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Fürer K, Eberli D, Betschart C, Brenneisen R, De Mieri M, Hamburger M, Mennet-von Eiff M, Potterat O, Schnelle M, Simões-Wüst AP, von Mandach U. Inhibition of porcine detrusor contractility by the flavonoid fraction of Bryophyllum pinnatum--a potential phytotherapeutic drug for the treatment of the overactive bladder syndrome. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2015; 22:158-164. [PMID: 25636885 DOI: 10.1016/j.phymed.2014.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 09/12/2014] [Accepted: 11/15/2014] [Indexed: 06/04/2023]
Abstract
AIMS To determine if the phytotherapeutic agent, Bryophyllum pinnatum, could serve as an alternative drug for the overactive bladder syndrome, and to characterise the fraction responsible for the inhibition of detrusor contractility. METHODS Fractions were prepared from the MeOH extract of B. pinnatum and further analysed by HPLC-PDA-MS. Detrusor muscle strips were prepared from porcine bladders and the electrically induced muscle contractility measured by organ bath. The effect of B. pinnatum leaf press juice (2.5-10%), a flavonoid fraction (0.1-1 mg/ml), and a bufadienolide fraction (0.1-40 μg/ml) on detrusor contractility was assessed and compared with controls (polar fraction (0.5-5 mg/ml) and oxybutynin (10(-8)-10(-6) M)). RESULTS The press juice, at a concentration of 10% led to a reduction of detrusor contractility. Bladder strips treated with the flavonoid fraction showed a significant reduction of the contractility to 21.3 ± 5.2% (1 mg/ml) while the bufadienolide fraction had no inhibitory effect in the investigated concentrations. The polar fraction showed a reduction of the contractility in a pH-dependent fashion. At 10(-6) M concentration oxybutynin reduced the detrusor contractility to 21.9 ± 4.7%. CONCLUSIONS The flavonoid fraction of Bryophyllum pinnatum reduces the porcine detrusor contractility in a dose- and time-dependent manner. Fractions from B. pinnatum may be a new pharmacological approach for the treatment of OAB.
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Affiliation(s)
- K Fürer
- Department of Obstetrics, University Hospital Zurich, CH-8091 Zurich, Switzerland; Division of Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, CH-4056 Basel, Switzerland
| | - D Eberli
- Urology Clinic, University Hospital Zurich, CH-8091 Zurich, Switzerland
| | - C Betschart
- Department of Gynaecology, University Hospital Zurich, CH-8091 Zurich, Switzerland
| | - R Brenneisen
- Department of Clinical Research, University of Bern, CH-3010 Bern, Switzerland
| | - M De Mieri
- Division of Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, CH-4056 Basel, Switzerland
| | - M Hamburger
- Division of Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, CH-4056 Basel, Switzerland
| | | | - O Potterat
- Division of Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, CH-4056 Basel, Switzerland
| | - M Schnelle
- Weleda AG, CH-4144 Arlesheim, Switzerland
| | - A P Simões-Wüst
- Research Department, Paracelsus Hospital Richterswil, CH-8805 Richterswil, Switzerland
| | - U von Mandach
- Department of Obstetrics, University Hospital Zurich, CH-8091 Zurich, Switzerland.
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Fry CH, Jabr RI. T-type Ca2+ channels and the urinary and male genital tracts. Pflugers Arch 2014; 466:781-9. [PMID: 24463704 DOI: 10.1007/s00424-014-1446-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 01/06/2014] [Accepted: 01/07/2014] [Indexed: 11/26/2022]
Abstract
T-type Ca(2+) channels are widely expressed throughout the urinary and male genital tracts, generally alongside L-type Ca(2+) channels. The use of pharmacological blockers of these channels has suggested functional roles in all regions, with the possible exception of the ureter. Their functional expression is apparent not just in smooth muscle cells but also in interstitial cells that lie in close proximity to muscle, nerve and epithelial components of these tissues. Thus, T-type Ca(2+) channels can contribute directly to modulation of muscle function and indirectly to changes of epithelial and nerve function. T-type Ca(2+) channel activity modulates phasic contractile activity, especially in conjunction with Ca(2+)-activated K(+) channels, and also to agonist-dependent responses in different tissues. Upregulation of channel density occurs in pathological conditions associated with enhanced contractile responses, e.g. overactive bladder, but it is unclear if this is causal or a response to the pathological state. Moreover, T-type Ca(2+) channels may have a role in the development of prostate tumours regulating the secretion of mitogens from neuroendocrine cells. Although a number of selective channel blockers exist, their relative selectivity over L-type Ca(2+) channels is often low and makes evaluation of T-type Ca(2+) channel function in the whole organism difficult.
