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Uta D, Hattori T, Yoshimura M. Analyses of the Mode of Action of an Alpha-Adrenoceptor Blocker in Substantia Gelatinosa Neurons in Rats. Int J Mol Sci 2021; 22:9636. [PMID: 34502543 PMCID: PMC8431806 DOI: 10.3390/ijms22179636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/24/2021] [Accepted: 09/03/2021] [Indexed: 11/17/2022] Open
Abstract
To elucidate why naftopidil increases the frequency of spontaneous synaptic currents in only some substantia gelatinosa (SG) neurons, post-hoc analyses were performed. Blind patch-clamp recording was performed using slice preparations of SG neurons from the spinal cords of adult rats. Spontaneous inhibitory and excitatory postsynaptic currents (sIPSCs and sEPSCs, respectively) were recorded. The ratios of the frequency and amplitude of the sIPSCs and sEPSCs following the introduction of naftopidil compared with baseline, and after the application of naftopidil, serotonin (5-HT), and prazosin, compared with noradrenaline (NA) were evaluated. First, the sIPSC analysis indicated that SG neurons reached their full response ratio for NA at 50 μM. Second, they responded to 5-HT (50 μM) with a response ratio similar to that for NA, but prazosin (10 μM) did not change the sEPSCs and sIPSCs. Third, the highest concentration of naftopidil (100 μM) led to two types of response in the SG neurons, which corresponded with the reactions to 5-HT and prazosin. These results indicate that not all neurons were necessarily activated by naftopidil, and that the micturition reflex may be regulated in a sophisticated manner by inhibitory mechanisms in these interneurons.
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Affiliation(s)
- Daisuke Uta
- Department of Applied Pharmacology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Tsuyoshi Hattori
- Department of Medical Affairs, Asahi Kasei Pharma Corporation, Tokyo 100-0006, Japan
| | - Megumu Yoshimura
- Department of Orthopedic Surgery, Nakamura Hospital, Fukuoka 822-0002, Japan;
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Kitta T, Chiba H, Kanno-Kakibuchi Y, Hattori T, Higuchi M, Ouchi M, Togo M, Abe-Takahashi Y, Michishita M, Kitano T, Shinohara N. Long-term administration of alpha-1 blocker can reverse the micturition pattern in a bladder outlet obstruction murine model. Int J Urol 2020; 27:1150-1156. [PMID: 32985003 DOI: 10.1111/iju.14377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/24/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To investigate the effect of chronic administration of an alpha-1 blocker on micturition patterns in long-term partial bladder outlet obstruction. METHODS Mice were divided into three groups: a normal group, in which animals were fed a standard diet; a partial bladder outlet obstruction group, in which the proximal urethra was tied and animals were fed a standard diet; and a partial bladder outlet obstruction + naftopidil group, in which the proximal urethra was tied and animals were fed a standard diet containing naftopidil. Micturition behavior was evaluated in all groups for 6 months after partial bladder outlet obstruction surgery. The parameters evaluated included voided volume, time per void, urination frequency and total urine volume. Quantitative assessment of gene expression was also carried out. RESULTS Total urine volume, as well as total and average voided volume during night, was significantly decreased in partial bladder outlet obstruction + naftopidil mice compared with partial bladder outlet obstruction animals. The levels of transcripts encoding 5-hydroxytryptamine 2A and tissue inhibitor of metalloproteinase 2 were significantly decreased in the partial bladder outlet obstruction + naftopidil group compared with the partial bladder outlet obstruction group. CONCLUSIONS Long-term administration of an alpha-1 blocker seems to reverse the disturbance of the micturition pattern caused by partial bladder outlet obstruction. Mechanistically, this effect might be mediated by changes in the expression of a serotonin receptor and/or in the activity of the fibrogenesis pathway.
