Role of afferent neurons in stress induced degenerative changes of the bladder

Olvanil activates sensory nerve fibers, increases T cell response and decreases metastasis of breast carcinoma

BACKGROUND

Inactivation of sensory neurons expressing transient receptor potential vanilloid 1 (TRPV1) enhances breast cancer metastasis. Sensory neurons have profound effects on immune response to a wide range of diseases including cancer. Hence, activation of sensory nerves using feasible approaches such as specific TRPV1 agonists may inhibit breast cancer metastasis through neuroimmune pathways. TRPV1 agonists are considered for the treatment of pain and inflammatory diseases.

METHODS

We here first determined the effects of four different TRPV1 agonists on proliferation of three different metastatic breast carcinoma cells since TRPV1 is also expressed in cancer cells. Based on the results obtained under in-vitro conditions, brain metastatic breast carcinoma cells (4TBM) implanted orthotopically into the mammary-pad of Balb-c mice followed by olvanil treatment (i.p.). Changes in tumor growth, metastasis and immune response to cancer cells were determined.

RESULTS

Olvanil dose-dependently activated sensory nerve fibers and markedly suppressed lung and liver metastasis without altering the growth of primary tumors. Olvanil (5 mg/kg) systemically increased T cell count, enhanced intra-tumoral recruitment of CD8+ T cells and increased IFN-γ response to irradiated cancer cells and Con-A. Anti-inflammatory changes such as increased IL-10 and decrease IL-6 as well as S100A8+ cells were observed following olvanil treatment.

CONCLUSIONS

Our results show that anti-metastatic effects of olvanil is mainly due to activation of neuro-immune pathways since olvanil dose used here is not high enough to directly activate immune cells. Furthermore, olvanil effectively depletes sensory neuropeptides; hence, olvanil is a good non-pungent alternative to capsaicin.

Prevalence of childhood trauma and its association with lower urinary tract symptoms in women and men in the LURN study

AIMS

To describe the association between childhood traumas (death of a family member, severe illness, sexual trauma, parental separation) reported by women and men and lower urinary tract symptoms (LUTS).

METHODS

In this secondary analysis of the Lower Urinary Tract Research Network Observational Cohort Study, participants completed the LUTS tool, childhood trauma events scale (CTES), PROMIS depression and anxiety and perceived stress scale. LUTS tool responses were combined to quantify urinary urgency, frequency, incontinence, and overall LUTS severity. Multivariable linear regression tested associations between trauma and LUTS; mental health scores were tested for potential mediation.

RESULTS

In this cohort (n = 1011; 520 women, 491 men), more women reported experiencing at least one trauma (75% vs. 64%, p < .001), greater than three traumas (26% vs. 15%, p < .001), and childhood sexual trauma (23% vs. 7%, p < .001), and reported higher impact from traumatic events compared with men (median [interquartile rnage] CTES score = 10 [5-15] vs. 6 [4-12], p < .001). The number of childhood traumatic events was not associated with severity of overall LUTS (p = .79), urinary frequency (p = .75), urgency (p = .61), or incontinence (p = .21). Childhood sexual trauma was significantly associated with higher incontinence severity (adjusted mean difference 4.5 points, 95% confidence interval= 1.11-7.88, p = .009). Mental health was a mediator between trauma and LUTS among those with at least one childhood trauma.

CONCLUSION

Although total childhood trauma is not associated with LUTS, childhood sexual trauma is associated with urinary incontinence severity. For patients with childhood trauma, half of the effect of CTE Impact score on overall LUTS severity is mediated through the association between trauma and the patient's mental health.

Intrabladder PAC1 Receptor Antagonist, PACAP(6-38), Reduces Urinary Bladder Frequency and Pelvic Sensitivity in Mice Exposed to Repeated Variate Stress (RVS)

