureteral stones: A randomized controlled study in Japanese male patients

et al. 2011

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Abstract:The aim of the present study was to compare the efficacy of the selective a1D-adrenoceptor antagonist naftopidil and the selective a1A-adrenoceptor antagonist silodosin (as an example) in the management of ureteral stones in Japanese male patients. A total of 74 patients with symptomatic Յ10 mm ureteral stones were enrolled in a prospective study and randomized into two groups: Group 1 received 50 mg naftopidil daily, whereas Group 2 received 8 mg silodosin daily. Patients were followed-up for up to 6 weeks. The primary endpoint was stone expulsion rate and secondary endpoints were stone expulsion time, the rate of interventions, such as transurethral ureterolithotripsy, extracorporeal shock wave lithotripsy, or ureteral stenting, and side effects. There were no significant differences between the two groups with respect to age, stone size, and location. The stone expulsion rate was 61% and 84% in the naftopidil and silodosin groups, respectively (P = 0.038). No significant differences were noted in stone expulsion time or the rate of interventions between the two groups. The findings suggest that a1A-adrenoceptor blockade was clinically superior for stone expulsion our study population.

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Expressions and mechanical functions of α1-adrenoceptor subtypes in hamster ureter

Cited by 21 publications

References 14 publications

Effects of four different .ALPHA.1-adrenoceptor antagonists on .ALPHA.-adrenoceptor agonist-induced contractions in isolated mouse and hamster ureters

Effects of four different .ALPHA.1-adrenoceptor antagonists on .ALPHA.-adrenoceptor agonist-induced contractions in isolated mouse and hamster ureters

Efficacy and safety of silodosin in the medical expulsion therapy for distal ureteral calculi: a systematic review and meta‐analysis

Naftopidil vs silodosin in medical expulsive therapy for ureteral stones: A randomized controlled study in Japanese male patients

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