Stem Cells From Human Exfoliated Deciduous Teeth-Conditioned Medium (SHED-CM) is a Promising Treatment for Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder, characterized by the loss of upper and lower motor neurons, for which an effective treatment has yet to be developed. Previous reports have shown that excessive oxidative stress, related to mitochondrial dysfunction and the accumulation of misfolding protein, contributes to ALS pathology. In terms of treatment, it remains necessary to identify effective medicines for multiple therapeutic targets and have additive effects against several disorders. In this study, we investigated stem cells from human exfoliated deciduous teeth (SHED), which release many factors, such as neurotrophic factors and cytokines, and are applied to treat neurological diseases. Specifically, we examined whether SHED-conditioned medium (CM), i.e., the serum-free culture supernatant of SHED, reduced mutant SOD1-induced intracellular aggregates and neurotoxicity. We found that SHED-CM significantly suppressed the mutant SOD1-induced intracellular aggregates and neurotoxicity. The neuroprotective effects of SHED-CM are partly related to heat shock protein and the activation of insulin-like growth factor-1 receptor. SHED-CM also had a protective effect on induced pluripotent stem cell-derived motor neurons. Moreover, SHED-CM was effective against not only familial ALS but also sporadic ALS. Overall, these results suggest that SHED-CM could be a promising treatment for slowing the progression of ALS.

The neuroprotective effects of activated α7 nicotinic acetylcholine receptor against mutant copper-zinc superoxide dismutase 1-mediated toxicity.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the selective and progressive loss of motor neurons. Although many drugs have entered clinical trials, few have shown effectiveness in the treatment of ALS. Other studies have shown that the stimulation of α7 nicotinic acetylcholine receptor (nAChR) can have neuroprotective effects in some models of neurodegenerative disease, as well as prevent glutamate-induced motor neuronal death. However, the effect of α7 nAChR agonists on ALS-associated mutant copper-zinc superoxide dismutase 1 (SOD1) aggregates in motor neurons remains unclear. In the present study, we examined whether α7 nAChR activation had a neuroprotective effect against SOD1G85R-induced toxicity in a cellular model for ALS. We found that α7 nAChR activation by PNU282987, a selective agonist of α7 nAChR, exhibited significant neuroprotective effects against SOD1G85R-induced toxicity via the reduction of intracellular protein aggregates. This reduction also correlated with the activation of autophagy through the AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) signaling pathway. Furthermore, the activation of α7 nAChRs was found to increase the biogenesis of lysosomes by inducing translocation of the transcription factor EB (TFEB) into the nucleus. These results support the therapeutic potential of α7 nAChR activation in diseases that are characterized by SOD1G85R aggregates, such as ALS.

MicroRNA-5572 Is a Novel MicroRNA-Regulating SLC30A3 in Sporadic Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disease caused by the loss of motor neurons. Although the pathogenesis of sporadic ALS (sALS) remains unclear, it has recently been suggested that disorders of microRNA (miRNA) may be involved in neurodegenerative conditions. The purpose of this study was to investigate miRNA levels in sALS and the target genes of miRNA. Microarray and real-time RT-PCR analyses revealed significantly-decreased levels of miR-139-5p and significantly increased levels of miR-5572 in the spinal cords of sALS patients compared with those in controls. We then focused on miR-5572, which has not been reported in ALS, and determined its target gene. By using TargetScan, we predicted SLC30A3 as the candidate target gene of miR-5572. In a previous study, we found decreased SLC30A3 levels in the spinal cords of sALS patients. We revealed that SLC30A3 was regulated by miR-5572. Taken together, these results demonstrate that the level of novel miRNA miR-5572 is increased in sALS and that SLC30A3 is one of the target genes regulated by miR-5572.

Characteristics and Therapeutic Potential of Dental Pulp Stem Cells on Neurodegenerative Diseases.