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Affiliation(s)
- Takeya Kitta
- Department of Renal and Genitourinary Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Hiroki Chiba
- Department of Renal and Genitourinary Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yukiko Kanno-Kakibuchi
- Department of Renal and Genitourinary Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Tsuyoshi Hattori
- Department of Medical Affairs, Asahi Kasei Pharma Corporation, Tokyo, Japan
| | - Madoka Higuchi
- Department of Renal and Genitourinary Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Mifuka Ouchi
- Department of Renal and Genitourinary Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Mio Togo
- Department of Renal and Genitourinary Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yui Abe-Takahashi
- Department of Renal and Genitourinary Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Mai Michishita
- Laboratory for Pharmacology, Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, Tokyo, Japan
| | - Tatsuya Kitano
- Laboratory for Pharmacology, Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, Tokyo, Japan
| | - Nobuo Shinohara
- Department of Renal and Genitourinary Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
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Sugaya K, Nishijima S, Kadekawa K, Noguchi K, Woo JT, Yamamoto H, Matsumoto S. Vanilla scent reduces frequency of urination in urethane-anesthetized rats. Low Urin Tract Symptoms 2020; 13:189-193. [PMID: 32871621 DOI: 10.1111/luts.12346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/05/2020] [Accepted: 08/13/2020] [Indexed: 12/01/2022]
Abstract
OBJECTIVES The scent of vanilla has a relaxing effect and is used to treat sleep disorders. Sleep disorders can both cause and be caused by nocturia. Therefore, we examined whether vanilla inhalation would reduce the frequency of urination in rats under light urethane anesthesia. METHODS Twenty-four rats were anesthetized with 0.6 g/kg urethane subcutaneously (half the usual dose) to induce a sleep-like state. In 12 rats, continuous cystometry was performed via a transurethral catheter before, during and after inhalation of vanilla (n = 7) or the citrus fruit shiikuwasa (n = 5) for 60 minutes. The remaining 12 rats did not undergo cystometry but underwent vanilla inhalation treatment for 60 minutes (n = 6), or no inhalation treatment (n = 6); blood was then collected from these two groups and serum monoamine levels were compared. RESULTS Intervals between bladder contractions were significantly longer after vanilla inhalation than before. However, baseline bladder pressure, maximum bladder contraction pressure, and residual volume remained unchanged. During shiikuwasa inhalation, the body movement of each rat increased but cystometric parameters did not change. Serum concentrations of adrenaline, noradrenaline and dopamine, but not serotonin, were significantly lower in rats that had inhaled vanilla than in those that had not. CONCLUSIONS Vanilla scent decreased serum catecholamine levels and urination frequency in rats under light urethane anesthesia. These results suggest that the scent of vanilla may reduce nocturia.
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Affiliation(s)
| | | | | | | | - Je T Woo
- Okinawa Research Center, Okinawa, Japan
| | - Hideyuki Yamamoto
- Department of Biochemistry Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Seiji Matsumoto
- Center for Advanced Research and Education, Asahikawa Medical University, Asahikawa, Japan
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Differential Effects of Alpha 1-Adrenoceptor Antagonists on the Postsynaptic Sensitivity: Using Slice Patch-Clamp Technique for Inhibitory Postsynaptic Current in Substantia Gelatinosa Neurons From Lumbosacral Spinal Cord in Rats. Int Neurourol J 2020; 24:127-134. [PMID: 32615674 PMCID: PMC7332814 DOI: 10.5213/inj.1938248.124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/30/2020] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Alpha1-adrenoceptors participate in improving storage symptoms of male lower urinary tract symptoms. However, the mechanism of action of these compounds remains unclear. The goal of the present study was to clarify the effect of α1- adrenoceptor