Involvement of Purinergic Neurotransmission in Ketamine Induced Bladder Dysfunction

The Role of Intravenous Anesthetics for Neuro: Protection or Toxicity?

The primary intravenous anesthetics employed in clinical practice encompass dexmedetomidine (Dex), propofol, ketamine, etomidate, midazolam, and remimazolam. Apart from their established sedative, analgesic, and anxiolytic properties, an increasing body of research has uncovered neuroprotective effects of intravenous anesthetics in various animal and cellular models, as well as in clinical studies. However, there also exists conflicting evidence pointing to the potential neurotoxic effects of these intravenous anesthetics. The role of intravenous anesthetics for neuro on both sides of protection or toxicity has been rarely summarized. Considering the mentioned above, this work aims to offer a comprehensive understanding of the underlying mechanisms involved both in the central nerve system (CNS) and the peripheral nerve system (PNS) and provide valuable insights into the potential safety and risk associated with the clinical use of intravenous anesthetics.

Newer therapies and surgical management of ketamine-induced uropathy: A review

BACKGROUND AND AIMS

Ketamine use as a recreational drug is becoming more popular nowadays. Ketamine-induced uropathy (KIU) is a late finding observed with long-term use of ketamine. A systematic review of Ketamine-Induced Uropathy was performed to emphasise its key clinical manifestations, mechanism of action and establish an effective treatment pathway.

METHODS AND RESULTS

A literature search was conducted in MEDLINE via Pubmed and Cochrane using the keywords ketamine and bladder, ketamine and uropathy, and ketamine and epidemiology. The search strategy was limited to articles published from 2000 to 2023. Both animal and human studies were included. A total of 101 papers were reviewed based on topic relevance from the title and abstracts available. While ketamine is a controlled drug in the United Kingdom (UK) and other countries, 283 ketamine-related deaths have been reported in the UK. There is no definite pathogenesis but multiple potential mechanisms that cause KIU and its related symptoms. KIU involves chronic inflammation of the bladder, ureteral wall thickening, hydronephrosis and finally, chronic renal failure. A multidisciplinary approach is paramount when managing these patients to break the vicious cycle. The mainstay of medical and surgical treatment pathways is continued abstinence to prevent symptom relapse. This review included the pathophysiology, novel medical treatments and surgical management of KIU.

CONCLUSION

KIU is a rare but significantly disabling condition often seen among ketamine abusers. With the rising trend in drug addiction, KIU is expected to be more common. Unfortunately, it is a late complication in chronic ketamine abusers and is only partially reversible even with abstinence. This review discusses this rare entity's newer medical treatments and surgical options.

Pathophysiology, clinical presentation, and management of ketamine-induced cystitis

Ketamine is illegally used as a recreational drug in many Asian countries. Long-term ketamine abusers often develop irritable bladder symptoms that gradually develop into more severe urinary frequency and urgency and eventually into a painful ulcerated bladder. These patients typically have reduced functional bladder capacity, increased bladder sensation, detrusor overactivity, severe urgency, urinary incontinence, and bladder contracture. Ketamine metabolites can cause severe inflammation of the urothelium, urothelial barrier deficits, vascular endothelial fibrinoid changes, increased oxidative stress, and bladder wall fibrosis. A decrease in bladder compliance, urinary tract infection, severe bladder pain with a full bladder, and painful micturition are also common symptoms. Finally, with continued abuse of ketamine, hydronephrosis, ureteral stricture, vesicoureteral reflux, and renal failure may develop. Cessation of ketamine is the mainstay of treatment. Lower urinary tract symptoms usually relapse if patients reuse ketamine after stopping. In cases of severe ketamine cystitis, only augmentation enterocystoplasty can relieve bladder pain and restore normal lower urinary tract function. This article reviews the underlying pathophysiology, clinical characteristics, and management of ketamine cystitis.

Curcumin alleviates ketamine-induced oxidative stress and apoptosis via Nrf2 signaling pathway in rats' cerebral cortex and hippocampus

AIMS

To investigate curcumin's protective effect on nerve damage caused by ketamine anesthesia via the Nrf2 signaling pathway. Rats and PC12 cells were used in this experiment to investigate the mechanism of nerve injury caused by ketamine anesthesia. Furthermore, our findings suggest that curcumin may affect oxidative stress and apoptosis by targeting the Nrf2 pathway, thereby alleviating the nerve injury caused by ketamine.

METHODS

The rat cerebral cortex and hippocampus were stained with Nissl and immunohistochemistry to determine the number of neurons and the expression of Caspase-3, Bcl-2, and Bax. CCK-8 assay was used to determine the optimal concentration of ketamine, curcumin, and H₂ O₂ in PC12 cells. Flow cytometry was used to detect changes in reactive oxygen species and the rate of apoptosis in each group. To determine whether Nrf2 entered the nucleus, immunofluorescence was used. Both tissues and cells were subjected to RT-PCR and Western blotting detection at the same time. The levels of oxidative stress were determined using a malondialdehyde (MDA) and superoxide dismutase (SOD) assay kit.

RESULTS

Ketamine reduced the number of neurons in the cortex and hippocampus of rats. The proteins Bax and Caspase-3 were upregulated, while Bcl-2 was down-regulated in the cortex and hippocampus. The viability of PC12 cells has decreased. MDA content increased while SOD activity decreased in cortex, hippocampus, and PC12 cells. Ketamine had an effect on the expression of some genes in the Nrf2 signaling pathway as well as apoptosis. Curcumin pretreatment may be able to prevent ketamine-induced damage.

CONCLUSIONS

The oxidative stress and apoptosis caused by ketamine during growth of the cerebral cortex, hippocampus, and PC12 cells may be decreased by curcumin's activation of the Nrf2 signaling pathway. Our research provides a potential strategy for the secure administration of anesthetics in medical settings.

Ketamine Inhalation Alters Behavior and Lower Urinary Tract Function in Mice

We aimed to evaluate behavioral and lower urinary tract changes in mice using a novel ketamine inhalation model mimicking human ketamine abusers and compare the results to those obtained using a ketamine intraperitoneal injection model. C57BL/6N mice were placed in a transparent acrylic observation cage connected to an ultrasonic nebulizer producing ketamine (KI) or saline (SI) fog. The mice were given KI or SI fog twice a week for three months. In another experiment arm, the mice were given intraperitoneal ketamine injections (KP) or saline injections (SP) twice a week for three months. The presence of urine ketamine (>100 ng/mL) was determined using a quick test kit. Locomotor activity was recorded by video using the open field test. Lower urinary tract function was assessed using urine spots, cystometry and histology. KI and KP mice crossed the center more frequently and traveled farther than SI and SP mice. Only KI mice, however, demonstrated popcorn-like jumping, and frequent center crossing. Detrusor overactivity, reduced cystometric bladder capacity, and denuded mucosa were observed in both KI and KP mice. Ketamine inhalation induces behavioral and lower urinary tract changes in mice that are comparable to intraperitoneal ketamine injections.