Stress causes symptom exacerbation in functional disorders of the urinary bladder. However, the potential mediators and underlying mechanisms of stress effects on micturition reflex function are unknown. We have characterized PACAP (Adcyap1) and PAC1 receptor (Adcyap1r1) signaling in stress-induced urinary bladder dysfunction in mice. We determined PACAP and PAC1 transcripts and protein expressions in the urinary bladder and lumbosacral dorsal root ganglia (DRG) and spinal cord in repeated variate stress (RVS) or control mouse (handling only) groups. RVS in mice significantly (p ≤ 0.01) increased serum corticosterone and urinary bladder NGF content and decreased weight gain. PACAP and PAC1 mRNA and protein were differentially regulated in lower urinary tract tissues with changes observed in lumbosacral DRG and spinal cord but not in urinary bladder. RVS exposure in mice significantly (p ≤ 0.01) increased (2.5-fold) voiding frequency as determined using conscious cystometry. Intrabladder administration of the PAC1 receptor antagonist, PACAP(6-38) (300 nM), significantly (p ≤ 0.01) increased infused volume (1.5-2.7-fold) to elicit a micturition event and increased the intercontraction interval (i.e., decreased voiding frequency) in mice exposed to RVS and in control mice, but changes were smaller in magnitude in control mice. We also evaluated the effect of PAC1 blockade at the level of the urinary bladder on pelvic sensitivity in RVS or control mouse groups using von Frey filament testing. Intrabladder administration of PACAP(6-38) (300 nM) significantly (p ≤ 0.01) reduced pelvic sensitivity following RVS. PACAP/receptor signaling in the CNS and PNS contributes to increased voiding frequency and pelvic sensitivity following RVS and may represent a potential target for therapeutic intervention.

Role of sensory neurons, neuroimmune pathways, and transient receptor potential vanilloid 1 (TRPV1) channels in a murine model of breast cancer metastasis

Sensory nerves sensitive to capsaicin are afferent nerve fibers which contain TRPV1 channels. Activation of these channels induces release of neuropeptides which regulate local blood flow and immune response. Inactivation of sensory neurons either with high-dose capsaicin treatment or local ablation of vagal sensory nerve activity markedly increases metastasis of breast carcinoma formed by 4T1 derivative cells. These cancer cells also induce an extensive systemic inflammatory response. Further findings have documented that lack of local sensory neuromediators alters phenotype of cancer cells within primary tumor leading to overgrowth of metastatic subsets. This might be due to decreases in local and systemic immune response to growing tumor. Specifically, Substance P, one of the most abundant sensory neuropeptides, enhances anti-tumoral immune response evoked by radiotherapy under in vivo conditions. These findings further suggest that activation of TRPV1 channels on sensory neurons may induce an anti-tumoral immune response. We are testing this hypothesis. Our initial results as reported here demonstrate anti-inflammatory consequences of low-dose systemic capsaicin treatment. In conclusion, sensory nerve fibers sensitive to capsaicin have important roles in defense against metastatic breast carcinoma; hence, controlled activation of these neural pathways might be effective in cancer therapy. Specifically, activation of sensory fibers of left vagus nerve using a perineuronal stimulation may inhibit metastasis of breast carcinoma. Likewise, pharmacological modulators of TRPV1 channels may induce anti-tumoral immune response. Exact players of this newly explored defense system are, however, only partly validated, and further studies are required.

The water avoidance stress induces bladder pain due to a prolonged alpha1A adrenoceptor stimulation

Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC) remains an elusive disease with the cause for the pain unclear. BPS/IC patients present increased sympathetic activity and high levels of urinary noradrenaline. At the experimental level, it has been shown that chronic adrenergic stimulation produces pain and bladder changes through an alpha 1A adrenoceptor mediated mechanism. Water avoidance stress (WAS) in rodents reproduces signs of nociception and bladder changes seen in BPS/IC patients. In this study, we explore the possible role of alpha 1A adrenoceptor in bladder pain and morphological changes. WAS was induced in a group of female Wistar rats. A separate WAS group received 0.2 mg/kg day silodosin (WAS + S). Lower abdominal pain was determined by performing sensitivity to Von Frey filaments. Bladder reflex activity was determined by cystometry in anaesthetised animals. Urine was collected for noradrenaline quantification by HPLC. Bladders were harvested and stained with Haematoxylin-eosin (to analyse urothelial morphology and to determine the disruption of surface umbrella cells) or with Toluidine Blue 0.1% to analyse mast cell infiltration. WAS increased urinary noradrenaline level and bladder frequency and decreased mechanical pain threshold, which was reversed by silodosin. WAS induced lymphocytic and mast cells infiltration in the mucosa and mild urothelial disruption, which was absent in WAS + S group. Alpha 1A adrenoceptor stimulation has an important role in the appearance of bladder pain in rats. Since BPS/IC patients present high levels of noradrenaline, alpha 1A stimulation may be an additional trigger for bladder dysfunction presented by these patients. Further studies will determine the clinical relevance of this finding in the treatment of BPS/IC patients.

