Spinal Cord Injury Causes Marked Tissue Rearrangement in the Urethra-Experimental Study in the Rat.

Traumatic spinal cord injury (SCI) results in the time-dependent development of urinary impairment due to neurogenic detrusor overactivity (NDO) and detrusor-sphincter-dyssynergia (DSD). This is known to be accompanied by massive changes in the bladder wall. It is presently less clear if the urethra wall also undergoes remodelling. To investigate this issue, female rats were submitted to complete spinal transection at the T8/T9 level and left to recover for 1 week and 4 weeks. To confirm the presence of SCI-induced NDO, bladder function was assessed by cystometry under urethane anesthesia before euthanasia. Spinal intact animals were used as controls. Urethras were collected and processed for further analysis. Following thoracic SCI, time-dependent changes in the urethra wall were observed. Histological assessment revealed marked urethral epithelium reorganization in response to SCI, as evidenced by an increase in epithelial thickness. At the muscular layer, SCI resulted in strong atrophy of the smooth muscle present in the urethral sphincter. Innervation was also affected, as evidenced by a pronounced decrease in the expression of markers of general innervation, particularly those present in sensory and sympathetic nerve fibres. The present data show an evident impact of SCI on the urethra, with significant histological rearrangement, accompanied by sensory and sympathetic denervation. It is likely that these changes will affect urethral function and contribute to SCI-induced urinary dysfunction, and they deserve further investigation.

Expression of cleaved SNAP-25 after bladder wall injection of onabotulinumtoxina or abobotulinumtoxina: A comparative study in the mice.

AIMS: To study the expression of cleaved synaptosomal associated protein of 25 kDa (cSNAP-25) in the bladder wall injected with onabotulinumtoxinA (onabotA) or abobotulinumtoxinA (abobotA) and compare the relative potency of these two brands. METHODS: One injection of 0.5 U of onabotA or abobotA diluted in 2 µl of saline was carried out in the bladder dome of adult female mice, whose bladders were exposed by laparotomy. Three days later bladders were collected, divided in five segments (dome, upper, middle and lower body, and trigone) and each one was sectioned and immunoreacted against cSNAP-25, the end product of botulinum toxin type A (BoNT/A) activity. From each of the five segments one section was taken at random and the number of cSNAP-25 immunoreactive (IR) fibers was determined. RESULTS: Each injection resulted in the cleavage of SNAP-25 in all bladder sections, including those of the more distant segment from the injection point. The average number of cSNAP-25 positive fibers was higher in the onabotA, 341 ± 301, than in the abobotA-treated mice, 208 ± 152 (P = 0.003). The number of cSNAP-25 IR fibers varied three to five-fold between animals of each experimental group. CONCLUSIONS: These findings confirm that, when injected in the bladder wall, in the same unit amount and same volume, onabotA is 1.6 times more potent to cleave SNAP-25 than abobotA. The conversion ratio suggested by these experiments is 1:1.6 between onabotA and abobotA. Each injection, although preformed in the same way, may induce substantially different amounts of cSNAP-25. Neurourol. Urodynam. 36:86-90, 2017. © 2015 Wiley Periodicals, Inc.

Spared nerve injury model to study orofacial pain.

BACKGROUND & OBJECTIVES: There are many difficulties in generating and testing orofacial pain in animal models. Thus, only a few and limited models that mimic the human condition are available. The aim of the present research was to develop a new model of trigeminal pain by using a spared nerve injury (SNI) surgical approach in the rat face (SNI-face). METHODS: Under anaesthesia, a small incision was made in the infraorbital region of adult male Wistar rats. Three of the main infraorbital nerve branches were tightly ligated and a 2 mm segment distal to the ligation was resected. Control rats were sham-operated by exposing the nerves. Chemical hyperalgesia was evaluated 15 days after the surgery by analyzing the time spent in face grooming activity and the number of head withdrawals in response to the orofacial formalin test. RESULTS: SNI-face rats presented a significant increase of the formalin-induced pain-related behaviours evaluated both in the acute and tonic phases (expected biphasic pattern), in comparison to sham controls. INTERPRETATION & CONCLUSIONS: The SNI-face model in the rat appears to be a valid approach to evaluate experimental trigeminal pain. Ongoing studies will test the usefulness of this model to evaluate therapeutic strategies for the treatment of orofacial pain.

Effect of onabotulinumtoxinA on intramural parasympathetic ganglia: an experimental study in the guinea pig bladder.