Ketamine plus Alcohol: What We Know and What We Can Expect about This

Drug abuse has become a public health concern. The misuse of ketamine, a psychedelic substance, has increased worldwide. In addition, the co-abuse with alcohol is frequently identified among misusers. Considering that ketamine and alcohol share several pharmacological targets, we hypothesize that the consumption of both psychoactive substances may synergically intensify the toxicological consequences, both under the effect of drugs available in body systems and during withdrawal. The aim of this review is to examine the toxicological mechanisms related to ketamine plus ethanol co-abuse, as well the consequences on cardiorespiratory, digestive, urinary, and central nervous systems. Furthermore, we provide a comprehensive discussion about the probable sites of shared molecular mechanisms that may elicit additional hazardous effects. Finally, we highlight the gaps of knowledge in this area, which deserves further research.

Therapeutic Effect of Platelet-Rich Plasma Improves Bladder Overactivity in the Pathogenesis of Ketamine-Induced Ulcerative Cystitis in a Rat Model

The present study attempted to elucidate whether intravesical instillation of platelet-rich plasma (PRP) could decrease bladder inflammation and ameliorate bladder hyperactivity in ketamine ulcerative cystitis (KIC) rat model. Female Sprague Dawley (S-D) rats were randomly divided into control group, ketamine-treated group, ketamine with PRP treated group, and ketamine with platelet-poor plasma (PPP) treated group. Cystometry and micturition frequency/volume studies were performed to investigate bladder function. The morphological change of bladder was investigated by Mason’s trichrome staining. Western blotting analysis were carried out to examine the protein expressions of inflammation, urothelial differentiation, proliferation, urothelial barrier function, angiogenesis and neurogenesis related proteins. The results revealed that treatment with ketamine significantly deteriorated bladder capacity, decreased voiding function and enhanced bladder overactivity. These pathological damage and interstitial fibrosis may via NF-κB/COX-2 signaling pathways and muscarinic receptor overexpression. PRP treatment decreased inflammatory fibrotic biosynthesis, attenuated oxidative stress, promoted urothelial cell regeneration, and enhanced angiogenesis and neurogenesis, thereafter recovered bladder dysfunction and ameliorate the bladder hyperactivity in KIC rat model. These findings suggested that the PRP therapy may offer new treatment options for those clinical KIC patients.

Molecular Pathophysiology and Potential Therapeutic Strategies of Ketamine-Related Cystitis

Ketamine was first synthesized as a clinical medicine for anesthesia in 1970. It has been used as a recreational drug because of its low cost and hallucination effect in the past decade. Part of ketamine abusers may experience ketamine-related cystitis (KC) and suffer from lower urinary tract symptoms, including urinary frequency, urgency, and severe bladder pain. As the disease progression, a contracted bladder, petechial hemorrhage of the bladder mucosa, and ureteral stricture with hydronephrosis may occur. The pathophysiology of KC is still uncertain, although several hypotheses have been raised. Cessation of ketamine abuse is critical for the management of KC to prevent progressive disease, and effective treatment has not been established. Research has provided some theoretical bases for developing in vitro experiments, animal models, and clinical trials. This review summarized evidence of molecular mechanisms of KC and potential treatment strategies for KC. Further basic and clinical studies will help us better understand the mechanism and develop an effective treatment for KC.

A Novel Intravesical Dextrose Injection Improves Lower Urinary Tract Symptoms on Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a painful recurrent condition characterized by the discomfort of the bladder, and current treatment options have limited effectiveness. Prolotherapy is a well-known treatment that involves the injection of non-biologic solutions to reduce pain and/or promote proliferation of soft tissue, and dextrose is the most common injectate. This study investigated the effects of dextrose prolotherapy in a rat model of IC/BPS and patients with IC/BPS. We used cyclophosphamide to induce IC/BPS in rats, and intravesical instillation of 10% dextrose solution was performed. After 1 week, we conducted a urodynamic test, bladder staining, and ECM-related gene expression analysis to examine the treatment’s efficacy. We found that dextrose treatment could recover the instability of the bladder, reduce frequent urination, and improve the glycosaminoglycan layer regeneration and the bladder wall thickness along with a significant intense expression of CD44 receptors. Furthermore, we enrolled 29 IC/BPS patients with previous hyaluronic acid/Botox treatment for more than 6 months with remained unchanged condition. In this study, they received intravesical injections of 10% dextrose solution followed by assessments for up to 12 weeks. Patient characteristics and a 3-day voiding diary before treatment were recorded. Patient responses were examined using IC/BPS-related questionnaires. Moreover, expressions of growth factors and cytokines were analyzed. The results demonstrated that dextrose prolotherapy in patients with IC/BPS reduced the frequency of treatment over time, with the mean number of treatments being 3.03 ± 1.52, and significantly reduced the incidence of nocturia and questionnaire scores associated with symptoms. Dextrose prolotherapy significantly enhanced EGF level and, in contrast, reduced the level of HGF, PIGF-1, and VEGF-D after several weeks following treatment. The cytokine analysis showed that the expressions of IL-12p70 and IL-10 were significantly up-regulated after dextrose prolotherapy in IC/BPS patients. The levels of most growth factors and cytokines in IC/BPS patients had no significant difference and showed a similar tendency as time progressed when compared to healthy controls. Overall, the alteration of growth factors and cytokines exhibited safe treatment and potential stimulation of tissue remodeling. In summary, our study demonstrated that dextrose prolotherapy is a promising treatment strategy for IC/BPS disease management.

Ketamine-New Possibilities in the Treatment of Depression: A Narrative Review

The SARS-CoV-2 coronavirus epidemic has led to an increase in the number of people with depression. Symptoms related to the mental sphere (mainly depression and anxiety) may be experienced by one third of the worldwide population. This entails the need for the effective and rapid treatment of depressive episodes. An effective drug seems to be s-ketamine, which was accepted in March 2019 by the Food and Drug Administration (FDA) for the treatment of drug-resistant depression. This drug provides a quick antidepressant effect with maximum effectiveness achieved after 24 h. It also appears to reduce the occurrence of suicidal thoughts. However, research into undesirable effects, especially in groups of people susceptible to psychotic episodes or those who use alcohol or psychoactive substances, is necessary.