To evaluate the therapeutic potential of stem cells for neurodegenerative diseases, emphasis should be placed on clarifying the characteristics of the various types of stem cells. Among stem cells, dental pulp stem cells (DPSCs) are a cell population that is rich in cell proliferation and multipotency. It has been reported that transplantation of DPSCs has protective effects against models of neurodegenerative diseases. The protective effects are not only through differentiation into the target cell type for the disease but are also related to trophic factors released from DPSCs. Recently, it has been reported that serum-free culture supernatant of dental pulp stem cell-conditioned medium (DPCM) contains various trophic factors and cytokines and that DPCM is effective for models of neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Amyotrophic Lateral Sclerosis (ALS). Moreover, the use of stem cells from human exfoliated deciduous teeth (SHEDs) has been considered. SHEDs are derived from deciduous teeth that have been disposed of as medical waste. SHEDs have higher differentiation capacity and proliferation ability than DPSCs. In addition, the serum-free culture supernatant of SHEDs (SHED-CM) contains more trophic factors, cytokines, and biometals than DPCM and also promotes neuroprotection. The neuroprotective effect of DPSCs, including those from deciduous teeth, will be used as the seeds of therapeutic drugs for neurodegenerative diseases. SHEDs will be used for further cell therapy of neurodegenerative diseases in the future. In this paper, we focused on the characteristics of DPSCs and their potential for neurodegenerative diseases.

Mirabegron causes vesical and urethral relaxation in rats with spinal cord injury.

The effects of solifenacin and mirabegron on vesical and urethral function were compared in rats with or without spinal cord injury (SCI). Isovolumetric cystometry and urethral pressure recording were initially performed in intact rats. Then, the bladder neck was ligated under urethane anesthesia, after which a catheter was inserted through the bladder dome for isovolumetric cystometry and another catheter was inserted into the urethra to measure urethral pressure. Solifenacin (0.03-3 mg/kg) or mirabegron (0.03-3 mg/kg) was injected intravenously, and bladder and urethral activity were recorded. To create rats with SCI, the spinal cord was transected at the lower thoracic level under isoflurane anesthesia. After 2 weeks, a catheter was inserted through the bladder dome for single cystometry and bladder activity was recorded without anesthesia following intravenous injection of solifenacin or mirabegron. Isovolumetric cystometry revealed a larger decrease in maximum bladder contraction pressure after injection of solifenacin, whereas prolongation of the interval between bladder contractions was greater with mirabegron. In SCI rats, single cystometry showed that solifenacin and mirabegron both increased bladder volume at the first non-voiding bladder contraction and decreased the maximum bladder contraction pressure. Mirabegron also increased the voided volume and decreased the percentage residual volume without altering bladder capacity. Solifenacin and mirabegron both inhibited bladder contractility, and mirabegron possibly also induced urethral relaxation. Mirabegron may be suitable for patients with overactive bladder and residual urine.

Spinal glycinergic and gamma-aminobutyric acid-ergic neurons inhibit the micturition reflex after electrical stimulation of the perineum in rats with pelvic venous congestion.

OBJECTIVES: To examine whether electrical stimulation of the perineum inhibited urinary frequency in rats with pelvic venous congestion, and whether electrical stimulation influences spinal glycinergic/gamma-aminobutyric acid-ergic neurons. METHODS: Bilateral common iliac veins and bilateral uterine veins were ligated to create pelvic venous congestion rats. At 4 weeks after ligation, cystometry was carried out before and after electrical stimulation with/without intrathecal injection of strychnine (a glycine receptor antagonist) and/or bicuculline (a gamma-aminobutyric acid type A receptor antagonist). In addition, measurement of amino acid levels in the lumbosacral cord was carried out with/without electrical stimulation, and cystometry was carried out after oral administration of glycine. RESULTS: Continuous cystometry showed that the interval between bladder contractions was shorter in pelvic venous congestion rats than in sham rats. Electrical stimulation did not change cystometric parameters in sham rats, but the interval between bladder contractions was increased by electrical stimulation in pelvic venous congestion rats. Electrical stimulation increased the levels of glutamic acid, glycine, gamma-aminobutyric acid, and taurine in the lumbosacral cord of pelvic venous congestion rats. Intrathecal strychnine abolished the effects of electrical stimulation in pelvic venous congestion rats, and intrathecal administration of both strychnine and bicuculline shortened the interval between bladder contractions more than before electrical stimulation. Oral administration of glycine (3%) to pelvic venous congestion rats increased bladder capacity. CONCLUSIONS: Electrical stimulation of the perineum inhibits urinary frequency mainly through activation of spinal glycinergic neurons, and partly through activation of gamma-aminobutyric acid-ergic neurons in a rat model of pelvic venous congestion.