PURPOSE: We investigated whether onabotulinumtoxinA injected in the bladder would affect preganglionic parasympathetic nerve endings in intramural ganglia. MATERIALS AND METHODS: Guinea pig bladders were injected with 5 U of botulinum toxin. At 24 hours bladders were collected and processed for immunohistochemistry using tyrosine hydroxylase, and intact and cleaved SNAP-25. To identify the different populations of affected fibers coursing the ganglia we performed double immunoreactions for cleaved SNAP-25 and VAChT, TH or CGRP. RESULTS: VAChT immunoreactive fibers were identified in axons and varicosities of presynaptic to postganglionic parasympathetic neurons. Those fibers were also immunoreactive to SV2 and SNAP-25. The rare CGRP and TH immunoreactive fibers coursing in the ganglia did not express SV2 or SNAP-25. After onabotulinumtoxinA injection the cleaved form of SNAP-25 was abundantly expressed in parasympathetic fibers. CONCLUSIONS: Botulinum toxin injection in the bladder wall affects preganglionic parasympathetic nerve terminals. This could contribute to the strong effect of botulinum toxin on bladder smooth muscle activity.

Transient receptor potential vanilloid 1 mediates nerve growth factor-induced bladder hyperactivity and noxious input.

OBJECTIVES: To explore the role of transient receptor potential vanilloid 1 (TRPV1) in the excitatory effects of chronic administration of nerve growth factor (NGF) on bladder-generated sensory input and reflex activity. To explore new therapeutic targets for bladder dysfunction. MATERIALS AND METHODS: Wild-type (WT) and TRPV1 knockout (KO) mice received daily intraperitoneal injections of NGF (1 µg/10 g) or saline for a period of 4 days, during which time thermal sensitivity was evaluated daily. On the 5th day, mice were anaesthetized and cystometries were performed. The frequency, amplitude and area under the curve (AUC) of bladder reflex contractions were determined. c-Fos expression was evaluated on L6 spinal cord sections of WT and TRPV1 KO mice treated with saline or chronic NGF by immunohistochemistry. TrkA receptor staining intensity was determined in L6 spinal cord sections and respective dorsal root ganglia of WT and TRPV1 KO mice. RESULTS: Repeated administration of NGF induced thermal hypersensitivity in WT but not in TRPV1 KO mice. The frequency of bladder contractions of saline-treated WT and TRPV1 KO mice was similar, the values respectively being 0.45 ± 0.12/min and 0.46 ± 0.16/min. Treatment with NGF enhanced bladder reflex activity in WT mice to 1.23 ± 0.41/min (P < 0.05). In NGF-treated KO mice, the frequency of bladder contractions was 0.60 ± 0.05/min. Irrespective of treatment, no differences were observed in the amplitude of bladder contractions of WT and TRPV1 KO mice. The AUC was significantly increased in NGF-treated WT-mice, when compared with saline-treated WT-mice. No changes were found in AUC of saline-treated and NGF-treated TRPV1 KO mice. Chronic administration of NGF resulted in a significant increase of spinal c-Fos expression in WT mice (P < 0.05 vs KO animals), but not in TRPV1 KO animals. TrkA expression was similar in WT and TRPV1 KO mice. CONCLUSIONS: NGF-induced bladder overactivity and noxious input depend on the interaction of NGF with TRPV1. The lack of bladder overactivity in TRPV1 KO mice treated with NGF does not represent loss of TrkA expression. TRPV1 is essential for NGF-driven bladder dysfunction and represents a bottleneck target in bladder pathologies associated with NGF up-regulation.

Expression of apoptosis-regulating genes in the rat prostate following botulinum toxin type A injection.