Ketamine enhances autophagy and endoplasmic reticulum stress in rats and SV-HUC-1 cells via activating IRE1-TRAF2-ASK1-JNK pathway

Background Ketamine-related cystitis (KC) has been researched in many clinical studies, but its exact mechanism is ambiguous and needs further research. Methods We established a KC rat model and analyzed physiological, biochemical, and urodynamic parameters of ketamine (KET)-related bladder injury. Bladder histologic feature, reactive oxygen species (ROS), autophagy-, apoptosis-, and endoplasmic reticulum stress (ERS)-related markers were examined by hematoxylin and eosin staining, Masson staining, ROS kit, quantitative real-time polymerase chain reaction, and western blot. In vitro, effects of 0.01, 0.1, and 1 mM KET on cell vitality, apoptosis, ROS level, autophagy-, apoptosis-, and ERS-related markers were examined again. Effects of KET-1 and salubrinal on complex formation, autophagy-, apoptosis-, and ERS-related markers were examined by Co-Immunoprecipitation and western blot. After transfection with shIRE1, complex formation, cell biological behaviors, ROS level, autophagy-, apoptosis-, and ERS-related markers were examined again. Results KET induced bladder hyperactivity and injury. KET facilitated urinary frequency, ROS production, and induced bladder histologic injury by activating autophagy-, apoptosis-, and ERS-related markers in rats. In vitro, KET (0.01, 0.1, and 1 mM) restrained cell vitality and elevated apoptosis and ROS level via activating autophagy-, apoptosis-, and ERS-related markers. Moreover, salubrinal reversed the promotion of KET-1 on complex formation, autophagy-, apoptosis-, and ERS-related marker expressions. After transfection with shIRE1, shIRE1 weakened complex formation induced by KET-1, and the effects of KET-1 on cells were offset by shIRE1. Conclusion KET enhanced autophagy and ERS in vivo and in vitro via restraining IRE1-TRAF2-ASK1-JNK pathway.

Rodent models of ketamine-induced cystitis

AIMS

Long-term or recreational use of ketamine affects the urinary system and can result in ketamine-induced cystitis (KIC). Rodent models of KIC are important to study KIC pathophysiology and are paramount to the future development of therapies for this painful condition. This review aims to provide a summary of rodent models of KIC, focusing on disease induction, experimental methods, and pathological features of the model.

METHOD

A literature search was performed using the National Center for Biotechnology Information (NCBI) Pubmed database up to March 2021. 20 articles met the inclusion criteria and were finally selected.

RESULTS

There are considerable variations in the rodent models used for studying KIC in terms of the strain of the animal being used; dose, duration, and route of ketamine administration to induce KIC, and assessment of pathological features.

CONCLUSION

KIC remains difficult to fully recapitulate in humans. Improved characterization of KIC models and the experimental parameters and meticulous discussion on translational limitations are required to improve the translational value of research using rodent models of KIC.

Molecular pathways underlying tissue injuries in the bladder with ketamine cystitis

Ketamine cystitis (KC) is a chronic bladder inflammation leading to urinary urgency, frequency, and pain. The pathogenesis of KC is complicated and involves multiple tissue injuries in the bladder. Recent studies indicated that urothelium disruption, lamina propria fibrosis and inflammation, microvascular injury, neuropathological alterations, and bladder smooth muscle (BSM) abnormalities all contribute to the pathogenesis of KC. Ketamine has been shown to induce these tissue injuries by regulating different signaling pathways. Ketamine can stimulate antiproliferative factor, adenosine triphosphate, and oxidative stress to disrupt urothelium. Lamina propria fibrosis and inflammation are associated with the activation of cyclooxygenase-2, nitric oxide synthase, immunoglobulin E, and transforming growth factor β1. Ketamine contributes to microvascular injury via the N-methyl-D aspartic receptor (NMDAR), and multiple inflammatory and angiogenic factors such as tumor necrosis factor α and vascular endothelial growth factor. For BSM abnormalities, ketamine can depress the protein kinase B, extracellular signal-regulated kinase, Cav1.2, and muscarinic receptor signaling. Elevated purinergic signaling also plays a role in BSM abnormalities. In addition, ketamine affects neuropathological alterations in the bladder by regulating NMDAR- and brain-derived neurotrophic factor-dependent signaling. Inflammatory cells also contribute to neuropathological changes via the secretion of chemical mediators. Clarifying the role and function of these signaling underlying tissue injuries in the bladder with KC can contribute to a better understanding of the pathophysiology of this disease and to the design of effective treatments for KC.

Purinergic signalling in the urinary bladder - When function becomes dysfunction

Knowledge of the participation of ATP and related purines in urinary tract physiology has been established over the last five decades through the work of many independent groups, inspired by, and building on the pioneering studies of Professor Geoffrey Burnstock and his coworkers. As part of a series of reviews in this tribute edition, the present article summarises our current understanding of purines and purinergic signalling in modulating and regulating urinary tract function. Purinergic mechanisms underlying the origin of bladder pain; sensations of bladder filling and urinary tract motility; and regulation of detrusor smooth muscle contraction are described, encompassing the relevant history of discovery and consolidation of knowledge as methodologies and pharmacological tools have developed. We consider normal physiology, including development and ageing and then move to pathophysiology, discussing the causal and consequential contribution of purinergic signalling mechanism and their constituent components (receptors, signal transduction, effector molecules) to bladder dysfunction.

Smaller bladder capacity and stronger bladder contractility in patients with ketamine cystitis are associated with elevated TRPV1 and TRPV4

Stronger contractility and smaller bladder capacity are common symptoms in ketamine cystitis (KC). This study investigates the association between expression levels of transient receptor potential cation channel subfamily V (TRPV) proteins and the clinical characteristics of KC. Bladder tissues were obtained from 24 patients with KC and four asymptomatic control subjects. Video urodynamic parameters were obtained before surgical procedures. The TRPV proteins were investigated by immunoblotting, immunofluorescence staining, and immunohistochemistry. The Pearson test was used to associate the expression levels of TRPV proteins with clinical characteristics of KC. The expression level of TRPV1 and TRPV4 was significantly higher in the severe KC bladders than in mild KC or control bladders. The TRPV1 proteins were localized in all urothelial cell layers, and TRPV4 was located in the basal cells and lamina propria. The expression of TRPV1 was negatively associated with maximal bladder capacity (r = − 0.66, P = 0.01). The expression of TRPV4 was positively associated with the velocity of detrusor pressure rise to the maximum flow rate (r = 0.53, P = 0.01). These observations suggest smaller bladder capacity and stronger contractility in KC are associated with an elevated expression of TRPV1 and TRPV4, respectively.

Is medicinal ketamine associated with urinary dysfunction issues? Assessment of both the European Medicines Agency (EMA) and the UK Yellow Card Scheme pharmacovigilance database-related reports

OBJECTIVE

A range of ketamine-induced uropathy (KIU) issues have been typically described in ketamine misusers. Conversely, more knowledge is needed in terms of medicinal ketamine-related urological disturbances, since ketamine prescribing is being increasingly considered for a range of medical and psychopathological conditions.

METHODS

To assess medicinal KIU issues, we aimed at analyzing both the 2005-2017 European Medicines Agency (EMA) and the 2006-2018 UK Yellow Card Scheme (YCS) pharmacovigilance databases.