antagonists on γ-aminobutyric acid (GABA)/glycine-mediated outward currents of the inhibitory postsynaptic current (IPSC) in substantia gelatinosa (SG) neurons from the lumbosacral spinal cord in rats. METHODS Male adult Sprague-Dawley rats were used. Blind whole-cell patch-clamp recordings were performed in SG neurons from isolated spinal cord slice preparations. IPSCs were recorded in individual SG neurons to which naftopidil (100μM), tamsulosin (100μM), silodosin (30μM), or prazosin (10μM) were applied sequentially with intervening washout periods. Strychnine (2μM), bicuculline (10μM), or tetrodotoxin (TTX)(1μM) were added before naftopidil. Individual outward currents were analyzed. RESULTS The bath application of naftopidil, yielded outward IPSCs in 13 of 52 SG neurons. The naftopidil response was unchanged in the presence of TTX. Regression analysis of the outward currents between the 1st and 2nd applications of naftopidil revealed a Pearson correlation coefficient of 0.996 with a line slope of 0.983. The naftopidil-induced outward current was attenuated in the presence of strychnine and/or bicuculline. The GABA/glycine-mediated outward currents induced by tamsulosin, silodosin, and prazosin were smaller than those obtained with naftopidil. CONCLUSION Naftopidil-induced GABA/glycine-mediated outward currents in a subset of SG neurons prepared from the L6- S1 level of rat spinal cord. The results indicated that α1-adrenoceptor antagonists, particularly naftopidil, induce neural suppression (in part) by mediating hyperpolarization. The response is associated with glycinergic and/or GABAergic neural transmission. Naftopidil may suppress the micturition reflex and improve urinary storage symptoms as a subsidiary effect resulting from hyperpolarization in SG neurons of the spinal cord.
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Effect of Alpha 1-Adrnoceptor Antagonists on Postsynaptic Sensitivity in Substantia Gelatinosa Neurons From Lumbosacral Spinal Cord in Rats Using Slice Patch-Clamp Technique for mEPSC. Int Neurourol J 2020; 24:135-143. [PMID: 32615675 PMCID: PMC7332821 DOI: 10.5213/inj.1938250.125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 02/18/2020] [Indexed: 02/02/2023] Open
Abstract
Purpose Alpha1-adrenoceptors participate in improving storage symptoms of male lower urinary tract symptoms (LUTS). However, the mechanism of action of these compounds remains unclear. To clarify the mechanism of the α1-adrenoceptor antagonists, the amplitude of miniature excitatory postsynaptic currents (mEPSCs) was analyzed in the lumbosacral spinal cord in rats. Methods Male adult Sprague-Dawley rats were used. Blind whole-cell patch-clamp recordings were performed on substantia gelatinosa (SG) neurons in spinal cord slice preparations. The amplitude of mEPSCs was recorded in individual SG neurons to which α1-adrenoceptors (100μM naftopidil, 100μM tamsulosin, and 30μM silodosin) were applied sequentially with intervening washout periods. Individual amplitudes were analyzed. Results Pearson correlation coefficients (r) for the amplitudes of mEPSCs between the baseline and postadministration of α1-adrenoceptor antagonists indicated changes of the amplitude ranked in the order of naftopidil (r =0.393), tamsulosin (r=0.738), and silodosin (r=0.944). Together, the α1-adrenoceptor antagonists yielded significant increases in the amplitude of mEPSCs in SG neurons (n=108, P=0.012). However, the effects of each α1-adrenoceptor antagonist on the amplitude were as follows (relative to the baseline; n=36 each): naftopidil, P=0.129; tamsulosin, P=0.201; and silodosin, P=0.005. The rate of response to naftopidil for the outward current was relatively high among the α1-adrenoceptor blockers. An inward current was observed only with the naftopidil application. Conclusions Alpha1-adrenoceptor antagonists changed the amplitudes of mEPSCs in a subset of SG neurons in slices prepared from the L6–S1 levels of rat spine. Although the α1-adrenoceptor antagonists generated inward or outward currents in the SG neurons, different rates of response were observed with each antagonist. These results are important for understanding the mechanisms of action (at the spinal level) of α1-adrenoceptor antagonists for the storage symptoms of male LUTS.
