Responsiveness of smooth muscle in the lower urinary tract of rabbits to various agonists

Sudoh, Katsumi; Inagaki, Osamu; Honda, Kazuo

doi:10.1016/s0306-3623(96)00292-3

Cited by 11 publications

(4 citation statements)

References 6 publications

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“…Preliminary evidence as seen in this study shows that prostaglandin E 2 is able to inhibit electrically stimulated contractile responses in a concentration‐dependent manner similar in magnitude to WIN 55,212‐2. It has been shown that in the prostate molecular products of the COX pathway cause a contractile response, which contradicts what was observed in this study ( Kitada and Kumazawa, 1987 ; Sudoh et al ., 1997 ). However, in those studies prostaglandins were tested in the absence of any electrical field stimulation and this could account for the difference seen in the results.…”

Section: Discussioncontrasting

confidence: 99%

Stimulation of epithelial CB₁ receptors inhibits contractions of the rat prostate gland

Tokanovic

Malone

Ventura

2007

British J Pharmacology

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Background and purpose: This study investigated whether stimulation of cannabinoid receptors influences smooth muscle contractility in the rat prostate gland. Experimental approach: Immunohistochemistry was used to characterize and localize cannabinoid receptors in the rat prostate gland. Isolated organ bath experiments were carried out to investigate the effects of cannabinoids on prostate contractility. Key results: Immunohistochemical studies of the rat prostate yielded positive immunoreactivity for the CB 1 receptor, but not the CB 2 receptor. Double labelling revealed that CB 1 receptors were not colocalized with a-actin in the smooth muscle layer but were primarily expressed within the epithelial lining of the prostatic acini. The cannabinoid receptor agonist WIN 55,212-2 (10 nM -10 mM) inhibited contractile responses to electrical-field stimulation (10 Hz, 0.5 ms, 60 V for 2 s per minute) in a concentration-dependent manner. The CB 1 selective antagonists, SR141716 (1 mM) and LY 320135 (1 mM), reversed the WIN 55,212-2-mediated inhibition but the CB 2 selective antagonist, SR144528 (1 mM), did not. Furthermore, the cyclooxygenase inhibitor indomethacin (0.1 mM) caused significant reversal of the WIN 55,212-2 mediated inhibition of contractile responses, whereas the nitric oxide synthase inhibitor N o -nitro-L-arginine methyl ester hydrochloride (L-NAME, 1 mM) did not. Prostaglandin E 2 (10 nM -10 mM), produced a similar concentration-dependent inhibition to WIN 55,212-2. Conclusions and implications: WIN 55,212-2, an agonist at cannabinoid receptors, causes inhibition of smooth muscle contraction in the rat prostate by activating epithelial CB 1 receptors. This inhibition is mediated via the cyclooxygenase pathway.

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Section: Discussioncontrasting

confidence: 99%

Stimulation of epithelial CB₁ receptors inhibits contractions of the rat prostate gland

Tokanovic

Malone

Ventura

2007

British J Pharmacology

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“…Thus, reactions to serotonin were lacking or below 10% of noradrenaline in rat and dog prostates, while prostates from guineapigs reacted with contractions of more than 70% of KCl to serotonin [51,52]. Reactions to histamine were lacking or ranging between 10 and 20% of noradrenaline in rat and rabbit prostates, ranging around 50% of noradrenaline in the dog prostate, or ranging between 75 and 105% of KCl in guinea-pig prostates [51,[53][54][55]. Together and contrary to previous statements, we suggest that serotonin and histamine should be deleted from the list of relevant contractile mediators in the human prostate.…”

Section: Discussionmentioning

confidence: 99%

Non‐Adrenergic, Tamsulosin‐Insensitive Smooth Muscle Contraction is Sufficient to Replace α₁‐Adrenergic Tension in the Human Prostate

et al. 2017

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Contractions following concomitant confrontation of human prostate tissue with noradrenaline and endothelin-1 are not additive. Endothelin-1 is sufficient to induce a smooth muscle tone resembling that of noradrenaline. This may replace lacking α -adrenergic tone under therapy with α -blockers, explaining the limited efficacy of α -blockers in LUTS treatment. Contractions by thromboxane and endothelin-1 may be additive, and may exceed α -adrenergic tone. Prostate 77:697-707, 2017. © 2017 Wiley Periodicals, Inc.