RESULTS

A total number (eg, all categories) of 11 632 EMA ketamine-related adverse drug reaction (ADR) reports were here identified. Out of these, some 9971 ADRs (eg, 85.7% of the total) were judged as "suspect" and were here analyzed. Some 1758 ADRs (17.7% of 9971, corresponding to 194 individual patients) referred to urological issues, relating to either kidney/ureter (922 ADRs) or bladder/urethra (837 ADRs). Ketamine was the sole drug administered in 156/194 (80.4%) cases/patients. Although most cases occurred in the 1 month-1 year time frame following the start of ketamine prescribing, in 30 cases the ADR occurred within 48 hours. Most ADR-related cases resolved, although both sequelae (18 cases) and fatalities (79/1758; 4.5%) were recorded. Overall, YCS data were consistent with EMA findings, with some 50/217 (23%) ADRs referring to renal/urinary disorders.

CONCLUSIONS

Current data may only represent a gross underestimate of the KIU real prevalence issues. It is here suggested that chronic treatment involving higher doses/repeated exposure to ketamine be restricted to the context of controlled trials or clinical audits.

Ketamine induces endoplasmic reticulum stress in rats and SV-HUC-1 human uroepithelial cells by activating NLRP3/TXNIP aix

Many clinical studies have been conducted on ketamine-associated cystitis. However, the underlying mechanisms of ketamine-associated cystitis still remain unclear. Bladder tissues of rats were stained by Hematoxylin and Eosin (HE). The viability of human uroepithelial cells (SV-HUC-1 cells) was determined by cell counting kit-8 (CCK-8). Apoptosis and reactive oxygen species (ROS) were examined by flow cytometry. Additionally, the expressions of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β and IL-18 were respectively determined by reverse transcription quantitative (RTq)-PCR and enzyme-linked immunosorbent assay (ELISA). The mRNA and protein levels of B-cell lymphoma/leukemia-2 (Bcl2), Bcl-2-associated X protein (Bax), cleaved caspase 3, glucose-regulated protein 78 (GRP78), CCAAT/enhancer binding protein homologous protein (CHOP), NOD-like receptor 3 (NLRP3), thioredoxin-interacting protein (TXNIP), Catalase and MnSOD were examined by RT-qPCR and Western blot. Small interfering RNA target TXNIP transfection was performed using Lipofectamine™ 2000. We found that ketamine effectively damaged bladder tissues of rats and promoted apoptosis through regulating the expression levels of GRP78, CHOP, Bcl-2, Bax and cleaved Caspase-3 proteins in vivo and in vitro. NLRP3 inflammatory body and TXNIP were activated by ketamine, which was supported by the changes in TNF-α, IL-6, IL-1 and IL-18 in vivo and in vitro. Furthermore, knocking down TXNIP reversed the effects of ketamine on apoptosis and NLRP3 inflammatory body in SV-HUC-1 cells. Meanwhile, the changes of Catalase and MnSOD showed that ROS was enhanced by ketamine, however, such an effect was ameliorated by down-regulation of TXNIP in SV-HUC-1 cells. Ketamine promoted cell apoptosis and induced inflammation in vivo and in vitro by regulating NLRP3/TXNIP aix.

What urologists need to know about ketamine-induced uropathy: A systematic review

AIMS

Ketamine is a general anesthetic. Dissociative effects and low cost led ketamine becoming an illegal recreational drug in young adults. Ketamine-induced uropathy (KIU) is one of the complications observed in abusers. This study aimed to provide a systematic literature review on KIU clinical presentation, pathophysiology, and treatments.

METHODS

We performed the literature search in PubMed, Web of Science, Scopus, and Embase using the terms ketamine and bladder. English papers on human and animal studies were accepted.

RESULTS

A total of 75 papers were selected. Regular ketamine users complain about severe storage symptoms and pelvic pain. Hydronephrosis may develop in long-term abusers and is correlated to the contracted bladder, ureteral stenosis, or vesicoureteral reflux due to ureteral involvement and/or bladder fibrosis. Cystoscopy shows ulcerative cystitis. Ketamine in urine might exert direct toxicity to the urothelium, disrupting its barrier function and enhancing cell apoptosis. The presence of ketamine/ions in the bladder wall result in neurogenic/IgE-mediated inflammation, stimulation of the inducible nitric oxide synthase-cytokines-cyclooxygenase pathway with persistent inflammation and fibrosis. Abstinence is the first therapeutic step. Anti-inflammatory drugs, analgesics and anticholinergics, intravesical instillation of hyaluronic acid, hydrodistension and intravesical injection of botulin toxin-A were helpful in patients with early-stage KIU. In patients with end-stage disease, the control of intractable symptoms and the increase of bladder capacity were the main recommendations to perform augmentation enterocystoplasty.

CONCLUSIONS

KIU is becoming a worldwide health concern, which should be taken into account in the differential diagnosis of ulcerative cystitis.

Intraperitoneal injection of ketamine enhances apoptosis in urothelium via autophagy in rats

Ketamine abusing is associated with ulcerative cystitis, but the mechanisms remain unclear. This study aimed to investigate the existence of ketamine-induced symptom in a rat model and evaluate the underlining mechanisms. Sprague-Dawley rats were chosen and randomly divided into 12 groups (n = 8), such as the control group, low dose of ketamine (10 mg/kg/day), middle dose of ketamine (30 mg/kg/day) and high dose of ketamine (50 mg/kg/day) groups. The experimental groups were administrated ketamine i.p. daily, whereas the control groups were administrated with saline. After 1, 3, and 6 months of treatment, the bladder tissues were collected. Haematoxylin and eosin (HE) staining and a transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay were used to evaluate the bladder epithelium pathology and urothelial apoptosis, respectively. The protein expression levels of LC3, p62, Beclin1 were assessed by Western blotting. HE staining results of the experimental rats showed the bladder tissue denudation of the urothelial epithelium with edema and congestion compared with the control groups. TUNEL staining showed a significantly higher number of apoptotic cells in experimental groups than in the control groups. The protein LC3 and Beclin1 had significantly higher levels compared with control groups. The protein p62 had lower levels compared with control groups. The expression levels correlated with contraction of ketamine and treatment time. HE staining, TUNEL staining and Western blot results showed dose-dependent, time-dependent autophage in ketamine-treated rats. All the results suggested that autophagy proteins might be involved in inflammatory response in rats.