Urogenital tract disorders in children suspected of being sexually abused

INTRODUCTION

Child sexual abuse (CSA) is generally defined as child exploitation that leads to achievement of sexual satisfaction. According to data from European countries, sexual abuse of children affects 10-40% of girls and 5-20% of boys.

MATERIAL AND METHODS

The Medline, and Web of Science databases were searched with no date limitation on May 2015 using the terms 'child abuse' in conjunction with 'urinary tract', 'urologist', 'urological dysfunction', 'urologic symptoms', 'LUTS' or 'urinary infection'.

RESULTS

Awareness of the CSA problem among paediatricians and urologists is very important, because they are often the only physicians who are able to recognize the problem. CSA diagnosis is possible only through the proper collection of a medical history and a thorough physical examination. Urologists have to remember that children exposed to sexual abuse rarely exhibit abnormal genital findings. In fact, absence of genital findings is the rule rather than the exception. In most cases, the final diagnosis of sexual abuse is based on the child's history and behavior, along with the onset and exacerbation of urologic symptoms.

CONCLUSIONS

In this article, we present a review of studies and literature concerning urinary symptoms in sexually abused children to clarify the problem for a broad group of urologists. We present common symptoms and premises that can point to the right diagnosis and basic guidelines of proceeding after suspicion of abuse.

Sympathetic nervous system and chronic bladder pain: a new tune for an old song

Chronic bladder pain (CBP) patients present with pelvic pain or discomfort during bladder filling, for at least a period of 6 months, which may be accompanied by lower urinary tract symptoms such as frequency, nocturia, and urgency. However, both the etiology of CBP and pathophysiological mechanisms are not well described. A number of clinical and basic animal model findings support involvement of sympathetic nervous system in chronic pain syndromes such as CBP. Examples include sympathetic overactivity and high plasma or urinary catecholamine levels that have a high correlation with nociceptive symptoms. In this review, we explored the current evidence in support of the involvement of sympathetic overactivity in CBP. As bladder inflammation often occurs among subgroups of CBP patients, we discuss the possible role of sympathetic nervous system in mastocytosis as well examples examples of animal models that further support the involvement of sympathetic dysfunction in CBP. As there is substantive evidence for cross-organ sensitization in the pelvis can lead to co-morbidity of genitourinary and gastrointestinal dysfunctions, we also include how sympathetic dysfunction may play a role in a number of co-morbid chronic pain syndromes.

Activation of neuroimmune pathways increases therapeutic effects of radiotherapy on poorly differentiated breast carcinoma

Recent studies document the importance of neuronal dysfunction in cancer development and metastasis. We reported previously that both depletion of neuropeptides in capsaicin-sensitive sensory nerve endings and vagotomy increases metastasis of triple negative breast carcinoma. Of the sensory neuropeptides, Substance P (SP) is distributed widely for regulation of immune functions. We therefore examined the affects of continuous exposure to low doses of SP on brain metastatic cells of the mouse breast carcinoma (4TBM) in the presence of radiotherapy (RT) thought to increase antigenicity of cancer cells. 4TBM cells have a cancer stem cell phenotype and induce extensive visceral metastasis after orthotopic inoculation into the mammary pad. Results demonstrated that SP treatment decreases the number of tumor-infiltrating myeloid-derived suppressor cells as well as the TNF-α response to LPS challenge. SP also increased CD4+Cd25(bright) cells in draining lymph nodes of tumor-bearing animals and IFN-γ secretion from leukocyte culture prepared from lymph nodes and spleens of tumor-bearing animals. SP also prevented tumor-induced degeneration of sensory nerve endings and altered release of angiogenic factors from cancer-associated fibroblasts (CAF) and tumor explants. In accordance with these observed immunological effects, combination treatment of continuous SP with a single dose of RT induced complete tumor regression and significantly reduced or prevented metastasis in 50% of the animals while suppressing primary tumor growth and metastasis in the remaining mice. These original findings demonstrate that SP through neuroimmune modulation can prevent formation of immune suppression in the tumor microenvironment, enhance cytotoxic immunity in the presence of RT and prevent metastatic growth.