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In Vitro Effects of Plasma Collected From Rats Administered Naftopidil on Whole Urinary Bladder Preparation Isolated From Rats. Int Neurourol J 2020; 23:277-286. [PMID: 31905274 PMCID: PMC6944793 DOI: 10.5213/inj.1938102.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 09/29/2019] [Indexed: 11/08/2022] Open
Abstract
Purpose Alpha-1-adrenoceptor blockers (e.g., naftopidil) are prescribed for the treatment of male lower urinary tract symptoms. Although the mechanism of action of naftopidil has been studied in various organs, that in the urinary bladder remains unknown. To clarify the direct effects of naftopidil on this organ, activities were assessed in the isolated rat whole urinary bladder. Methods A total of 30 female rats were used. In Experiment 1, bladder activity was measured during a cumulative administration of 2.5–75μM naftopidil (n=7). In Experiment 2, rats were divided into 2 groups: control (n=10) and naftopidil (5 mg/animal/day, oral gavage, once-daily for 2 weeks) (n=13). After the treatment period, plasma was obtained from each rat. The urinary bladders were harvested from the control rats. Isovolumetric rhythmic bladder contractions were induced at above the threshold volume, and intravesical pressure was recorded. Control plasma was added to the organ bath; after subsequent wash-out, plasma collected from rats administered naftopidil was added. In Experiment 3, the plasma levels of monoamines and amino acids were quantified using the individual plasma prepared in the Experiment 2. Results Cumulative dosing with naftopidil did not change the interval between spontaneous contractions compared to the interval at baseline. After adding control plasma, the interval was shortened compared to the baseline (P=0.008). The plasma collected from rats administered naftopidil suppressed the shortening of the interval compared to the control plasma (P=0.041). Naftopidil resulted in a decrease in the level of noradrenaline (P=0.009) and an increase in that of glycine (P=0.014). Conclusions Although naftopidil did not directly act on the interval between spontaneous contractions of the urinary bladder, the plasma collected from rats administered naftopidil, with changing levels of monoamines and amino acids, may suppressed shortening the interval.
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Steuer I, Guertin PA. Central pattern generators in the brainstem and spinal cord: an overview of basic principles, similarities and differences. Rev Neurosci 2019; 30:107-164. [PMID: 30543520 DOI: 10.1515/revneuro-2017-0102] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/30/2018] [Indexed: 12/11/2022]
Abstract
Central pattern generators (CPGs) are generally defined as networks of neurons capable of enabling the production of central commands, specifically controlling stereotyped, rhythmic motor behaviors. Several CPGs localized in brainstem and spinal cord areas have been shown to underlie the expression of complex behaviors such as deglutition, mastication, respiration, defecation, micturition, ejaculation, and locomotion. Their pivotal roles have clearly been demonstrated although their organization and cellular properties remain incompletely characterized. In recent years, insightful findings about CPGs have been made mainly because (1) several complementary animal models were developed; (2) these models enabled a wide variety of techniques to be used and, hence, a plethora of characteristics to be discovered; and (3) organizations, functions, and cell properties across all models and species studied thus far were generally found to be well-preserved phylogenetically. This article aims at providing an overview for non-experts of the most important findings made on CPGs in in vivo animal models, in vitro preparations from invertebrate and vertebrate species as well as in primates. Data about CPG functions, adaptation, organization, and cellular properties will be summarized with a special attention paid to the network for locomotion given its advanced level of characterization compared with some of the other CPGs. Similarities and differences between these networks will also be highlighted.