Ketamine‑induced bladder dysfunction is associated with extracellular matrix accumulation and impairment of calcium signaling in a mouse model

Due to the rising abuse of ketamine usage in recent years, ketamine-induced urinary tract syndrome has received increasing attention. The present study aimed to investigate the molecular mechanism underlying ketamine-associated cystitis in a mouse model. Female C57BL/6 mice were randomly divided into two groups: One group was treated with ketamine (100 mg/kg/day of ketamine for 20 weeks), whereas, the control group was treated with saline solution. In each group, micturition frequency and urine volume were examined to assess urinary voiding functions. Mouse bladders were extracted and samples were examined for pathological and morphological alterations using hematoxylin and eosin staining, Masson's trichrome staining and scanning electron microscopy. A cDNA microarray was conducted to investigate the differentially expressed genes following treatment with ketamine. The results suggested that bladder hyperactivity increased in the mice treated with ketamine. Furthermore, treatment with ketamine resulted in a smooth apical epithelial surface, subepithelial vascular congestion and lymphoplasmacytic aggregation. Microarray analysis identified a number of genes involved in extracellular matrix accumulation, which is associated with connective tissue fibrosis progression, and in calcium signaling regulation, that was associated with urinary bladder smooth muscle contraction. Collectively, the present results suggested that these differentially expressed genes may serve critical roles in ketamine-induced alterations of micturition patterns and urothelial pathogenesis. Furthermore, the present findings may provide a theoretical basis for the development of effective therapies to treat ketamine-induced urinary tract syndrome.

Early life voiding dysfunction leads to lower urinary tract dysfunction through alteration of muscarinic and purinergic signaling in the bladder

Lower urinary tract dysfunction (LUTD) is a common problem in children and constitutes up to 40% of pediatric urology clinic visits. Improved diagnosis and interventions have been leading to better outcomes in many patients, whereas some children are left untreated or do not respond to the treatment successfully. In addition, many of these patients are lost by the pediatric urologists during their teenage years, and the outcome in later life largely remains unidentified. Studies suggest childhood LUTD is associated with subsequent adult urinary tract symptoms. However, whether and how early life LUTD attributes to urinary symptoms in those patients later in life remains to be elucidated. In the current study, we investigated the effects of early life voiding perturbation on bladder function using a neonatal maternal separation (NMS) protocol in mice. The NMS group displayed a delayed development of voluntary voiding behavior, a significant reduction of functional bladder capacity, and bladder overactivity compared with control mice later in life. In vitro evaluation of detrusor smooth muscle and molecular study showed a decrease in muscarinic contribution alongside an increase in purinergic contribution in detrusor contractility in NMS mice compared with control group. These results suggest that early life bladder dysfunction interfered with the normal maturation of the voluntary micturition control and facilitated LUTD in a later stage, which is at least partly attributed to an alteration of muscarinic and purinergic signaling in the urinary bladder.

Potential Orphan Drug Therapy of Intravesical Liposomal Onabotulinumtoxin-A for Ketamine-Induced Cystitis by Mucosal Protection and Anti-inflammation in a Rat Model

Ketamine abusers may develop ulcerative cystitis and severe lower urinary tract symptoms, which is a medical dilemma. Recently, researchers have found the endemic of ketamine-induced cystitis worldwide. The intravesical administration of liposome-encapsulated onabotulinumtoxinA (Lipotoxin) might facilitate the healing of the damaged urothelium from liposomes, and reduce the urinary symptoms by onabotulinumtoxinA-induced chemo-denervation. Using female Sprague-Dawley rats, we investigated the effects of Lipotoxin on ketamine-induced cystitis. Functional magnetic resonance imaging, metabolic cage study, and cystometry were conducted. Paraffin-embedded sections were stained. The bladder mucosa and muscle proteins were assessed through Western blotting. We observed that repeated intravesical Lipotoxin instillation could improve suburothelial hemorrhage, recover the urothelial tight junction and adhesion proteins (zonula occludens-1 and E-cadherin), ensure less substance P in the urothelium, inhibit the overexpression of inflammatory mediators (IL-6, TNF-α, nuclear NF-κB, and COX-2) in the detrusor, suppress the upregulation of the mucosal TRPV1 and detrusor M₂-mAChR, and ameliorate bladder overactivity in the ketamine-treated rats. These data reveal the mechanisms underlying the action of Lipotoxin in ketamine-induced cystitis of rats, which provide a basis of Lipotoxin for further treating ketamine-induced cystitis in humans.

Changes to the bladder epithelial barrier are associated with ketamine-induced cystitis

The aim of the present study was to investigate the changes of the bladder epithelial barrier in the pathogenesis of ketamine-induced cystitis (KIC). A total of 60 female mice were randomly allocated into control and ketamine groups, which received daily intraperitoneal injections of saline and ketamine, respectively. Micturition behavior was recorded in 2-h intervals at the end of 4, 8 and 12 weeks, and bladders were harvested for subsequent analyses. Routine hematoxylin and eosin staining was performed on the bladders and histopathological changes were analyzed using light microscopy. The distribution of zonula occludens-1 (ZO-1) protein was determined by immunohistochemical analysis. The ultrastructure of umbrella cells was observed using a transmission electron microscope (TEM). Ketamine-addicted mice exhibited a significantly increased frequency of micturitions following 8 and 12 weeks of ketamine treatment (P<0.05 and P<0.01, respectively). Suburothelial congestion and infiltration of mononuclear cells was observed in ketamine-addicted mice following 8 and 12 weeks of treatment. Immunohistochemical examination demonstrated that there was an increased abnormal distribution of ZO-1 in the bladders of ketamine-treated mice compared with control mice. TEM analysis demonstrated that the surface of bladder urothelium became flattened, the tight junctions between umbrella cells became thinner and the endothelial cells exhibited cell body shrinkage, chromatin condensation and layer denudation in mice treated with ketamine. The present study indicated that the structural and functional changes to the bladder epithelial barrier caused by long-term use of ketamine may be key mechanisms in the development of KIC.

The putative involvement of actin-binding proteins and cytoskeleton proteins in pathological mechanisms of ketamine cystitis-Revealed by a prospective pilot study using proteomic approaches

PURPOSE

Ketamine-induced cystitis (KC) among chronic ketamine young abusers has increased dramatically and it has brought attention for Urologists. The underlying pathophysiological mechanism(s) of KC is still unclear. Therefore, the purpose of this study is to elucidate the possible pathophysiological mechanism(s) of KC through proteomic techniques.

EXPERIMENTAL DESIGN

Bladder tissues are obtained from seven patients with KC, seven patients with interstitial cystitis/bladder pain syndrome, and five control subjects who underwent video-urodynamic study followed by augmentation enterocystoplasty to increase bladder capacity. 2DE/MS/MS-based approach, functional classifications, and network analyses are used for proteomic and bioinformatics analyses and protein validation is carried out by Western blot analysis.

RESULTS

Among the proteins identified, bioinformatics analyses revealed that several actin binding related proteins such as cofilin-1, myosin light polypeptide 9, filamin A, gelsolin, lamin A are involved in the apoptosis. Besides, the contractile proteins and cytoskeleton proteins such as myosin light polypeptide 9, filamin A, and calponin are found downregulated in KC bladders.