BACKGROUND: Onabotulinumtoxin A (OnabotA) injection has been investigated as a novel treatment for benign prostatic enlargement caused by benign prostatic hyperplasia. An OnabotA-induced volume reduction caused by sympathetic fibers impairment has been proposed as a potential mechanism of action. Our aim was to investigate the expression of apoptosis-regulating proteins in the rat prostate following OnabotA intraprostatic injection. METHODS: Adult Wistar rats were injected in the ventral lobes of the prostate with 10 U of OnabotA or saline. A set of OnabotA-injected animals was further treated with 0.5 mg/kg of phenylephrine (PHE) subcutaneously daily. All animals were sacrificed after 1 week and had their prostates harvested. Immunohistochemical staining was performed for Bax, Bcl-xL and caspase-3 proteins and visualized by the avidin-biotin method. The optical density of the glandular cells was also determined, with measurement of differences between average optical densities for each group. RESULTS: Saline-treated animals showed intense epithelial staining for Bcl-xL and a faint labelling for both Bax and Caspase-3. OnabotA-treated rats showed a reduced epithelial staining of Bcl-xL and a consistently increased Bax and Caspase-3 staining when compared with saline-treated animals. PHE-treated animals showed a stronger Bcl-xL staining and reduced staining of both Bax and Caspase-3 when compared to the OnabotA group. Mean signal intensity measurements for each immunoreaction confirmed a significant decrease of the signal intensity for Bcl-xL and a significant increase of the signal intensity for Bax and Caspase 3 in OnabotA-injected animals when compared with the control group. In OnabotA+PHE treated animals mean signal intensity for Bcl-xL, Bax and Caspase 3 immunoreactions was identical to that of the control animals. CONCLUSIONS: These results support the hypothesis that OnabotA activates apoptotic pathways in the rat prostate through a mechanism that involves sympathetic outflow impairment.

DU Is Induced by Low Levels of Urinary ATP in a Rat Model of Partial Bladder Outlet Obstruction: The Incidence of Both Events Decreases after Deobstruction.

Objectives: To investigate, in initial phases of bladder outlet obstruction (BOO), the urinary ATP levels, the incidence of detrusor underactivity (DU), and if they change after deobstruction. Methods: Adult female Wistar rats submitted to partial BOO (pBOO) and sham-obstruction were used. Cystometry was performed 3 or 15 days after pBOO and fluid was collected from the urethra for ATP determination. Bladders were harvested for morphological evaluation of the urothelium. DU was defined as the average of voiding contractions (VC) of sham-operated animals, with 3 SD at 15 days after the sham surgery. In another group of animals in which pBOO was relieved at 15 days and bladders were let to recover for 15 days, the incidence of DU and ATP levels were also accessed. The Kruskal-Wallis test was followed by Dunn's multiple comparisons test, and Spearman's correlation test was used. Results: DU was present in 13% and 67% of the bladders at 3 and 15 days after pBOO, respectively, and in 20% of the bladders at 15 days after deobstruction. ATP levels were significantly lower in DU/pBOO versus sham and non-DU/pBOO rats. A strong positive correlation between ATP levels and VC/min was obtained (r = 0.63). DU bladders had extensive areas in which umbrella cells appeared stretched, the width exceeding that presented by sham animals. Conclusions: Low urothelial ATP parallels with a high incidence of DU early after pBOO.

VEGF signaling mediates bladder neuroplasticity and inflammation in response to BCG.

BACKGROUND: This work tests the hypothesis that increased levels of vascular endothelial growth factor (VEGF) observed during bladder inflammation modulates nerve plasticity. METHODS: Chronic inflammation was induced by intravesical instillations of Bacillus Calmette-Guérin (BCG) into the urinary bladder and the density of nerves expressing the transient receptor potential vanilloid subfamily 1 (TRPV1) or pan-neuronal marker PGP9.5 was used to quantify alterations in peripheral nerve plasticity. Some mice were treated with B20, a VEGF neutralizing antibody to reduce the participation of VEGF. Additional mice were treated systemically with antibodies engineered to specifically block the binding of VEGF to NRP1 (anti-NRP1B) and NRP2 (NRP2B), or the binding of semaphorins to NRP1 (anti-NRP1 A) to diminish activity of axon guidance molecules such as neuropilins (NRPs) and semaphorins (SEMAs). To confirm that VEGF is capable of inducing inflammation and neuronal plasticity, another group of mice was instilled with recombinant VEGF165 or VEGF121 into the urinary bladder. RESULTS: The major finding of this work was that chronic BCG instillation resulted in inflammation and an overwhelming increase in both PGP9.5 and TRPV1 immunoreactivity, primarily in the sub-urothelium of the urinary bladder. Treatment of mice with anti-VEGF neutralizing antibody (B20) abolished the effect of BCG on inflammation and nerve density.NRP1A and NRP1B antibodies, known to reduce BCG-induced inflammation, failed to block BCG-induced increase in nerve fibers. However, the NRP2B antibody dramatically potentiated the effects of BCG in increasing PGP9.5-, TRPV1-, substance P (SP)-, and calcitonin gene-related peptide (CGRP)-immunoreactivity (IR). Finally, instillation of VEGF121 or VEGF165 into the mouse bladder recapitulated the effects of BCG and resulted in a significant inflammation and increase in nerve density. CONCLUSIONS: For the first time, evidence is being presented supporting that chronic BCG instillation into the mouse bladder promotes a significant increase in peripheral nerve density that was mimicked by VEGF instillation. Effects of BCG were abolished by pre-treatment with neutralizing VEGF antibody. The present results implicate the VEGF pathway as a key modulator of inflammation and nerve plasticity, introduces a new animal model for investigation of VEGF-induced nerve plasticity, and suggests putative mechanisms underlying this phenomenon.