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Affiliation(s)
- Inge Steuer
- Neuroscience Unit, Laval University Medical Center (CHUL - CHU de Québec), 2705 Laurier Blvd, Quebec City, Quebec G1V 4G2, Canada
| | - Pierre A Guertin
- Neuroscience Unit, Laval University Medical Center (CHUL - CHU de Québec), 2705 Laurier Blvd, Quebec City, Quebec G1V 4G2, Canada
- Faculty of Medicine, Department of Psychiatry and Neurosciences, Laval University, Quebec City, Quebec G1V 0A6, Canada
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Emotional Stress Facilitates Micturition Reflex: Possible Inhibition by an α1-Adrenoceptor Blocker in the Conscious and Anesthetized State. Int Neurourol J 2019; 23:100-108. [PMID: 31260609 PMCID: PMC6606938 DOI: 10.5213/inj.1836284.142] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 03/27/2019] [Indexed: 12/28/2022] Open
Abstract
Purpose To test the hypothesis that naftopidil prolongs intercontraction intervals in rats undergoing chronic stress as observed in previous animal models, voiding behavior and bladder function were measured and analyzed. Methods Female Sprague-Dawley rats weighing 200–230 g were exposed to repeated variate stress (RVS) for 1 week, chronic variable mild stress for 2 weeks, or simple mild stress for 1 week. Voiding behavior was assessed in metabolic cages. Voiding frequency and urine output were measured, and changes of these values were compared for the different types of stress. Micturition reflex was analyzed using unconscious cystometry. Naftopidil was administered orally at 30 mg/kg/day for 2 weeks. Results Unexpectedly, no stress-exposed rats exhibited increased micturition frequency compared to the normal nonstressed control. However, intercontraction intervals were shortened with each type of stress in the unconscious condition, especially by RVS (P<0.01). Naftopidil prolonged the shortened intervals. Conclusions Although voiding behavior appears approximately normal in rats chronically exposed to emotional stress, internal bladder function can be affected. With anesthesia, micturition intervals were moderately shortened by emotional stress and clearly improved by naftopidil. Therefore, naftopidil appears to act at the spinal level at least.
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Characterization on Responsiveness of Excitatory Synaptic Transmissions to α1-Adrenoceptor Blockers in Substantia Gelatinosa Neurons Isolated From Lumbo-Sacral Level in Rat Spinal Cords. Int Neurourol J 2019; 23:13-21. [PMID: 30943690 PMCID: PMC6449664 DOI: 10.5213/inj.1938056.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 03/10/2019] [Indexed: 12/14/2022] Open
Abstract
Purpose The aim of this study was to characterize the responsiveness of miniature excitatory postsynaptic currents (mEPSCs) to α1-adrenoceptor blockers in substantia gelatinosa (SG) neurons from the spinal cord to develop an explanation for the efficacy of α1-adrenoceptor blockers in micturition dysfunction. Methods Male adult Sprague-Dawley rats were used. Blind whole-cell patch-clamp recordings were performed using SG neurons in spinal cord slices. Naftopidil (100μM), tamsulosin (100μM), or silodosin (30μM), α1-adrenoceptor blockers, was perfused. The frequency of mEPSCs was recorded in an SG neuron to which the 3 blockers were applied sequentially with wash-out periods. Individual frequencies in a pair before naftopidil and tamsulosin perfusion were plotted as baseline, and the correlation between them was confirmed by Spearman correlation coefficient; linear regression was then performed. The same procedure was performed before naftopidil and silodosin perfusion. Frequencies of pairs after naftopidil and tamsulosin perfusion and after naftopidil and silodosin perfusion were similarly analyzed. The ratios of the frequencies after treatment to before were then calculated. Results After the treatments, Spearman ρ and the slope were decreased to 0.682 from 0.899 at baseline and 0.469 from 1.004 at baseline, respectively, in the tamsulosin group relative to the naftopidil group. In the silodosin group, Spearman ρ and the slope were also decreased to 0.659 from 0.889 at baseline and 0.305 from 0.989 at baseline, respectively, relative to the naftopidil group. Naftopidil significantly increased the ratio of the frequency of mEPSCs compared to tamsulosin and silodosin (P=0.015 and P=0.004, respectively). Conclusions There was a difference in responsiveness in the frequency of mEPSCs to α1-adrenoceptor blockers, with the response to naftopidil being the greatest among the α1-adrenoceptor blockers. These data are helpful to understand the action mechanisms of α1-adrenoceptor blockers for male lower urinary tract symptoms in clinical usage.