Mechanisms underlying the effects of propiverine on bladder activity in rats with pelvic venous congestion and urinary frequency.

We investigated the mechanisms by which propiverine hydrochloride influenced bladder activity in rats with pelvic venous congestion (PC) and urinary frequency. To create PC rats, female rats were anesthetized with isoflurane and the bilateral common iliac veins and bilateral uterine veins were ligated. At 4 weeks after ligation, we assessed voiding behaviour, locomotor activity, and urinary 8-hydroxydeoxyguanosine (8-OHdG) and nitric oxide metabolites (NOx). We also performed cystometry and measured mRNAs for nitric oxide synthase (NOS) and several receptors in the bladder wall. PC rats showed a decrease in locomotor activity and an increased frequency of urination. There was a decrease in endothelial NOS (eNOS), M3, and TRPV1 mRNA expression in the bladder wall, as well as an increase in inducible NOS (iNOS) mRNA. Administration of propiverine to PC rats increased locomotor activity to the level in sham rats, improved bladder function, decreased urinary 8-OHdG excretion, and increased urinary NOx excretion. In addition, propiverine increased neuronal NOS (nNOS) mRNA expression, and decreased expression of iNOS, M3 and TRPV1 mRNA in the bladder wall. Therefore, propiverine not only improved bladder dysfunction through its previously reported actions (anti-muscarinic effect, Ca antagonist effect, and inhibition of noradrenaline re-uptake), but also by reducing inflammation.

Emotional Stress Facilitates Micturition Reflex: Possible Inhibition by an α1-Adrenoceptor Blocker in the Conscious and Anesthetized State.

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. CONCLUSION: 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.

p-Coumaric Acid Has Protective Effects against Mutant Copper-Zinc Superoxide Dismutase 1 via the Activation of Autophagy in N2a Cells.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective death of motor neurons. In previous our study, an ethanol extract of Brazilian green propolis (EBGP) prevented mutant copper-zinc superoxide dismutase 1 (SOD1mut)-induced neurotoxicity. This paper aims to reveal the effects of p-coumaric acid (p-CA), an active ingredient contained in EBGP, against SOD1mut-induced neurotoxicity. We found that p-CA reduced the accumulation of SOD1mut subcellular aggregation and prevented SOD1mut-associated neurotoxicity. Moreover, p-CA attenuated SOD1mut-induced oxidative stress and endoplasmic reticulum stress, which are significant features in ALS pathology. To examine the mechanism of neuroprotective effects, we focused on autophagy, and we found that p-CA induced autophagy. Additionally, the neuroprotective effects of p-CA were inhibited by chloroquine, an autophagy inhibiter. Therefore, these results obtained in this paper suggest that p-CA prevents SOD1mut-induced neurotoxicity through the activation of autophagy and provides a potential therapeutic approach for ALS.

Identification of reference genes for microRNAs of extracellular vesicles isolated from plasma samples of healthy dogs by ultracentrifugation, precipitation, and membrane affinity chromatography methods.

OBJECTIVE: To compare ultracentrifugation, precipitation, and membrane affinity chromatography methods for isolation of extracellular vesicles (EVs) from canine plasma samples and to identify suitable reference genes for incorporation into a quantitative reverse transcription PCR assay of microRNA expression in plasma EVs of healthy dogs. ANIMALS: 6 healthy Beagles. PROCEDURES: Plasma samples were obtained from each dog, and EVs were isolated from 0.3 mL of these samples via ultracentrifugation, precipitation, and membrane-affinity chromatographic methods. Nanoparticle tracking analysis was performed to determine the concentration and size distribution of EVs isolated by the ultracentrifugation method. Expression levels (cycle threshold values) of 4 microRNAs (let-7a, miR-16, miR-26a, and miR-103) were then compared by means of quantitative reverse transcription PCR assay. Three statistical programs were used to identify the microRNAs most suitable for use as reference genes. RESULTS: Results indicated that ultracentrifugation was the most stable of all 3 methods for isolating microRNAs from 0.3 mL of plasma. Nanoparticle tracking revealed that EV samples obtained by the ultracentrifugation method contained a mean ± SD of approximately 1.59 × 1010 vesicles/mL ± 4.2 × 108 vesicles/mL. Of the 4 microRNAs in plasma EVs isolated by ultracentrifugation, miR-103 was the most stable. CONCLUSIONS AND CLINICAL RELEVANCE: The ultracentrifugation method has potential as a stable method for isolating EVs from canine plasma samples with a high recovery rate, and miR-103 may provide the most stable reference gene for normalizing microRNA expression data pertaining to plasma EVs isolated by ultracentrifugation.