Modulation of urinary bladder innervation: TRPV1 and botulinum toxin A.

The persisting interest around neurotoxins such as vanilloids and botulinum toxin (BoNT) derives from their marked effect on detrusor overactivity refractory to conventional antimuscarinic treatments. In addition, both are administered by intravesical route. This offers three potential advantages. First, intravesical therapy is an easy way to provide high concentrations of pharmacological agents in the bladder tissue without causing unsuitable levels in other organs. Second, drugs effective on the bladder, but inappropriate for systemic administration, can be safely used as it is the case of vanilloids and BoNT. Third, the effects of one single treatment might be extremely longlasting, contributing to render these therapies highly attractive to patients despite the fact that the reasons to the prolonged effect are still incompletely understood. Attractive as it may be, intravesical pharmacological therapy should still be considered as a second-line treatment in patients refractory to conventional oral antimuscarinic therapy or who do not tolerate its systemic side effects. However, the increasing off-label use of these neurotoxins justifies a reappraisal of their pharmacological properties.

N-acyldopamines control striatal input terminals via novel ligand-gated cation channels.

Endogenous analogues of capsaicin, N-acyldopamines, were previously identified from striatal extracts, but the putative presynaptic role of their receptor, the TRPV(1)R (formerly: vanilloid or capsaicin receptor) in the caudate-putamen is unclear. We found that the endogenous TRPV(1)R agonists, N-arachidonoyldopamine (NADA) and oleoyldopamine (OLDA) with EC(50) values in the nanomolar range, as well as the synthetic TRPV(1)R activator 2-aminoethoxydiphenylborane (2APB), and palmytoyldopamine (PALDA, another endogenous N-acyldopamine inactive at the TRPV(1)R), but not capsaicin or other endogenous and synthetic cannabinoids, triggered a rapid Ca(2+) entry with the concomitant stimulation of glutamate and dopamine release. These effects persisted in the TRPV(1)R null-mutant mice, and were insensitive to antagonists of common ionotropic receptors, to several TRPV(1)R antagonists and to the absence of K(+). Furthermore, these N-acyldopamine receptors in glutamatergic and dopaminergic terminals are different based on their different sensitivity to anandamide, capsazepine and Gd(3+) at nanomolar concentrations. Altogether, novel ion channels instead of the TRPV(1)R mediate the presynaptic action of N-acyldopamines in the striatum of adult rodents.

GRC-6211, a new oral specific TRPV1 antagonist, decreases bladder overactivity and noxious bladder input in cystitis animal models.

PURPOSE: We evaluated the effects of GRC-6211, an orally active TRPV1 antagonist, on the function and noxious input of naïve and inflamed bladders. MATERIALS AND METHODS: In urethane (Sigma(R)) anesthetized rats 0.5 ml GRC-6211 (0.001, 0.01, 0.1 and 1 mg/kg weight) or its vehicle (0.5% methylcellulose) were administered through a duodenal catheter and cystometry was done during infusion of saline, 100 microM capsaicin or 0.5% acetic acid (Merck, Feltham, United Kingdom). Cystometry was also performed in WT and TRPV1 knockout mice treated with 1 mg/kg GRC-6211. Cystometry was done in rats inflamed with lipopolysaccharide after receiving 0.1 mg/kg GRC-6221 or vehicle. Spinal c-fos expression induced by 0.5% acetic acid was investigated after 0.1 mg/kg GRC-6211 or vehicle administration. TRPV1 immunoreactivity was evaluated in the bladder after GRC-6211 administration. RESULTS: The reflex activity of rat and WT mice naïve bladders was unchanged by GRC-6211 up to a dose of 0.1 mg/kg. At 1 mg/kg contractions were transiently suppressed in naïve rats and WT mice but not in TRPV1 knockout mice. GRC-6211 (0.1 mg/kg) completely prevented capsaicin induced irritation, while the 0.001, 0.01 or 0.1 mg/kg dose decreased the mean +/- SD frequency of bladder contractions during acetic acid infusion from 1.5 +/- 0.3 to 1.35 +/- 0.35 (not significant), 0.9 +/- 0.2 (p <0.05) and 0.8 +/- 0.2 (p <0.05), respectively. Lipopolysaccharide inflamed rats had 1.4 +/- 0.4 and 0.8 +/- 0.1 contractions per minute after vehicle and GRC-6211, respectively (p <0.05). The c-fos expression induced by acetic acid was decreased by GRC-6211 (85.5 +/- 19.1 to 46.7 +/- 9.4, p <0.05). GRC-6211 did not change bladder TRPV1 immunoreactivity. CONCLUSIONS: GRC-6211 counteracts the bladder hyperactivity and noxious input induced by cystitis. At high doses it suppresses normal bladder activity by a TRPV1 dependent mechanism. TRPV1 antagonists might be useful for cystitis.