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Effects of High Concentrations of Naftopidil on Dorsal Root-Evoked Excitatory Synaptic Transmissions in Substantia Gelatinosa Neurons In Vitro. Int Neurourol J 2018; 22:252-259. [PMID: 30599496 PMCID: PMC6312966 DOI: 10.5213/inj.1836146.073] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/18/2018] [Indexed: 01/21/2023] Open
Abstract
Purpose Naftopidil ((±)-1-[4-(2-methoxyphenyl) piperazinyl]-3-(1-naphthyloxy) propan-2-ol) is prescribed in several Asian countries for lower urinary tract symptoms suggestive of benign prostatic hyperplasia. Previous animal experiments showed that intrathecal injection of naftopidil abolished rhythmic bladder contraction in vivo. Naftopidil facilitated spontaneous inhibitory postsynaptic currents in substantia gelatinosa (SG) neurons in spinal cord slices. These results suggest that naftopidil may suppress the micturition reflex at the spinal cord level. However, the effect of naftopidil on evoked excitatory postsynaptic currents (EPSCs) in SG neurons remains to be elucidated. Methods Male Sprague-Dawley rats at 6 to 8 weeks old were used. Whole-cell patch-clamp recordings were made using SG neurons in spinal cord slices isolated from adult rats. Evoked EPSCs were analyzed in Aδ or C fibers. Naftopidil or prazosin, an α1-adrenoceptor blocker, was perfused at 100 μM or 10 μM, respectively. Results Bath-applied 100 μM naftopidil significantly decreased the peak amplitudes of Aδ and C fiber-evoked EPSCs to 72.0%±7.1% (n=15) and 70.0%±5.5% (n=20), respectively, in a reversible and reproducible manner. Bath application of 10μM prazosin did not inhibit Aδ or C fiber-evoked EPSCs. Conclusions The present study suggests that a high concentration of naftopidil reduces the amplitude of evoked EPSCs via a mechanism that apparently does not involve α1-adrenoceptors. Inhibition of evoked EPSCs may also contribute to suppression of the micturition reflex, together with nociceptive stimulation.
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Kawatani M, Akimoto N, Yamada A, Furue H, Kawatani M. Noradrenergic effects in rat sacral autonomic nucleus using in vitro slice patch-clamp recordings. Biomed Res 2018; 38:359-369. [PMID: 29225214 DOI: 10.2220/biomedres.38.359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Noradrenergic modulation has been frequently discussed in the context of neural activities that are related to pelvic organs. The sacral preganglionic nucleus (SPN) is a spinal nucleus containing parasympathetic preganglionic neurons that send fibers to pelvic nerves. In spite of the abundant presence of noradrenergic fibers around the SPN, the effects of noradrenaline (NA) remain obscure. To explore this issue, NA (50 μM) was applied to parasympathetic preganglionic neurons in the SPN during whole-cell patch clamp recording. The SPN was labeled with the retrograde tracer, DiI. These neurons demonstrated two classes of firing patterns (delayed and regular) in terms of initiation of firing. Independent of these firing patterns, NA induced inward (56%) or outward (32%) currents in labeled SPN neurons. Phenylephrine, an α1 receptor agonist, induced an inward current, and clonidine, an α2 receptor agonist, induced an outward current, indicating the existence of both α1 and α2 adrenoreceptors in DiI-labeled SPN neurons. NA also modulated synaptic currents according to the firing patterns. In delayed firing neurons, NA inhibited both spontaneous excitatory post-synaptic currents (sEPSCs) and spontaneous inhibitory post-synaptic currents (sIPSCs). Hence, NA facilitated sEPSCs and sIPSCs in about a half of regular firing neurons. Bath application of phenylephrine facilitated sEPSCs and sIPSCs, and clonidine inhibited them. These results support the hypothesis of multiple effects of NA in the SPN, and may suggest functional differences among SPN neurons.