CONCLUSIONS AND CLINICAL RELEVANCE

Increased apoptosis in KC might be mediated by actin-binding proteins and a Ca²⁺ -activated protease. Rapid detrusor contraction in KC might be induced by contractile proteins and cytoskeleton proteins.

Abnormal Sensory Protein Expression and Urothelial Dysfunction in Ketamine-Related Cystitis in Humans

Purpose

The aim of this study was to analyze patterns of sensory protein expression and urothelial dysfunction in ketamine-related cystitis (KC) in humans.

Methods

Biopsies of bladder mucosa were performed in 29 KC patients during cystoscopy. Then specimens were analyzed for tryptase, zonula occludens-1 (ZO-1), E-cadherin, and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) with immunofluorescence staining and quantification. In addition, 10 healthy control bladder specimens were analyzed and compared with the KC specimens. Another 16 whole bladder specimens obtained from partial cystectomy were also analyzed for the muscarinic receptors M2 and M3, endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), β-3 adrenergic receptors (β3-ARs), and the P2X₃ receptor by western blotting. In addition, 3 normal control bladder specimens were analyzed and compared with the KC specimens.

Results

The KC bladder mucosa revealed significantly less expression of ZO-1 and E-cadherin, and greater expression of TUNEL and tryptase activity than the control samples. The expression of M3 and β3-AR in the KC specimens was significantly greater than in the controls. The expression of iNOS, eNOS, M2, and P2X₃ was not significantly different between the KC and control specimens.

Conclusions

The bladder tissue of KC patients revealed significant urothelial dysfunction, which was associated with mast-cell mediated inflammation, increased urothelial cell apoptosis, and increased expression of the M3 and β3-AR.

Evaluation of urinary bladder fibrogenesis in a mouse model of long-term ketamine injection

Long-term ketamine abuse has been shown to affect the lower urinary tract and result in interstitial cystitis-like syndrome. However, the causative mechanism of ketamine-induced dysfunction remains unclear. The present study aimed to investigate the physiological, histological and molecular changes on ketamine-associated cystitis (KC) in a mouse model. Both male and female Balb/c mice were separately distributed into the control group (normal saline) and ketamine group, which received ketamine hydrochloride (100 mg/kg/day) daily by intraperitoneal injection for a total period of 20 weeks. In each group, the urine was analyzed by gas chromatography-mass spectrometry to measure the concentration of ketamine and its metabolites. Urinary frequency and urine volume were examined to investigate the urinary voiding functions. Mice bladders were excised for cDNA microarray and hematoxylin and eosin (HE) staining. The ketamine and metabolites were detected only in ketamine-treated mice urine. The voiding interval was reduced in the male mice group after 20 week ketamine administration. Additionally, the result of cDNA array analysis revealed a number of gene expression levels involved in chronic wound healing response and collagen accumulation, which were closely associated with fibrosis progression in the connective tissue. In HE staining of the bladder tissue, the ketamine-injected mice exhibited prominently denser blood vessel distribution in the submucosal layer. Based on the evidence in the present study, a mechanism that delineates fibrosis formation of urinary bladder induced by the pathogenesis of ketamine abuse can be constructed.

Clinical staging of ketamine-associated urinary dysfunction: a strategy for assessment and treatment

PURPOSE

To describe a clinical staging method linked to stepwise treatment indications for ketamine-associated urinary dysfunction (KAUD) based on review of our experience in management of KAUD patients and analysis of their clinical features.

METHODS

The eighty-one KAUD patients hospitalized from January 2008 to June 2014 were studied retrospectively. According to ketamine history, renal and liver function, bladder change and up urinary tract involvement, patients were categorized into a described model of three stages. Discriminant analysis was applied to validate the model. The void volume, micturition interval, nocturnal void frequency and pelvic pain and urgency/frequency (PUF) questionnaire score were, respectively, compared after treatments.

RESULTS

There were, respectively, 24, 47 and 10 patients in three stages. The duration of abuse varied (p = 0.047) correlated with clinical stages (p = 0.015, r = 0.268). The severity of LUTS was not significant. The creatinine, estimated glomerular filtration rate and liver function were worse in higher stages (p < 0.01), and the incidence of ureteral change and hydronephrosis was greater (p < 0.001). Based on the model, cross-validation confirmed 83.1 % cases were classified correctly. Twenty-four patients in stage I were treated with behavioral modification and pharmacotherapy, thirty-five patients in stage II with hydrodistention and six patients in stage III with surgical intervention due to rapid progression after conservative therapy. All patients in three stages demonstrated improvements in void volume, micturition interval, nocturnal void frequency and PUF score (all p < 0.05) after treatment.

CONCLUSION

Clinical staging could serve for assessment of progression, and the staging-based treatment is effective. This model still awaits further validation.

The fibrosis of ketamine, a noncompetitive N-methyl-d-aspartic acid receptor antagonist dose-dependent change in a ketamine-induced cystitis rat model

Ketamine abusers have greatly increased in number worldwide during recent years. The consumption of ketamine has increased, as have the number of published accounts of devastating urological sequelae. However, the mechanism of ketamine-associated urinary tract dysfunction remains unclear. This study was to evaluate the ketamine dose-dependency of ketamine-induced cystitis (KC) in a rat model. A total of 42 Sprague-Dawley rats (female, 10-week-old) were used. Each of the 7 KC rat models were induced by 1, 5, 10, 25 and 50 mg/kg ketamine intravenous injection for two weeks. For the sham group (n = 7), a phosphate-buffered saline (PBS) vehicle was used rather than ketamine hydrochloride. The cystometric parameters, histological examinations, staining for Masson's trichome, cytokeratin, toluidine blue and quantitative PCR were measured at two weeks following the intervention. The voiding interval gradually decreased depending upon the ketamine dose of 1, 5, 10, 25, or 50 mg/kg, respectively, and was decreased compared with Sham. Bladder capacity was decreased as ketamine dose increased. In particular, the increase of fibrosis and submucosal apoptosis were found according to the increase of the ketamine dose. The bladder apoptosis in the KC rat model makes the fibrotic bladder change, and led us to hypothesize that fibrosis could contribute to the lower urinary-tract symptoms. We suggest that according to the pathophysiology evidence, fibrosis induced by apoptosis plays a key role in KC.