Functional transient receptor potential vanilloid 1 is expressed in human urothelial cells.

PURPOSE: We investigated the expression and functional status of TRPV1 receptor in human urothelial cells. MATERIAL AND METHODS: Human urothelium was cultured and TRPV1 receptor expression was studied by immunocytochemistry and reverse transcriptase-polymerase chain reaction. The influence of inflammatory mediators on TRPV1 mRNA levels was also studied. Functional assays (cobalt uptake measurements and whole cell voltage clamp records) were used to study the response of urothelial cells to capsaicin, temperature, low pH and inflammatory mediators. Capsaicin induced adenosine triphosphate release from urothelial cells was assessed by bioluminescence. RESULTS: TRPV1 protein and mRNA were detected in human urothelial cells and mRNA more than tripled in the presence of inflammatory mediators. Nerve growth factor treatment alone did not affect TRPV1 mRNA expression. Capsaicin (100 nM and 1 microM) and heat (41C and 45C) evoked cobalt uptake and inflammatory mediators lowered the temperature threshold for TRPV1 activation to 37C. Capsaicin (1 microM) induced TRPV1 desensitization to further applications of the agonist. In whole cell patch clamp experiments 1 microM capsaicin and a heat ramp from 37C to 50C caused inward currents. The same concentration of capsaicin induced the release of about 7 fmol adenosine triphosphate per mg. CONCLUSIONS: TRPV1 receptors expressed by human urothelial cells respond to capsaicin and thermal stimuli. Capsaicin evoked release of adenosine triphosphate suggests that human urothelial TRPV1 is involved in the afferent branch of the micturition reflex. Inflammatory mediators decrease the TRPV1 thermal threshold of activation to body temperature and increase its expression. This finding may be relevant for symptoms associated with cystitis.

Neurochemical characterization of insulin receptor-expressing primary sensory neurons in wild-type and vanilloid type 1 transient receptor potential receptor knockout mice.

The insulin receptor (IR) is expressed by a subpopulation of primary sensory neurons (PSN), including a proportion of cells expressing the nociceptive transducer vanilloid type 1 transient receptor potential receptor (TRPV1). Recent data suggest functional links between the IR and other receptors, including TRPV1, which could be involved in the development of PSN malfunctions in pathological insulin secretion. Here we used combined immunohistochemical labelling on sections from L4-5 dorsal root ganglia of wild-type (WT) and TRPV1 knockout (KO) mice to examine the neurochemical properties of IR-expressing PSN and the possible effect of deletion of TRPV1 on those characteristics. We found that antibodies raised against the high-molecular-weight neurofilament (NF-200) and the neurofilament protein peripherin distinguished between small and large neurons. We also found that the IR was expressed predominantly by the small peripherin-immunopositive cells both in the WT and in the KO animals. IR expression, however, did not show any preference between the major subpopulations of the small cells, the calcitonin gene-related peptide (CGRP)-expressing and Bandeiraea simplicifolia isolectin B4 (IB4)-binding neurons, either in the WT or in the KO mice. Nevertheless, a significant proportion of the IR-expressing cells also expressed TRPV1. Comparison of the staining pattern of these markers showed no difference between WT and KO animals. These findings indicate that the majority of the IR-expressing PSN are small neurons, which are considered as nociceptive cells. Furthermore, these data show that deletion of the TRPV1 gene does not induce any additional changes in neurochemical phenotype of nociceptive PSN.

Bladder sensory desensitization decreases urinary urgency.