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“…Quinacrine, indomethacin, and AA861 significantly inhibited the contraction, suggesting that cyclooxygenase metabolites and 5-lipoxygenase metabolites are involved in the response. In fact, prostaglandins have been reported to be a constricting agent in the rabbit urethra (24), but the involvement of 5-lipoxygenase metabolites have not been reported. In the present study, the contraction resistant to prazosin was inhibited by ZK 158252, a leukotriene (LT) B 4 -receptor antagonist (18), but was not by montelukast, a CysLt 1 -receptor antagonist, suggesting that LTB 4 , but not LTC 4 or LTD 4 , is involved in the response.…”

Section: Discussionmentioning

confidence: 98%

Mechanisms Underlying Mechanical Responses to Ephedra herb of Isolated Rabbit Urinary Bladder and Urethra, a Possible Stress Urinary Incontinence Therapeutic

Ayajiki¹,

Kimura²,

Yamamizu³

et al. 2008

J Pharmacol Sci

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Abstract. To compare the mechanisms underlying mechanical responses to ephedrine and Ephedra herb, a main component of Kakkon-to, in isolated male and female rabbit urinary bladder and urethral strips, responses of isolated strips to the agents were recorded in organ bath systems. Ephedrine and Ephedra herb relaxed the female urinary bladder to the similar extent. These relaxations are reversed to contractions by timolol. In the presence of timolol, ephedrine produced less contraction of urethral strips in the female than those in the male; this contraction was abolished by prazosin. Ephedra herb contracted the female urethra less than that of the male, and the contraction was stronger than that by ephedrine. The contraction caused by Ephedra herb in strips treated with timolol was significantly inhibited by prazosin. The prazosin-resistant contraction of the female urethra was greater than that of the male. Quinacrine, a phospholipase A 2 inhibitor, indomethacin, and AA861, a 5-lipoxygenase inhibitor, inhibited the contraction. The contraction was inhibited by ZK 158252, a leukotriene (LT) B 4 -receptor antagonist. These findings suggest that Ephedra herb contracts the urethra via arachidonic acid metabolites together with α 1 -adrenoceptor stimulation. The metabolites produced by 5-lipoxygenase may stimulate LTB 4 , but not CysLt 1 , receptors. These contractile components induced by Ephedra herb and Kakkon-to might be effective for the treatment of stress urinary incontinence.

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Responsiveness of smooth muscle in the lower urinary tract of rabbits to various agonists

Cited by 11 publications

References 6 publications

Stimulation of epithelial CB₁ receptors inhibits contractions of the rat prostate gland

Stimulation of epithelial CB₁ receptors inhibits contractions of the rat prostate gland

Non‐Adrenergic, Tamsulosin‐Insensitive Smooth Muscle Contraction is Sufficient to Replace α₁‐Adrenergic Tension in the Human Prostate

Mechanisms Underlying Mechanical Responses to Ephedra herb of Isolated Rabbit Urinary Bladder and Urethra, a Possible Stress Urinary Incontinence Therapeutic

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Responsiveness of smooth muscle in the lower urinary tract of rabbits to various agonists

Cited by 11 publications

References 6 publications

Stimulation of epithelial CB1 receptors inhibits contractions of the rat prostate gland

Stimulation of epithelial CB1 receptors inhibits contractions of the rat prostate gland

Non‐Adrenergic, Tamsulosin‐Insensitive Smooth Muscle Contraction is Sufficient to Replace α1‐Adrenergic Tension in the Human Prostate

Mechanisms Underlying Mechanical Responses to Ephedra herb of Isolated Rabbit Urinary Bladder and Urethra, a Possible Stress Urinary Incontinence Therapeutic

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Stimulation of epithelial CB₁ receptors inhibits contractions of the rat prostate gland

Stimulation of epithelial CB₁ receptors inhibits contractions of the rat prostate gland

Non‐Adrenergic, Tamsulosin‐Insensitive Smooth Muscle Contraction is Sufficient to Replace α₁‐Adrenergic Tension in the Human Prostate