Changes in urine levels of substance P, vasoactive intestinal peptide and calcitonin-gene-related peptide in patients with urinary tract infections

Urinary tract infections (UTI) are important health problems and predisposing causes of UTI are not entirely known. Neuro-immune interactions play an important role in human health and disease. Capsaicin-sensitive sensory nerves which in nerve bladder extensively regulate immune system through neuropeptides such as substance P (SP), calcitonin-gene related peptide (CGRP) and vasoactive intestinal peptide (VIP). In addition these neuropeptides also have anti-bacterial effects. To determine how the levels of these peptides changes during UTI, 67 patients (50-90 years-old) diagnosed with UTI in Akdeniz University Faculty of Medicine Hospital were compared with 37 healthy people 50 years or older as the control group. Additionally, 7 patients with UTI symptoms (dysuria, urgency) but with sterile pyuria were also included in the study. Urine samples from 15 patients, whose symptoms regressed with control urine cultures being sterile, were taken after completion of the treatments. Urine neuropeptide levels were determined by ELISA. CGRP levels are significantly higher in patients with UTI, but did not associate with pyuria whereas SP and VIP levels were significantly lower in patients with sterile pyuria, indicating sensory nerve deficiency. Since CGRP exerts immunosuppressive effects, increased levels of the peptide may predispose to UTI. Furthermore, the connection between the observed sensory nerve deficiency and sterile pyuria warrants further studies.

The leukotriene d4 receptor antagonist, montelukast, inhibits mast cell degranulation in the dermis induced by water avoidance stress

Cysteinyl leukotrienes play a part in inflammatory reactions such as asthma and inflammatory bowel diseases. The leukotrienes exert their actions by binding to and activating various receptors. Montelukast, a leukotriene receptor antagonist, which is used in the treatment of asthma has been shown to be effective in inhibiting the action or formation of leukotrienes. Many skin disorders, such as atopic dermatitis and psoriasis, worsen during stress and seem to be related to infiltration and activation of mast cells that are releasing vasoactive and pro-inflammatory mediators. The aim of the present study was to investigate the effects of montelukast on the degranulation of mast cells in the dermis that is induced by water avoidance stress (WAS). Wistar albino rats were divided into four groups of 8 animals each. Control rats were injected with (1) the vehicle solution or (2) the montelukast solution in the absence of WAS. (3) the WAS group of rats was administered vehicle solution following WAS exposure for 2h daily for 5 days. (4) The WAS+ML group was administered montelukast 10mg/kg; i.p. following WAS exposure for 2h daily for 5 days. Dermal mast cell numbers were determined with toluidine blue and tryptase immunohistochemistry and observed using a light microscope. Numbers of both granulated and degranulated mast cells were significantly increased in the WAS group when compared to control rats. Montelukast treatment decreased the number of both mature granulated and degranulated mast cells in rats subjected to WAS. In conclusion, chronic montelukast treatment reduced WAS-induced infiltration and activation of mast cells in the dermis and may provide a useful therapeutic option in stress-induced skin disorders.

Is abuse causally related to urologic symptoms? Results from the Boston Area Community Health (BACH) Survey

OBJECTIVES

We investigated (1) whether sexual, physical, or emotional abuse experienced either as a child or as an adolescent/adult is associated with symptoms of urinary frequency, urgency, and nocturia, and (2) the extent to which the observed association between abuse and urologic symptoms may be causal.

METHODS

Analyses are based on data from the Boston Area Community Health (BACH) survey, a community-based epidemiologic study of many different urologic symptoms and risk factors. BACH used a multistage stratified cluster sample to recruit 5506 adults, aged 30-79 yr (2301 men, 3205 women; 1770 black [African American], 1877 Hispanic, and 1859 white respondents).

RESULTS

The symptoms considered are common, with 33% of BACH respondents reporting urinary frequency, 12% reporting urgency, and 28% reporting nocturia. All three symptoms are positively associated with childhood and adolescent/adult sexual, physical, and emotional abuse (p<0.05), with abuse significantly increasing the odds of urinary frequency by a factor ranging from 1.6 to 1.9, the odds of urgency by a factor from 2.0 to 2.3, and the odds of nocturia by a factor from 1.3 to 1.5.