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Affiliation(s)
| | - Nozomi Akimoto
- Department of Information Physiology, National Institute for Physiological Sciences
| | - Akihiro Yamada
- Department of Information Physiology, National Institute for Physiological Sciences
| | - Hidemasa Furue
- Department of Information Physiology, National Institute for Physiological Sciences
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Mechanisms of action for α1-adrenoceptor blockers in storage symptoms with new insights into the micturition reflex. Life Sci 2017; 191:90-96. [DOI: 10.1016/j.lfs.2017.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/07/2017] [Accepted: 10/11/2017] [Indexed: 01/22/2023]
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Effects of naftopidil on inhibitory transmission in substantia gelatinosa neurons of the rat spinal dorsal horn in vitro. J Neurol Sci 2017; 380:205-211. [DOI: 10.1016/j.jns.2017.07.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/07/2017] [Accepted: 07/22/2017] [Indexed: 01/14/2023]
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Effect of naftopidil on brain noradrenaline-induced decrease in arginine-vasopressin secretion in rats. J Pharmacol Sci 2016; 132:86-91. [DOI: 10.1016/j.jphs.2016.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/28/2016] [Accepted: 08/29/2016] [Indexed: 11/18/2022] Open
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Sugaya K, Nishijima S, Kadekawa K, Ashitomi K, Ueda T, Yamamoto H. Naftopidil improves locomotor activity and urinary frequency in rats with pelvic venous congestion. Biomed Res 2016; 37:221-6. [PMID: 27544997 DOI: 10.2220/biomedres.37.221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The α1D/A receptor antagonist, naftopidil, inhibits micturition reflex by acting on various different sites. We examined the effects of naftopidil on bladder activity and changes in the induced urinary frequency using female rats with pelvic venous congestion (PC). Twenty-four female rats were divided into sham, PC, and PC/naftopidil groups. After anesthetizing rats in the PC and PC/naftopidil groups, the bilateral common iliac veins and uterine veins were ligated. Rats in the sham and PC groups were fed a standard diet, while rats in the PC/naftopidil group were fed diets containing 0.04% naftopidil. After 4 weeks of treatment, locomotor activity, urinary nitric oxide metabolites (NOx), continuous cystometry, and plasma monoamine measurements were performed. PC rats exhibited a decrease of locomotor activity, a shorter interval between bladder contractions on continuous cystometry, and decreased urinary NOx and plasma serotonin levels than the sham rats. The PC/naftopidil rats exhibited an increase of locomotor activity, a longer interval between bladder contractions, and increased urinary NOx and plasma serotonin levels. Therefore, naftopidil might improve bladder dysfunction induced by pelvic venous congestion due to several actions in the central nervous system and bladder tissue, as well as acting as an α1 blocker to cause pelvic venous dilation.
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Sugaya K, Nishijima S, Kadekawa K, Ashitomi K, Ueda T, Yamamoto H, Hattori T. Action of naftopidil on spinal serotonergic neurotransmission for inhibition of the micturition reflex in rats. Neurourol Urodyn 2016; 36:604-609. [DOI: 10.1002/nau.23028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 04/13/2016] [Indexed: 12/23/2022]
Affiliation(s)
| | | | | | | | - Tomoyuki Ueda
- Faculty of Medicine; Institute for Animal Experiments; University of the Ryukyus; Okinawa Japan
| | - Hideyuki Yamamoto
- Department of Biochemistry; Graduate School of Medicine; University of the Ryukyus; Okinawa Japan
| | - Tsuyoshi Hattori
- Department of Medical Affairs; Asahi Kasei Pharma Corporation; Tokyo Japan
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17
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SUGAYA K, NISHIJIMA S, KADEKAWA K, ASHITOMI K, UEDA T, YAMAMOTO H. Naftopidil Improves Symptoms in a Rat Model of Tranilast-Induced Interstitial Cystitis. Low Urin Tract Symptoms 2015; 9:107-110. [DOI: 10.1111/luts.12113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 07/13/2015] [Indexed: 12/01/2022]
Affiliation(s)
| | | | | | | | - Tomoyuki UEDA
- Faculty of Medicine, The Institute for Animal Experiments, University of the Ryukyus; Okinawa Japan
| | - Hideyuki YAMAMOTO
- Department of Biochemistry; Graduate School of Medicine, University of the Ryukyus; Okinawa Japan
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