Tadalafil improves bladder dysfunction and object recognition in rats with pelvic venous congestion.

OBJECTIVES: To examine the effects of tadalafil on bladder function and object recognition ability in rats with alterations in urinary frequency and locomotor activity as a result of pelvic venous congestion. METHODS: A total of 48 female rats were divided into three groups (sham, pelvic venous congestion and pelvic venous congestion/tadalafil groups). In the pelvic venous congestion and pelvic venous congestion/tadalafil groups, the bilateral common iliac veins and uterine veins were ligated under anesthesia. Rats in the pelvic venous congestion/tadalafil group received a diet containing tadalafil, and the other rats were fed a normal diet. After 4 weeks, rats underwent analysis of voiding behavior, locomotor activity, a novel object recognition test, continuous cystometry, measurement of plasma monoamines, and measurement of plasma and urinary nitric oxide metabolites. Expression of nitric oxide synthase messenger ribonucleic acid in the bladder wall was also assessed, along with histological examination of the bladder. RESULTS: Rats with pelvic venous congestion showed a higher urinary frequency, lower locomotor activity, and lower plasma and urinary nitric oxide levels than sham rats. The bladder wall endothelial nitric oxide synthase messenger ribonucleic acid level was low and object recognition was impaired. Pelvic venous congestion/tadalafil rats showed improvement in locomotor activity, bladder function and object recognition compared with pelvic venous congestion rats, as well as elevation of plasma and urinary nitric oxide, plasma monoamines, and bladder neuronal nitric oxide synthase messenger ribonucleic acid expression. Bladder wall vascularity was greater in pelvic venous congestion/tadalafil rats compared with sham rats. CONCLUSIONS: In rats with pelvic venous congestion, tadalafil might improve bladder function and the general condition by increasing blood flow to the bladder and brain, and by increasing dopamine levels.

In Vitro Effects of Plasma Collected From Rats Administered Naftopidil on Whole Urinary Bladder Preparation Isolated From Rats.

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). CONCLUSION: 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.

Pelvic venous congestion induces lower urinary tract dysfunction in rats.

Pelvic venous congestion (PC) is thought to be related to several diseases of the lower urinary tract (LUT). We examined the characteristics of the LUT in rats with PC. To create PC, female rats were anesthetized with isoflurane, and the bilateral common iliac veins and bilateral uterine veins were ligated. At 1-8 weeks after either ligation or sham surgery, we performed cystometry with or without administration of carbazochrome sodium sulfonate hydrate or propiverine hydrochloride, histologic examination of the bladder, blood flow imaging, assessment of locomotor activity, measurement of urinary 8-hydroxydeoxyguanosine (8-OHdG) and nitric oxide metabolites (NOx), and the Evans blue dye extravasation test. PC elevated frequency of urination after 2-6 weeks, and caused a decrease of spontaneous locomotor activity. In addition, there was a decrease of bladder blood flow, an increase of bladder vascular permeability, an increase of urinary 8-OHdG, a decrease of urinary NOx, and mild inflammatory changes of the bladder. In rats with PC, frequency of urination was normalized by administration of propiverine or carbazochrome. Rats with PC may be used as a model of PC associated with high frequency of urination, and this model may be useful when developing treatment for LUT symptoms associated with PC.