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Affiliation(s)
- C H Fry
- Department of Biochemistry and Physiology, University of Surrey, Guildford, GU2 7XH, UK,
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Igawa Y, Kumano S, Aizawa N, Saito Y, Ito H, Watanabe S, Takahashi N, Tajimi M, Nishimatsu H, Homma Y. Changes in the function and expression of T-type and N-type calcium channels in the rat bladder after bladder outlet obstruction. J Urol 2013; 191:1159-67. [PMID: 24120720 DOI: 10.1016/j.juro.2013.10.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/02/2013] [Indexed: 11/30/2022]
Abstract
PURPOSE We evaluated possible changes in the function and expression of T-type and N-type Ca(2+) channels in the bladder of rats with bladder outlet obstruction. MATERIALS AND METHODS Female Sprague Dawley® rats were divided into a group with bladder outlet obstruction created by partial urethral ligation and a sham operated group. Six weeks postoperatively we determined the mRNA expression of T-type and N-type Ca(2+) channels in the bladder, dorsal root ganglion and spinal cord. We also cystometrically investigated expression by intravenous administration of the T-Ca blocker RQ-00311610 or the N-type Ca(2+) channel blocker ω-conotoxin GVIA. We then performed in vitro functional studies of detrusor strips using these blockers. RESULTS mRNA expression of T-type Ca(2+) channels in the bladder detrusor and mucosa layers, and the spinal cord dorsal horn, and N-type Ca(2+) channels in the whole bladder and detrusor layer, and the spinal cord dorsal horn was greater in the obstructed group than the sham operated group. In obstructed rats bladder capacity and voided volume increased after RQ-00311610 administration but the number of nonvoiding contractions decreased after ω-conotoxin GVIA administration. Detrusor strips from obstructed rats showed weaker contractile responses to electrical field stimulation, particularly in regard to the purinergic component. ω-Conotoxin GVIA suppressed electrical field stimulation induced contractions only in the detrusor of obstructed rats, especially the cholinergic component. CONCLUSIONS Blocking T-type Ca(2+) channels increased bladder capacity while N-type Ca(2+) channel blockade inhibited nonvoiding contractions in rats with bladder outlet obstruction. Decreased bladder efferent neurotransmission occurred after bladder outlet obstruction, predominantly in its purinergic component and detrusor contractions via cholinergic neurotransmission were activated in a compensatory manner, probably via N-type Ca(2+) channel up-regulation.
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Affiliation(s)
- Yasuhiko Igawa
- Department of Continence Medicine, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
| | - Shintaro Kumano
- University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Naoki Aizawa
- Department of Continence Medicine, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Yasuho Saito
- Department of Urology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Hiroki Ito
- Department of Continence Medicine, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | | | | | | | - Hiroaki Nishimatsu
- Department of Urology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Yukio Homma
- Department of Urology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
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Jiang X, Luttrell I, Chitaley K, Yang CC. T- and L-Type Voltage-Gated Calcium Channels: Their Role in Diabetic Bladder Dysfunction. Neurourol Urodyn 2013; 33:147-52. [DOI: 10.1002/nau.22391] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Accepted: 02/07/2013] [Indexed: 01/15/2023]
Affiliation(s)
- Xiaogang Jiang
- Department of Urology; University of Washington; Seattle, Washington
| | - Ian Luttrell
- Department of Urology; University of Washington; Seattle, Washington
| | - Kanchan Chitaley
- Department of Urology; University of Washington; Seattle, Washington
| | - Claire C. Yang
- Department of Urology; University of Washington; Seattle, Washington
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Inhibitory effects of the ATP-sensitive potassium channel openers cromakalim, pinacidil and minoxidil on the carbachol-response curve in porcine detrusor muscle. Arab J Urol 2012; 10:207-15. [PMID: 26558027 PMCID: PMC4442889 DOI: 10.1016/j.aju.2011.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 12/13/2011] [Accepted: 12/14/2011] [Indexed: 12/05/2022] Open
Abstract
Aims ATP-sensitive potassium channels represent promising drug targets for treating specific bladder diseases. The inhibitory effects of ATP-selective potassium channel openers (PCOs) on the carbachol–response curve in porcine detrusor muscle were examined. Materials and methods Each of the three substances used in the study represent one prototype of a different class of PCO: cromakalim belongs to the benzopyran series, pinacidil is a cyanoguanidine derivative, and minoxidil represents a pyrimidine derivative. The porcine detrusor muscle represents one of the best models for human detrusor. Experiments were conducted on muscle strips of porcine detrusor muscle suspended in a tissue bath. Concentration–response curves of carbachol were constructed after pretreatment with cromakalim at 10−7, 10−6 and 10−5 M, and with pinacidil and minoxidil at 10−6, 10−5.5 and 10−5 M, respectively. Each muscle strip was only used to examine one concentration of one substance. Results Cromakalim had the greatest inhibitory effect, significantly suppressing the carbachol–response curve at 10−6 and 10−5 M. Pinacidil showed a significant inhibitory effect at 10−5.5 and 10−5 M, which was smaller than that of cromakalim. Minoxidil did not significantly inhibit the contractions at all examined concentrations. Conclusions The examined ATP-sensitive PCOs belonging to the benzopyrans and cyanoguanidines significantly suppressed detrusor contractions. The development of derivatives of these prototypes could open new possibilities for the pharmacological treatment of selected bladder diseases.