Ketamine-induced ulcerative cystitis and bladder apoptosis involve oxidative stress mediated by mitochondria and the endoplasmic reticulum

Ketamine abusers develop severe lower urinary tract symptoms. The major aims of the present study were to elucidate ketamine-induced ulcerative cystitis and bladder apoptosis in association with oxidative stress mediated by mitochondria and the endoplasmic reticulum (ER). Sprague-Dawley rats were distributed into three different groups, which received normal saline or ketamine for a period of 14 or 28 days, respectively. Double-labeled immunofluorescence experiments were performed to investigate tight junction proteins for urothelial barrier functions. A TUNEL assay was performed to evaluate the distribution of apoptotic cells. Western blot analysis was carried out to examine the expressions of urothelial tight junction proteins, ER stress markers, and apoptosis-associated proteins. Antioxidant enzymes, including SOD and catalase, were investigated by real-time PCR and immunofluorescence experiments. Ketamine-treated rats were found to display bladder hyperactivity. This bladder dysfunction was accompanied by disruptions of epithelial cadherin- and tight junction-associated proteins as well as increases in the expressions of apoptosis-associated proteins, which displayed features of mitochondria-dependent apoptotic signals and ER stress markers. Meanwhile, expressions of mitochondria respiratory subunit enzymes were significantly increased in ketamine-treated bladders. Conversely, mRNA expressions of the antioxidant enzymes Mn-SOD (SOD2), Cu/Zn-SOD (SOD1), and catalase were decreased after 28 days of ketamine treatment. These results demonstrate that ketamine enhanced the generation of oxidative stress mediated by mitochondria- and ER-dependent pathways and consequently contributed to bladder apoptosis and urothelial lining defects. Such oxidative stress-enhanced bladder cell apoptosis and urothelial barrier defects are potential factors that may play a crucial role in bladder overactivity and ulceration.

Possible pathophysiology of ketamine-related cystitis and associated treatment strategies

Ketamine-related cystitis is characterized by ketamine-induced urinary frequency and bladder pain. It has become a serious problem in recent years. The most typical grossly pathological bladder change with ketamine related cystitis is a contracted bladder and bladder wall thickening. Ulcerative cystitis with an easily bleeding mucosa is a common cystoscopic finding. Microscopically, the urothelium is denuded and is infiltrated by inflammatory cells, such as mast cells and eosinophils. The pathogenesis of ketamine-related cystitis is complicated and involves many different pathways. Past evidence suggests a direct toxic effect, bladder barrier dysfunction, neurogenic inflammation, immunoglobulin-E-mediated inflammation, overexpression of carcinogenic genes, abnormal apoptosis and nitric oxide synthase-mediated inflammation contribute to the pathogenesis of ketamine-related cystitis. The first step to managing ketamine-related cystitis is always asking patients to cease ketamine. Medical treatment might be helpful in patients with early ketamine-related cystitis and abstinence from ketamine. Several case studies showed that the intravesical installation of hyaluronic acid and intravesical injection of botulinum toxin type A were effective for symptom relief in selected patients. For patients with irreversible pathological change, such as contracted bladder, augmentation enterocystoplasty might be the only solution to increase bladder capacity and relieve intractable bladder pain.

Prescription rate of medications potentially contributing to lower urinary tract symptoms and detection of adverse reactions by prescription sequence symmetry analysis

Background

The lower urinary tract symptoms (LUTS) increases with age and can have a significant effect on the quality of life of the patients. Elderly patients, who are often characterized by a decline in physiological functional and polypharmacy, are susceptible to adverse drug reactions to pharmacotherapy. LUTS can also be a side effect of medication. The purpose of this study was to investigate the possible association between the initiation of LUTS-causing drug therapy and the onset of LUTS.

Methods

Drug dispensing data at the individual level were retrieved from the CISA (Platform for Clinical Information Statistical Analysis: http://www.cisa.jp) database. A retrospective study was conducted by reviewing patients with LUTS who were dispensed drugs that increased the risk of LUTS between April 2011 and March 2012. Prescription sequence symmetry analysis (PSSA) was employed to investigate the associations between the dispensing of medicines of LUTS and that of LUTS-causing drugs.

Results

LUTS-causing drugs were frequently dispensed to patients with LUTS. The use of medications potentially contributing to LUTS was associated with polypharmacy [number of prescription drugs:12.13 ± 6.78 (user) vs. 5.67 ± 5.24 (nonuser)] but not patient age [ age: (71.38 ± 13.28 (user) vs. 70.45 ± 14.80 (nonuser)]. Significant adverse drug events were observed the use of donepezil, cyclophosphamide, antiparkinson drugs, antidepressant, diazepam, antipsychotic drugs for peptic ulcer, tiotropium bromide, and opioids.

Conclusions

The use of prescription LUTS-causing drugs was correlated with polypharmacy. The adverse drug events associated with LUTS-causing drugs were highly prevalent in elderly patients. To prevent of adverse drug events in patients with LUTS, pharmacists and physicians should regularly review medication lists and reduce the prescribed medicines.

Electronic supplementary material

The online version of this article (doi:10.1186/s40780-014-0004-1) contains supplementary material, which is available to authorized users.

Biological effect of ketamine in urothelial cell lines and global gene expression analysis in the bladders of ketamine‑injected mice

Ketamine is used clinically for anesthesia but is also abused as a recreational drug. Previously, it has been established that ketamine-induced bladder interstitial cystitis is a common syndrome in ketamine-abusing individuals. As the mechanisms underlying ketamine-induced cystitis have yet to be revealed, the present study investigated the effect of ketamine on human urothelial cell lines and utilized a ketamine-injected mouse model to identify ketamine-induced changes in gene expression in mice bladders. In the in vitro bladder cell line assay, ketamine induced cytotoxicity in a dose- and time-dependent manner. Ketamine arrested the cells in G1 phase and increased the sub-G1 population, and also increased the barrier permeability of these cell lines. In the ketamine-injected mouse model, ketamine did not change the body weight and bladder histology of the animals at the dose of 30 mg/kg/day for 60 days. Global gene expression analysis of the animals’ bladders following data screening identified ten upregulated genes and 36 downregulated genes induced by ketamine. A total of 52% of keratin family genes were downregulated, particularly keratin 6a, 13 and 14, which was confirmed by polymerase chain reaction analysis. Keratin 14 protein, one of the 36 ketamine-induced downregulated genes, was also reduced in the ketamine-treated mouse bladder, as determined by immunohistochemical analysis. This suggested that cytotoxicity and keratin gene downregulation may have a critical role in ketamine-induced cystitis.

Elevated serum IgE may be associated with development of ketamine cystitis

PURPOSE

Previous studies revealed bladder mast cell and eosinophil cell infiltration in patients with ketamine cystitis. Due to possible hypersensitivity in those with this condition we investigated the association of serum Ig, histology findings and symptoms in patients with ketamine cystitis.

MATERIALS AND METHODS

We evaluated patients with ketamine cystitis for maximal bladder capacity, serum IgE, IgG and IgM, and pain visual analog scale score. Bladder biopsies were assessed for mast cells and eosinophils. Patients with interstitial cystitis/bladder pain syndrome, acute bacterial cystitis and controls were also studied. We used the Mann-Whitney U test for nonparametric data to compare serum IgE among groups with p <0.017 considered significant.