Effects of gem-dihydroperoxides against mutant copper­zinc superoxide dismutase-mediated neurotoxicity.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by progressive muscle weakness, paralysis, and death. Although its neuropathology is well investigated, currently, effective treatments are unavailable. The mechanism of ALS involves the aggregation and accumulation of several mutant proteins, including mutant copper­zinc superoxide dismutase (SOD1), TAR DNA binding protein 43 kDa (TDP-43) and fused in sarcoma (FUS) proteins. Previous reports have shown that excessive oxidative stress, associated with mitochondrial dysfunction and mutant protein accumulation, contributes to ALS pathology. The present study focuses on the promotion of SOD1 misfolding and aggregation by oxidative stress. Having recently synthesized novel organic gem-dihydroperoxides (DHPs) with high anti-oxidant activity, we now examined whether DHPs reduce the mutant SOD1-induced intracellular aggregates involved in oxidative stress. We found that, among DHPs, 12AC2O significantly inhibited mutant SOD1-induced cell death and reduced the intracellular mutant SOD1 aggregates. Moreover, immunofluorescence staining with redox-sensitive dyes showed that 12AC2O reduced the excessive level of intracellular mutant SOD1-induced reactive oxygen species (ROS). Additionally, ESR analysis showed that 12AC2O exerts a direct scavenging effect against the hydroxyl radical (OH) and the superoxide anion (O2-). These results suggest that 12AC2O is a very useful agent in combination with other agents against ALS.

Factors contributing to salivary human immunodeficiency virus type-1 levels measured by a Poisson distribution-based PCR method.

Objective To elucidate the mechanism underlying secretion of human immunodeficiency virus type 1 (HIV-1) into the oral cavity, by examining the relationships between various oral and systemic factors and the viral load in saliva. Methods Plasma and saliva samples from HIV-1 infected patients were assayed using the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test, version 1.0 and a Poisson distribution-based polymerase chain reaction (PCR) method for quantifying HIV-1 RNA and DNA. Results Forty-four pairs of samples were obtained from 18 patients. Salivary viral load was approximately 10% of the plasma viral load, but higher than the plasma load in two patients. The salivary viral DNA load was < 1% of the total HIV-1 nucleic acid load except in one patient who had more viral DNA than RNA. Multiple regression analysis showed that salivary viral load was significantly correlated with plasma viral load (partial correlation coefficient, 0.90) and the community periodontal index (-0.63). Conclusions The present results suggest that excretion through salivary glands, but not occult bleeding, may be a major pathway of HIV-1 into the oral cavity.

The effects of Brazilian green propolis that contains flavonols against mutant copper-zinc superoxide dismutase-mediated toxicity.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the selective and progressive loss of motor neurons. The purpose of this study was to clarify effects of brazilian green propolis and the active ingredient against ALS-associated mutant copper-zinc superoxide dismutase (SOD1)-mediated toxicity. Ethanol extract of brazilian green propolis (EBGP) protected N2a cells against mutant SOD1-induced neurotoxicity and reduced aggregated mutant SOD1 by induction of autophagy. Kaempferide and kaempferol, the active ingredients of EBGP, also inhibited mutant SOD1-induced cell death and reduced the intracellular mutant SOD1 aggregates. Both kaempferide and kaempferol significantly suppressed mutant SOD1-induced superoxide in mitochondria. Western blot analysis showed that kaempferol potentially induced autophagy via the AMP-activated protein kinase (AMPK) - the mammalian target of rapamycin (mTOR) pathway. These results suggest that EBGP containing the active ingredient against mutant SOD1-mediated toxicity is a promising medicine or health food for prevention and treatment of ALS.

Naftopidil Improves Symptoms in a Rat Model of Tranilast-Induced Interstitial Cystitis.

OBJECTIVE: The effect of naftopidil on symptoms of tranilast-induced interstitial cystitis (IC) was examined in rats. METHODS: Thirty-two female rats were divided into four groups (control, naftopidil, tranilast, and combination groups). Rats in the control group were fed a standard diet, while rats in the naftopidil, tranilast, and combination groups were fed diets containing naftopidil, tranilast, or naftopidil + tranilast, respectively. After 4 weeks of treatment, locomotor activity was measured and continuous cystometry was performed. RESULTS: During the light period, locomotor activity was lower in the tranilast group than in the control, naftopidil, and combination groups. During the dark period, locomotor activity was higher in the naftopidil group than in the other three groups. The combination group showed higher locomotor activity than the tranilast group, but significantly lower activity than the naftopidil group. Continuous cystometry revealed that the interval between bladder contractions was shorter in the tranilast group than in the other three groups. The combination group also had a shorter interval between contractions than the control group. CONCLUSION: Naftopidil improved the symptoms of tranilast-induced IC, such as reduced locomotor activity due to pelvic pain and a shortened interval between bladder contractions. Therefore, naftopidil may be a potential treatment for IC.