BACKGROUND: Bladder desensitization has been investigated as an alternative treatment for refractory detrusor overactivity. Most open and controlled clinical trials conducted with intravesical RTX showed that desensitization delays the appearance of involuntary detrusor contractions during bladder filling and decreases the number of episodes of urgency incontinence. Urgency is being recognised as the fundamental symptom of overactive bladder (OAB), a symptomatic complex which recent epidemiological studies have shown to affect more than 10% of the Western population. As anti-muscarinic drugs, the first line treatment for OAB, are far from being able to fully control urgency, the opportunity to test other therapeutic approaches is created. The present work was, therefore, designed as an exploratory investigation to evaluate the effect of bladder desensitization on urinary urgency. METHODS: Twenty-three OAB patients with refractory urgency entered, after given informed consent, a 30 days run-in period in which medications influencing the bladder function were interrupted. At the end of this period patients filled a seven-day voiding chart where they scored, using a 0-4 scale, the bladder sensations felt before each voiding. Then, patients were instilled with 100 ml of 10% ethanol in saline (vehicle solution) and 30 days later a second seven-day voiding chart was collected. Finally, patients were instilled with 100 ml of 50 nM RTX in 10% ethanol in saline. At 1 and 3 months additional voiding charts were collected. At the end of the vehicle and 3 months period patients were asked to give their subjective impression about the outcome of the treatment and about the willingness to repeat the previous instillation. RESULTS: At the end of the run-in period the mean number of episodes of urgency per week was 71 +/- 12 (mean +/- SEM). After vehicle instillation, the mean number of episodes of urgency was 56 +/- 11, but only 4 patients (17%) considered that their urinary condition had improved enough to repeat the treatment. At 1 and 3 months after RTX the number of episodes of urgency decreased to 39 +/- 9 (p = 0.002) and 37 +/- 6 (p = 0.02), respectively (p indicates statistical differences against vehicle). The percentage of patients with subjective improvement after RTX and willing to repeat the instillation at a later occasion was 69%. CONCLUSION: In OAB patients with refractory urgency bladder desensitization should be further investigated as an alternative to the standard management. Additionally, the specific effect of RTX on TRPV1 receptors suggests that urothelium and sub-urothelial C-fibers play an important role to the generation of urgency sensation.

Inflammation of peripheral tissues and injury to peripheral nerves induce differing effects in the expression of the calcium-sensitive N-arachydonoylethanolamine-synthesizing enzyme and related molecules in rat primary sensory neurons.

Elevation of intracellular Ca2+ concentration induces the synthesis of N-arachydonoylethanolamine (anandamide) in a subpopulation of primary sensory neurons. N-acylphosphatidylethanolamine phospholipase D (NAPE-PLD) is the only known enzyme that synthesizes anandamide in a Ca2+ -dependent manner. NAPE-PLD mRNA as well as anandamide's main targets, the excitatory transient receptor potential vanilloid type 1 ion channel (TRPV1), the inhibitory cannabinoid type 1 (CB1) receptor, and the main anandamide-hydrolyzing enzyme fatty acid amide hydrolase (FAAH), are all expressed by subpopulations of nociceptive primary sensory neurons. Thus, NAPE-PLD, TRPV1, the CB1 receptor, and FAAH could form an autocrine signaling system that could shape the activity of a major subpopulation of nociceptive primary sensory neurons, contributing to the development of pain. Although the expression patterns of TRPV1, the CB1 receptor, and FAAH have been comprehensively elucidated, little is known about NAPE-PLD expression in primary sensory neurons under physiological and pathological conditions. This study shows that NAPE-PLD is expressed by about one-third of primary sensory neurons, the overwhelming majority of which also express nociceptive markers as well as the CB1 receptor, TRPV1, and FAAH. Inflammation of peripheral tissues and injury to peripheral nerves induce differing but concerted changes in the expression pattern of NAPE-PLD, the CB1 receptor, TRPV1, and FAAH. Together these data indicate the existence of the anatomical basis for an autocrine signaling system in a major proportion of nociceptive primary sensory neurons and that alterations in that autocrine signaling by peripheral pathologies could contribute to the development of both inflammatory and neuropathic pain.

TRPV1 (vanilloid receptor) in the urinary tract: expression, function and clinical applications.