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Adermark L. Modulation of endocannabinoid-mediated long-lasting disinhibition of striatal output by cholinergic interneurons. Neuropharmacology 2011; 61:1314-20. [PMID: 21839753 DOI: 10.1016/j.neuropharm.2011.07.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Revised: 07/22/2011] [Accepted: 07/25/2011] [Indexed: 12/22/2022]
Abstract
The frequency and duration of glutamatergic inputs to the striatum are strong determinants of the net effect of retrograde endocannabinoid (eCB) signaling, and key factors in determining if long-term depression (LTD) has a net disinhibitory or inhibitory action in striatum. Low to moderate frequency stimulation in the dorsolateral striatum elevates eCB levels to an extent that primarily depresses transmitter release at inhibitory synapses, leading to a long-lasting disinhibition (DLL) of synaptic output. The aim of this study was to further characterize the basic features of endocannabinoid-mediated DLL of striatal output induced by moderate frequency stimulation (5 Hz, 60 s). DLL was inhibited in slices treated with the group 1 metabotropic glutamate receptor (mGluR) antagonists MPEP (40 μM) and CPCCOEt (40 μM), the dopamine D2 receptor antagonist sulpiride (5 μM), the L-type calcium channel blocker nifedipine (20 μM), the nicotinic receptor antagonist mecamylamine (10 μM), the muscarinic agonist oxotremorine sesquifumarate (10 μM), and strychnine (0.1 μM). Strychnine did not block DLL induced by WIN55,212-2 (250 nM), showing that glycine receptor-mediated modulation of eCB signaling occurs upstream from CB(1)R activation. Scopolamine (10 μM) restored DLL in strychnine-treated slices, suggesting that inhibition of glycine receptors on cholinergic interneurons could modulate eCB signaling by enhancing muscarinic receptor activation and reducing the opening of L-type calcium channels in response to depolarization. These data suggests that similar activation points are required for stimulation-induced DLL as for LTD at excitatory striatal synapses, and that cholinergic interneurons are key modulators of stimulation-induced eCB signaling in the striatum.
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Affiliation(s)
- Louise Adermark
- Addiction Biology Unit, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, University of Gothenburg, Box 410, 405 30 Gothenburg, Sweden.
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Badawi JK, Ding A, Bross S. Inhibitory effects of different ATP-sensitive potassium channel openers on electrically generated and carbachol-induced contractions of porcine and human detrusor muscle. Fundam Clin Pharmacol 2008; 22:75-86. [PMID: 18251724 DOI: 10.1111/j.1472-8206.2007.00558.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The inhibitory effects of different potassium channel openers (PCOs) on electrically generated and carbachol-induced contractions of porcine and human detrusor muscle were examined. PCOs could be an interesting substance class for treatment of detrusor overactivity. Experiments were performed on muscle strips suspended in a tissue bath. Human tissue originated from patients who underwent total cystectomy. The concentration-relaxation curves of the first-generation PCOs cromakalim and pinacidil and the untypical PCO minoxidil were performed using carbachol-precontracted detrusor muscle strips of pigs and humans. Additionally, the inhibitory effects of cromakalim, pinacidil and minoxidil on electrically generated contractions of porcine detrusor muscle were examined. Furthermore, the inhibitory effect of the second-generation, bladder-selective PCO ZM 226600 on electrically generated contractions of the human detrusor muscle was determined. Frequency-response curves were performed before and after incubation with one PCO used in two different concentrations. In humans, cromakalim and pinacidil led to a maximum decrease of 73.5 and 68.4% and showed mean pD2 values of 6.65 and 5.5, respectively. In pigs, cromakalim and pinacidil led to a maximum decrease of 90.6 and 93.6% and showed mean pD2 values of 6.39 and 5.01, respectively. Minoxidil did not significantly decrease the precontraction at the highest used concentration in both species. Cromakalim exhibited the biggest inhibitory effect being significant at 10(-5) and 10(-6) M. Pinacidil showed only a significant inhibitory effect at 10(-5) M which was smaller than that of cromakalim. At 3 x 10(-6) M only a very small effect occurred at 1 Hz. Minoxidil did not inhibit the contractions at both examined concentrations except for a very small effect at 1 Hz. In humans, ZM 226600 exhibited at 10(-6) and 10(-5) M a significant inhibitory effect. At 10(-7) M it was only significant at one frequency.
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Affiliation(s)
- Jasmin Katrin Badawi
- Department of Urology, Otto-von-Guericke-University Magdeburg, Leipziger Strasse 44, D-39120 Magdeburg, Germany.
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