Action of naftopidil on spinal serotonergic neurotransmission for inhibition of the micturition reflex in rats.

AIMS: We examined the mechanism of action of naftopidil, an α1D/A blocker, on spinal descending serotonergic neurotransmission for the micturition reflex. METHODS: We examined (1) urinary 5-hydroxyindole acetic acid (5-HIAA) after intraperitoneal administration of saline, para-chlorophenylalanine (PCPA; a serotonin synthetic enzyme inhibitor), and/or 5-hydroxytryptophan (5-HTP; a serotonin precursor); (2) isovolumetric cystometry after intraperitoneal administration of saline, PCPA, and/or 5-HTP and intravenous injection of naftopidil; and (3) isovolumetric cystometry before and after intrathecal administration of serotonin (5-HT) receptor antagonists and intravenous injection of naftopidil. RESULTS: PCPA decreased and 5-HTP increased urinary 5-HIAA/creatinine. Intraperitoneal injection of PCPA did not influence cystometric parameters. Intraperitoneal injection of 5-HTP significantly shortened the interval between bladder contractions. Intravenous injection of naftopidil transiently abolished bladder contractions. However, the duration of abolishment of bladder contractions after injection of naftopidil in rats given PCPA was significantly shorter than that in rats given vehicle, but significantly longer than that in rats given PCPA and 5-HTP. Intrathecal injection of 5-HT1B, 5-HT3, or 5-HT7 receptor antagonists significantly prolonged the interval between bladder contractions. Intrathecal injection of 5-HT1D or 5-HT2B receptor antagonists significantly shortened the interval between bladder contractions. Combined administration of the maximum non-effective dose of 5-HT1D, 5-HT2A, 5-HT2B, 5-HT2C, or 5-HT3 receptor antagonists and intravenous injection of naftopidil significantly shortened the duration of abolishment of bladder contraction compared to intravenous injection of naftopidil alone. CONCLUSIONS: Naftopidil may inhibit the micturition reflex via 5-HT1D, 5-HT2A, 5-HT2B, 5-HT2C, and 5-HT3 receptors in the spinal cord. Neurourol. Urodynam. 36:604-609, 2017. © 2016 Wiley Periodicals, Inc.

Naftopidil improves locomotor activity and urinary frequency in rats with pelvic venous congestion.

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.

Effects of silodosin on bladder activity in rats with frequent urination induced by pelvic venous congestion.

OBJECTIVE: To examine the effects of silodosin on bladder activity using female rats with frequent urination induced by pelvic venous congestion. METHODS: A total of 24 female rats were divided into three groups: sham, pelvic venous congestion and pelvic venous congestion/silodosin group. Rats in the pelvic venous congestion and pelvic venous congestion/silodosin groups were anesthetized with isoflurane, after which the bilateral common iliac veins and uterine veins were ligated. In the pelvic venous congestion/silodosin group, silodosin (0.3 mg/kg/day) was given using an osmotic pump implanted into the subcutaneous space of the back. After 5-6 weeks, analysis of voiding behavior, measurements of urinary 8-hydroxydeoxyguanosine and nitric oxide metabolites, continuous cystometry under urethane anesthesia, and Evans blue dye extravasation test of the bladder were carried out. RESULTS: In comparison with sham rats, pelvic venous congestion rats showed an increase in urination frequency with a concomitant increase in urine volume, a shorter interval between bladder contractions on continuous cystometry, an increase in urinary 8-hydroxydeoxyguanosine, a decrease in urinary nitric oxide metabolites and an increase in vesical vascular permeability. In comparison with pelvic venous congestion rats, pelvic venous congestion/silodosin rats showed a decrease in urination frequency with a concomitant decrease in urine volume, a lower maximum bladder contraction pressure, a longer interval between bladder contractions, an increase in urinary nitric oxide metabolites and a decrease in vascular permeability. CONCLUSION: Silodosin might improve both bladder dysfunction caused by pelvic venous congestion, and the pelvic venous congestion itself.