The transient receptor potential vanilloid subfamily 1 (TRPV1) is an ion channel activated by capsaicin, heat, protons and endogenous ligands such as anandamide. It is largely expressed in the urinary tract of mammals. Structures in which the receptor expression is firmly established include sensory fibers and urothelial cells, although the presence of TRPV1 in other cell types has been reported. As in other systems, pain perception was the first role attributed to TRPV1 in the urinary tract. However, it is now increasingly clear that TRPV1 also regulates the frequency of bladder reflex contractions, either through direct excitation of sensory fibers or through urothelial-sensory fiber cross talk involving the release of neuromediators from the epithelial cells. In addition, the recent identification of the receptor in urothelial and prostatic cancer cells raise the exciting hypothesis that TRPV1 is involved in cell differentiation. Desensitization of the receptor by capsaicin and resiniferatoxin has been investigated for therapeutic purposes. For the moment, lower urinary tract dysfunctions in which some benefit was obtained include painful bladder syndrome and overactive bladder of neurogenic and non-neurogenic origin. However, desensitization may become obsolete when non-toxic, potent TRPV1 antagonists become available.

Anandamide-evoked activation of vanilloid receptor 1 contributes to the development of bladder hyperreflexia and nociceptive transmission to spinal dorsal horn neurons in cystitis.

The role of anandamide in the development of inflammatory hyperalgesia and visceral hyperreflexia was studied in the rat urinary bladder. Animals were given intraperitoneal cyclophosphamide injection, which evokes painful hemorrhagic cystitis accompanied by increased bladder reflex activity. The vanilloid receptor 1 [transient receptor potential vanilloid 1 (TRPV1)] antagonist capsazepine, applied onto the serosal surface of bladders, significantly reduced the hyperreflexia. Mass spectrometric analysis revealed that cyclophosphamide injection significantly and persistently increased the anandamide content of bladder tissues. The increase in the anandamide content paralleled the development of reflex hyperactivity. Anandamide (1-100 microm), applied onto the serosal surface of naive bladders, increased the reflex activity in a concentration-dependent manner. Repeated anandamide applications did not produce desensitization of the response. The anandamide-evoked effect was blocked by capsazepine or by instillation of resiniferatoxin, the ultrapotent TRPV1 agonist, into the bladders 24 hr before the anandamide challenge. The cannabinoid 1 receptor antagonist SR141716A [N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide] significantly increased the potency of anandamide in enhancing bladder reflex activity in naive but not in cyclophosphamide-injected animals. Application of the fatty acid amide hydrolyze inhibitor palmitoylisopropylamine onto the serosal surface of bladders also increased the reflex activity both in naive and cyclophosphamide-injected rats. This latter effect in naive animals was blocked by capsazepine and by resiniferatoxin pretreatment. Finally, intravesical instillation of anandamide (50 microm) increased c-fos expression in the spinal cord, which was reduced by capsazepine or by resiniferatoxin pretreatment. These results suggest that anandamide, through activating TRPV1, contributes to the development of hyperreflexia and hyperalgesia during cystitis.

A importância da informação científica na educação para a prevenção de doenças infecciosas virais / The importance of scientific information in education for the prevention of viral infectocontagious diseases / La importancia de la información científica en la educación para la prevención de enfermedades infecciosas virales

Objetivo: orientar alunos do ensino fundamental e médio do CED07-Ceilândia / DF sobre a importância das práticas de higiene em prol da prevenção de doenças infecciosas. Método: o estudo foi desenhado em três fases distintas: aplicação de questionários de higiene pessoal; palestras e workshops práticos sobre patologias humanas; e avaliação do projeto pelos alunos participantes. Resultados: Os resultados mostram que 57% dos alunos compartilham objetos pessoais, um número muito elevado, uma vez que a literatura aponta que existem várias patologias que podem ser adquiridas de objetos individuais. Observou-se também que os alunos não têm o hábito de tirar os sapatos antes de entrar em suas casas. Eles alegaram desconhecer os riscos de contaminação por esse comportamento, mas afirmaram que, após as informações fornecidas pelo projeto, estariam mais atentos a esse fator de contaminação domiciliar. Assim, acredita-se que as práticas educativas e informativas sobre o tema proposto foram relevantes, uma vez que os alunos relataram que aprenderam com as atividades desenvolvidas e estavam dispostos a mudar seu comportamento em relação às práticas de higiene. Conclusão: O estudo também demonstra que tais práticas contribuem para a prevenção de doenças por meio de medidas simples, como a melhoria da higiene pessoal, essencial para a saúde pública, uma vez que muitas doenças graves podem ter reduzido o índice de contaminação apenas com orientações educativas. e práticas de higiene corretas.