CONCLUSIONS

Our analyses extend previous work. First, we show a strong association between abuse and urinary frequency, urgency, and nocturia in a community-based random sample. Second, we move beyond discussion of statistical association and find considerable evidence to suggest that the relationship between abuse and these symptoms may be causal.

The Mast Cell in Interstitial Cystitis: Role in Pathophysiology and Pathogenesis

Current evidence from clinical and laboratory studies confirms that mast cells play a central role in the pathogenesis and pathophysiology of interstitial cystitis (IC). In this article, we focus on the role of the mast cell in IC and examine the ways in which mast cells and other pathophysiologic mechanisms are interrelated in this disease. Identifying the patients with IC who have mast cell proliferation and activation will enable us to address this aspect of disease pathophysiology in these individuals with targeted pharmacotherapy to inhibit mast cell activation and mediator release.

Taurine ameliorates stress-induced degeneration of the urinary bladder

We studied the potential effects of taurine, a free radical scavenger, on chronic water avoidance stress (WAS)-induced degeneration of the mucosa of the urinary bladder in experimental rats. Wistar albino rats were exposed to WAS for 2h/day, for 5 days (WAS group). Before exposing them to WAS, taurine (50mg/kg) (WAS+taurine group) was injected intraperitonally into the animals. Samples of urinary bladder were then investigated by light and scanning electron microscopy. Lipid peroxidation and gluthathione levels were also measured in the urinary bladder. In the WAS-only group, inflammatory cell infiltration, increased number of mast cells in the mucosa and ulcerated areas were observed. In the WAS+taurine group, relatively normal urothelial topography with microvilli, moderate inflammatory cell infiltration and decreased numbers of mast cells in the mucosa were observed. The increased lipid peroxidation and decreased glutathione levels in WAS rats were reversed by taurine treatment. We conclude that taurine protects against WAS-induced oxidant urinary bladder injury, and thus may be a possible therapeutic agent against interstitial cystitis, the symptoms of which are aggravated by stress conditions.

An aqueous garlic extract alleviates water avoidance stress-induced degeneration of the urinary bladder

OBJECTIVE

To investigate the role of aqueous garlic extract (AGE) on the water-avoidance stress (WAS)-induced degeneration of the urinary bladder in a rat model.

MATERIALS AND METHODS

Wistar albino rats were exposed to WAS for 2 h/day for 5 days (WAS group), after which, AGE (1 mL/kg) was injected intraperitoneally into the rats (WAS + AGE group). Urinary bladder samples were investigated with both light and scanning electron microscopy, and lipid peroxidation and glutathione levels were also measured in the samples.

RESULTS

In the WAS group there was inflammatory cell infiltration, more mast cells and ulcerated areas in the mucosa. In the WAS + AGE group there was relatively normal urothelial alignment, moderate inflammatory cell infiltration and fewer mast cells in the mucosa. The increased lipid peroxidation and decreased glutathione levels in WAS rats were reversed by AGE treatment.

CONCLUSIONS

These results show that AGE has a protective effect on WAS-induced degenerative changes in the urinary bladder.

Effects of stress and neuropeptides on airway responses in ovalbumin-sensitized rats

OBJECTIVE

The aim of this study was to investigate the influence of stress and neuropeptides on airway responses in ovalbumin (OVA)-sensitized rats.

METHODS

Three experimental conditions were employed: neonatal capsaicin treatment, foot shock stress and OVA sensitization. For neuropeptide depletion, male Wistar rats were neonatally treated with capsaicin (50 mg/kg) or with control solution 2 days after birth. Ninety days later, they were injected with OVA and aluminum hydroxide (ED0) or no injection. Thereafter, rats of the stressed groups were individually placed in a shuttle box where they received 50 mild escapable foot shocks/day; the stressful stimuli were repeated until ED14, when the animals received OVA aerosol. Pulmonary mechanic function was measured before and after OVA challenge in anesthetized and mechanically ventilated rats.

RESULTS

Data on ultrasonic vocalizations and corticosterone showed high levels of anxiety in stressed animals. As expected, a significant increment in airway elastance and resistance after the OVA challenge was found in sensitized rats compared to non-sensitized ones. Capsaicin treatment decreased the values of elastance in sensitized and non-stressed rats; however, after the OVA challenge, elastance was increased in stressed animals. No differences were found in the levels of resistance among sensitized and non-stressed rats; however, a reduced increment in resistance was verified in capsaicin-treated, stressed animals.

