Preclinical Pharmacology of &amp;alpha;&lt;sub&gt;1&lt;/sub&gt;-Adrenoceptor Antagonists

Martin, Denis

doi:10.1159/000052316

Cited by 30 publications

(20 citation statements)

References 15 publications

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“…Moreover, Akiyama et al (1999) demonstrated in anesthetized rats that silodosin suppressed an α1A-adrenoceptor-mediated response (the increase in intraurethral pressure induced by phenylephrine) without seriously altering mean blood pressure, with selectivity (α1A-adrenoceptor-mediated response against hypotensive effect) being markedly greater for silodosin (29.7) than for terazosin (0.52). In the present study, the effect of terazosin in the two ureters was quite similar to those of doxazosin and alfuzosin, and reportedly there is close similarity among these three drugs in that each of them displays almost completely nonselective antagonistic activities against the three subtypes of α1-adrenoceptor (α1A, α1B, and α1D) (Martin, 1999). Accordingly, doxazosin and alfuzosin, like terazosin, would not be expected to be selective for the ureters versus the cardiovascular system.…”

Section: Discussionsupporting

confidence: 58%

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: Discussionsupporting

confidence: 58%

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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“…6 A survey of thyroid function in patients with PBC revealed the presence of thyroid antibodies in 26% of patients. 7 A nationwide survey in Japan found autoimmune thyroiditis to be associated with primary biliary cirrhosis in 5.8% of cases. 8 Gordon and Isenberg suggest that there is an overlap between polmyalgia rheumatica (PMR) and GCA with autoimmune thyroid dysfunction.…”

Section: Commentmentioning

confidence: 99%

“…[5][6][7] We postulate that the overall in vivo affinity of the a1-adrenergic receptor blockers towards a1A-subtype receptors might be responsible for IFIS rather than the in vitro a1A-selectivity per se. 2,7 We agree with previous authors that preoperative recognition of patients at risk of IFIS allows for appropriate surgical planning in anticipation of IFIS, with the intention of reducing the risk of preoperative complications. 1 It is our practice to insert, at commencement of surgery, disposable flexible translimbal iris retractors in a diamond configuration, as described by Oetting and Omphroy.…”

mentioning

confidence: 99%

Ocular trauma caused by a loose slip-lock cannula during corneal hydration

Bradshaw

Shankar

Maini

et al. 2006

Eye

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the a1A-adrenergic receptors on the iris dilator muscle, resulting in disuse atrophy of the muscle; this in turn affects iris rigidity. 1 Controversy exists over the receptor subtypes present in the prostate and the precise mechanism of action of this type of agents. [2][3][4] Recent experience in our unit is in accord with Chang's report; 1 the majority of patients treated with tamsulosin undergoing cataract surgery seem to display the features of IFIS. We have noted no benefit from the temporary cessation of treatment preoperatively.The case we present here was, we believe, typical of IFIS. We are not aware of any previous reports of IFIS in patients treated with a1-adrenergic receptor blockers other than tamsulosin. It has been suggested that the a1A-subtype selectivity of tamsulosin might be accountable for the clinical manifestation of IFIS. 1 Alfuzosin, although not a1A-subtype-selective in vitro, 2,3,5-9 displays uroselective properties in vivo. [5][6][7] We postulate that the overall in vivo affinity of the a1-adrenergic receptor blockers towards a1A-subtype receptors might be responsible for IFIS rather than the in vitro a1A-selectivity per se. 2,7 We agree with previous authors that preoperative recognition of patients at risk of IFIS allows for appropriate surgical planning in anticipation of IFIS, with the intention of reducing the risk of preoperative complications. 1 It is our practice to insert, at commencement of surgery, disposable flexible translimbal iris retractors in a diamond configuration, as described by Oetting and Omphroy. 10 This seems to allow the operation to be completed safely and with little added difficulty.We believe that surgeons should anticipate IFIS in patients taking alfuzosin, in addition to those taking tamsulosin, and quite possibly in patients taking any of the uroselective a1-adrenergic receptor blockers. We are not aware of any reports of the nonuroselective a1-adrenergic receptor blockers causing IFIS. Comparison of tamsulosin with alfuzosin in the treatment of patients with lower urinary tract symptoms suggestive of bladder outlet obstruction (symptomatic benign prostatic hyperplasia). The European Tamsulosin Study Group. Br J Urol 1997; 80(4): 597-605. 9 Martin DJ, Lluel P, Guillot E, Coste A, Jammes D, Angel I.Comparative alpha-1 adrenoceptor subtype selectivity and functional uroselectivity of alpha-1 adrenoceptor antagonists.

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“…However, alfuzosin is thought to not enter the CNS and yet is effective in BPH. 95 A comparison of ef®cacy for relief of storage symptoms (irritative, LUTS) based on CNS penetration would be of interest in this regard. Ef®cacy has usually been determined from a composite scoring of symptom relief.…”

Section: Roehrbornmentioning

confidence: 99%

α1-Adrenoceptor selectivity and the treatment of benign prostatic hyperplasia and lower urinary tract symptoms

Kirby

Lepor

et al. 2000

Prostate Cancer Prostatic Dis

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The storage (irritative) and voiding (obstructive) symptoms associated with benign prostatic hyperplasia are generally attributed to prostate enlargement and increased prostatic smooth muscle tone mediated by the prevailing a 1 -adrenoceptors in the bladder neck and prostate. This results in obstruction and subsequent secondary changes to the bladder. However, there is growing evidence that many of these symptoms may be due to changes in extraprostatic a 1 -adrenoceptors, possibly a 1D -adrenoceptors. Findings from the VA cooperative trial challenge the current theory that the common side effects associated with these agents are due to vascular action of a 1 -adrenoceptor blockers. Prostate Cancer and Prostatic Diseases (2000) 3, 76±83.

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Preclinical Pharmacology of α<sub>1</sub>-Adrenoceptor Antagonists

Cited by 30 publications

References 15 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

Ocular trauma caused by a loose slip-lock cannula during corneal hydration

α1-Adrenoceptor selectivity and the treatment of benign prostatic hyperplasia and lower urinary tract symptoms

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