Objective: to guide students of elementary and high-school levels at CED07-Ceilândia/DF on the importance of hygiene practices in favor of preventing against infectious diseases. Method: the study was designed in three distinct phases: application of questionnaires about personal hygiene; lectures and practical workshops on human pathologies; and evaluation of the project by participating students. Results: The results show that 57% of the students share personal items, a considerably high number since the literature points out that there are several pathologies that can be acquired using individual objects. It was also noted that students are not in the habit of removing their shoes before entering their homes. They claimed that they were unaware of the risks of contamination through this behavior, but stated that, after the information provided by the project, they would be more attentive to this home contamination factor. Thus, it is believed that the educational and informational practices on the proposed theme were relevant, as students reported that they learned from the developed activities and were willing to change their behavior regarding hygiene practices. Conclusion: The study also demonstrates that such practices contribute to disease prevention through simple measures, such as better personal hygiene, which is essential for public health, since many serious diseases can have reduced contamination rate only with educational guidelines and correct hygiene practices.

Objetivo: orientar a los estudiantes de primaria y secundaria del CED07-Ceilândia / DF sobre la importancia de las prácticas de higiene a favor de la prevención de enfermedades infecciosas. Método: el estudio se diseñó en tres fases diferenciadas: aplicación de cuestionarios de higiene personal; conferencias y talleres prácticos sobre patologías humanas; y evaluación del proyecto por parte de los estudiantes participantes. Resultados: Los resultados muestran que el 57% de los estudiantes comparten objetos personales, un número muy alto, ya que la literatura señala que existen varias patologías que se pueden adquirir a partir de objetos individuales. También se observó que los estudiantes no tienen la costumbre de quitarse los zapatos antes de ingresar a sus hogares. Afirmaron desconocer los riesgos de contaminación por este comportamiento, pero manifestaron que, luego de la información brindada por el proyecto, estarían más atentos a este factor de contaminación domiciliaria. Así, se cree que las prácticas educativas e informativas sobre el tema propuesto fueron relevantes, ya que los estudiantes informaron que aprendieron de las actividades desarrolladas y estaban dispuestos a cambiar su comportamiento en relación a las prácticas de higiene. Conclusión: El estudio también demuestra que dichas prácticas contribuyen a la prevención de enfermedades a través de medidas simples, como la mejora de la higiene personal, fundamental para la salud pública, ya que muchas enfermedades graves pueden haber reducido la tasa de contaminación solo con pautas educativas. y prácticas de higiene correctas.

Desensitization follows excitation of bladder primary afferents by intravesical capsaicin, as shown by c-fos activation in the rat spinal cord.

Activation of the protooncogene c-fos at spinal cord segments T12-L2 and L5-S1 was used to study the effects of topical administration of capsaicin on bladder primary afferents coursing in the hypogastric (HGN) or pelvic (PN) nerves of adult rats. Two hours after capsaicin instillation in the bladder numerous Fos cells occurred in lamina I at T12-L2 and in lamina I, intermediolateral gray matter (ILG) and dorsal commissure (DCM) at L5-S1. Twenty-four hours later, the Fos immunoreaction had disappeared from the spinal cord. At this time, instillation of 1% acetic acid into the bladder of capsaicin-treated rats induced considerably fewer Fos cells than in animals that had been instilled only with the vehicle solution for capsaicin. The difference in the average number of Fos cells was statistically significant in lamina I, ILG and DCM at L5-S1 but not in lamina I at T12-L2. Thus, intravesical capsaicin at the doses used excites bladder primary afferents coursing in the HGN and PN, but only desensitizes those coursing in the PN. It is suggested that this may depend on the differential occurrence of capsaicin receptors in the two nerves.

Nerve growth factor regulates galanin and c-jun overexpression occurring in dorsal root ganglion cells after intravesical resiniferatoxin application.

Galanin and c-jun expression after a single bladder instillation of resiniferatoxin was studied by immunocytochemistry in L6 dorsal root ganglia (DRG) neurons of the rat. The role of nerve growth factor depletion in causing that effect was also investigated. Three days after instillation of a 100 nM resiniferatoxin solution a marked increase in the number of galanin and c-Jun immunoreactive DRG cells was evident bilaterally. The increments were still present at 8 days and disappeared 1 month after treatment. Systemic administration of nerve growth factor, 100 microg/kg, prevented both overexpressions. Results suggest that the changes induced in bladder sensory neurons by intravesical resiniferatoxin are due, at least in part, to the temporary deprivation of bladder-derived neurotrophic factors, namely nerve growth factor, in those neurons.