CONCLUSIONS

Our results suggest that neurokinin depletion and stress may affect smooth muscle tonus around the airways during an anaphylactic reaction. These data suggest that stress and neuropeptides play a significant role in pulmonary function in OVA-sensitized rats.

A comparative ontogenic study of urinary bladder: impact of the epithelial differentiation in embryonic and newborn rats

The present study aimed to show the cellular and subcellular distribution of glycogen content during the differentiation of urothelial cells from simple cuboidal to stratified transitional epithelium. Bladder samples were taken from rat embryos on the 15th to 19th days and newborn at 21st day. During the development of the bladder, the formation of fusiform vesicles, asymmetric unit membrane (AUM) and microridges were examined with staining with haematoxylin-eosin and periodic acid Schiff for light microscope and periodic acid-thiocharbohydrazide-silver proteinate for transmission electron microscope. The topographical changes of luminal differentiation were examined with the scanning electron microscope. The urothelium was simple cuboidal from 15th till the 17th days of gestation. Glycogen content was present in the cytoplasm till the 18th day of gestation. At the early stage (16th day) of gestation, the apical surface contains microvilli that points the undifferentiated cells. The density of microvilli decreased and ropy microridges appeared at the 17th day of gestation. The small discoid vesicles lined with AUM developed at the apical cytoplasm of the surface cells at the 17th day of gestation. After this stage, both the density of microridges and large and elongated fusiform vesicles increased. The differentiation of the urothelium begins with the formation of the round and small vesicles, continues with the formation of the AUM and at the final stage there is a decrease in both glycogen content and the appearance of the microridges at the luminal surface of the urothelial cells.

Inhibition of substance P activity prevents stress-induced bladder damage

Substance P is a neuropeptide involved in inflammation, immune regulation and stress response. Stress may induce bladder damage by stimulating inflammatory response such as mast cell activation. We here examined the role substance P during stress-induced mast cell degranulation and urothelial injury in rat bladder. Adult Sprague-Dawley rats (200-270 g) were either exposed to cold-immobilization stress or substance P (SP) intracerebroventricularly. Different doses of substance P receptor (NK1R) antagonist CP 99994 were administered peripherally or centrally before the stress exposure. From each group, samples of the bladder were examined with light and electron microscope. Stress- and SP-injected centrally, increased the number of both granulated and degranulated mast cells. Ultrastructurally, urothelial degeneration with vacuolization in the cytoplasm and dilated intercellular spaces were seen. Both central and peripheral injection of CP 99994 prevented stress-induced urothelial degeneration as well as stress-induced mast cell degranulation. In conclusion, centrally and peripherally released substance P is involved in stress-induced bladder damage. Inhibition of NK1R prevents stress-induced pathological changes of urinary bladder and NK1R antagonist can be considered for the treatment of inflammatory bladder diseases.

NK-1 antagonist CP99994 inhibits stress-induced mast cell degranulation in rats

Mast cells are implicated in stress-induced inflammatory skin diseases such as psoriasis. Mechanisms of stress-induced mast cell degranulation however, are not entirely clear. Here we explore the role of activation of a Substance P (SP) receptor (NK-1) on mast cell degranulation upon exposure to stress in rats. A specific nonpeptide NK-1 antagonist, CP99994 was used to treat the rats either peripherally or intracerebroventricularly. Because increased SP activity in the brain may mediate the stress response, we also examined cutaneous mast cell degranulation after central injection of SP. Stress, as well as SP injected centrally, increased mast cell degranulation. Both central and peripheral injection of CP99994 prevented stress-induced mast cell degranulation. Surprisingly, the combination of stress with SP decreased mast cell degranulation, suggesting that high levels of SP may counteract the stress responses. Results in this animal model suggest that NK-1 antagonists may be used therapeutically to treat stress-induced inflammatory skin diseases; however, drug doses should be chosen carefully.

The protective effects of melatonin against water avoidance stress-induced mast cell degranulation in dermis

Nontraumatic psychological water avoidance stress has been shown to induce mucosal degeneration, inflammatory cell infiltration and mast cell degranulation in stomach, ileum, colon and urinary bladder. Many skin disorders, such as atopic dermatitis and psoriasis, worsen during stress and seem to be related with infiltration and activation of mast cells releasing vasoactive and proinflammatory mediators. Melatonin is a free radical scavenger and has cytoprotective effects in inflammatory conditions. The aim of the present study was to investigate the effects of melatonin on water avoidance stress (WAS)-induced degranulation of mast cells in the dermis. Wistar rats were exposed to acute WAS (aWAS group) or chronic WAS (cWAS group). Before exposing to acute WAS, one group of animals was treated with 10mg/kg melatonin (aWAS+mel group). In the cWAS+mel group, treatment with melatonin lasted for 5 days. Dermal mast cells were stained with toluidine blue and investigated using light microscopy. Numbers of mast cells were increased in both aWAS and cWAS groups, but numbers of degranulated mast cells were increased significantly only in the cWAS group when compared to the control group. Numbers of mature granulated and degranulated mast cells were decreased in the cWAS+mel group when compared to the cWAS group. In conclusion, chronic melatonin treatment reduced WAS-induced infiltration and activation of mast cells in dermis and may provide a useful therapeutic option in stress-induced skin disorders.

Volume of Nerve Fibers in the Stress-Induced Bladder of Adult Rats following Capsaicin Treatment

INTRODUCTION

We have investigated the volume of nerve fibers in the rat urinary bladder following systematic exposure to cold-restraint stress and capsaicin treatment.

MATERIALS AND METHODS

Adult Wistar albino rats were either exposed to cold-restraint stress (vehicle group) or treated with capsaicin before exposure to cold-restraint stress (capsaicin group). In the control group, animals were neither exposed to cold-restraint stress nor given capsaicin. From each group, samples of bladder were prepared for morphological investigation and stereological evaluation of the volume of nerve fibers.

RESULTS

Stress exposure was associated with urothelial degeneration, a higher incidence and degranulation of mast cell profiles in the mucosa, and an increased volume of nerve fibers in the muscular layer of the bladder wall. Capsaicin treatment prevented the stress-induced degenerative changes. In the capsaicin group, the volume of nerve fibers in the muscular layer was also significantly smaller than that in the stress group.

CONCLUSIONS

Exposure of adult rats to capsaicin prevented the stress-induced degeneration of the bladder and changed the volume of capsaicin-sensitive fibers in muscular layer. We conclude that capsaicin and related compounds may be useful in treating stress-induced bladder problems.

In vivo models of interstitial cystitis

PURPOSE

We systematically identified and evaluated various animal models that have been studied to help identify the underlying mechanisms of and possible treatment options for interstitial cystitis.

MATERIALS AND METHODS

Models of interstitial cystitis published between 1983 and 2001 were obtained by searching MEDLINE and other Internet databases using cystitis and model as the primary key words. Models with characteristics of interstitial cystitis similar to those defined by National Institutes of Arthritis, Diabetes, Digestive and Kidney Diseases criteria were reviewed. Some articles describing animal models with similar pathological conditions in other organs were also included to enlarge the base of potentially relevant material.

RESULTS

We identified and evaluated some 16 animal models of interstitial cystitis, which we categorized as bladder inflammation induced by intravesical administration of an irritant or immune stimulant, systemic and environmentally induced inflammation, and a naturally occurring model of interstitial cystitis that occurs in cats. Some abnormalities identified in humans and cats with interstitial cystitis can be reproduced in healthy animals using luminal, systemic or environmental stimuli. At the level of the bladder the source of stimulation cannot be discriminated. Variability in the extent of bladder distention complicated the interpretation of some studies. In addition, the noxious stimuli used can affect many epithelial surfaces as well as the urothelium, suggesting they are nonspecific responses to injury rather than specific to interstitial cystitis.

CONCLUSIONS

No model in bladder injury in healthy animals currently reproduces as many features of interstitial cystitis as the naturally occurring disease in cats. While induced models of relative injury may help to provide insight into the bladder response to injury, feline interstitial cystitis follows a similar chronic waxing and waning time course as does interstitial cystitis in humans, which may be more suitable for studying the effects of stressors on the severity of clinical signs as well as newly proposed therapies.