RESULTS

Median serum IgE was significantly higher in the 20 patients with ketamine cystitis (205.5 IU/ml, IQR 36.9, 514.0) than in the 10 controls (33.4 IU/ml, IQR 13.5, 71.7, p = 0.015) and the 15 with acute bacterial cystitis (34.6 IU/ml, IQR 24.2, 101.9, p = 0.015). It was marginally higher than in the 13 patients with interstitial cystitis/bladder pain syndrome (65.8 IU/ml, IQR 11.9, 133.0, p = 0.029). Of patients with ketamine cystitis the median visual analog scale pain score was significantly higher in those with serum IgE greater than compared to less than 200 IU/ml. Maximal bladder capacity was significantly less in patients with ketamine cystitis who had higher IgE. Patients with severe or moderate bladder eosinophil infiltration had a greater visual analog scale score, higher serum IgE and smaller maximal bladder capacity than patients with no or mild eosinophil infiltration. Serum IgE and the visual analog scale score correlated significantly (r(2) = 0.318, p = 0.01).

CONCLUSIONS

Patients with ketamine cystitis had higher serum IgE than patients with interstitial cystitis/bladder pain syndrome or acute bacterial cystitis, or controls. Serum IgE and the severity of eosinophil infiltration were associated with bladder pain severity and small maximal bladder capacity.

Alteration of Urothelial Inflammation, Apoptosis, and Junction Protein in Patients with Various Bladder Conditions and Storage Bladder Symptoms Suggest Common Pathway Involved in Underlying Pathophysiology

OBJECTIVE

Lower urinary tract symptoms (LUTS) are common in various bladder disorders. This study investigated urothelial dysfunction and chronic inflammation in the urothelium in different types of lower urinary tract dysfunction (LUTD), which causes bladder storage symptoms.

METHODS

Bladder tissues were obtained from patients with LUTD including 17 with interstitial cystitis/bladder pain syndrome (IC/BPS), 15 with bladder outlet obstruction (BOO), 12 with spinal cord injury (SCI), 12 with recurrent urinary tract infection (UTI), 13 with ketamine related cystitis (KC) and 10 controls. The bladder specimens were investigated using immunofluorescence (IF) staining of the urothelial junction protein E-cadherin and the TUNEL assay for urothelial apoptosis. Mast cell activation was also measured by IF using tryptase for mucosal inflammation. Statistical analysis was performed using the Kruskal-Wallis and Wilcoxon rank-sum test and P-values less than 0.05 were considered significant.

RESULTS

Highly significant increases of mast cell infiltration were observed in patients with KC (7.8 ± 3.7), IC/BPS (4.6 ± 3.0), recurrent UTI (2.4 ± 1.2), SCI (3.7 ± 2.7), and BOO (5.1 ± 2.0) compared with controls (1.3 ± 1.2) (all p < 0.05). Statistically significant increases of apoptotic cells were observed in patients with KC (4.2 ± 1.5), IC/BPS (2.4 ± 1.7), SCI (2.4 ± 1.4), recurrent UTI (1.9 ± 2.4), and BOO (1.2 ± 1.1) compared with controls (0.08 ± 0.3) (all p < 0.05). Significantly decreased expression of E-cadherin in patients with IC/BPS (25.1 ± 16.3), KC (11.0 ± 11.3), and recurrent UTI (26.2 ± 5.0) was found compared to controls (42.4 ± 16.7) and patients with SCI (44.4 ± 18.8) or BOO (42.8 ± 14.3) (all P < 0.05).

CONCLUSION

Increased urothelial inflammation and urothelial cell apoptosis seem to share common pathophysiologies of various LUTDs that cause similar bladder symptoms.

Chronic hematuria and abdominal pain

An 18-year-old Asian woman with a history of substance abuse presented to the Emergency Department with right-sided abdominal pain and hematuria of several months duration. Physical examination revealed right upper quadrant and suprapubic tenderness. Liver function tests were normal. Urinalysis showed: large blood, 30-50 red blood cells/high-powered field, and no bacteria. She underwent a CT of the abdomen and pelvis following oral and intravenous contrast.

Purinergic signalling in the urinary tract in health and disease

Purinergic signalling is involved in a number of physiological and pathophysiological activities in the lower urinary tract. In the bladder of laboratory animals there is parasympathetic excitatory cotransmission with the purinergic and cholinergic components being approximately equal, acting via P2X1 and muscarinic receptors, respectively. Purinergic mechanosensory transduction occurs where ATP, released from urothelial cells during distension of bladder and ureter, acts on P2X3 and P2X2/3 receptors on suburothelial sensory nerves to initiate the voiding reflex, via low threshold fibres, and nociception, via high threshold fibres. In human bladder the purinergic component of parasympathetic cotransmission is less than 3 %, but in pathological conditions, such as interstitial cystitis, obstructed and neuropathic bladder, the purinergic component is increased to 40 %. Other pathological conditions of the bladder have been shown to involve purinoceptor-mediated activities, including multiple sclerosis, ischaemia, diabetes, cancer and bacterial infections. In the ureter, P2X7 receptors have been implicated in inflammation and fibrosis. Purinergic therapeutic strategies are being explored that hopefully will be developed and bring benefit and relief to many patients with urinary tract disorders.

Urological complications of illicit drug use

Illicit drug use is prevalent worldwide; over 24 million people are estimated to have used recreational drugs during the past month in the UK and USA alone. Illicit drug use can result in a wide spectrum of potential medical complications that include many urological manifestations. To ensure optimal care and treatment, urologists need to be cognizant of these complications in their patients, particularly among youths. Ketamine uropathy is thought to affect over one-quarter of ketamine users and can lead to severe lower urinary tract symptoms, as well as upper tract obstruction. Cannabis use has been associated with an increased risk of bladder cancer, prostate cancer and nonseminomatous germ cell tumours in case-control studies. Fournier's gangrene has been reported following injection of heroin and cocaine into the penis. Excessive use of cough medicines can lead to the development of radiolucent stones composed of ephedrine, pseudoephedrine and guaifenesin. As the current evidence is mostly limited to case reports and case series, future epidemiological studies are needed to fully address this issue.

Augmentation enterocystoplasty is effective in relieving refractory ketamine-related bladder pain

AIMS

To report our early results of augmentation enterocystoplasty (AE) for severe bladder pain associated with chronic ketamine cystitis (KC).

METHODS

We performed AE for 14 patients with refractory KC-related bladder pain, which is based on the criteria including severe bladder pain, urgency and frequency and/or upper urinary tract damage such as bilateral hydronephrosis, and contracted bladder. Every patient had been treated conservatively with medication or cystoscopic hydrodistention for at least 1 year before they had received surgical intervention. Video-urodynamic studies were obtained before AE and 3-6 months after surgery. Outcome measurements included visual analogue score (VAS) for pain, cystometric bladder capacity (CBC), maximum urinary flow rate (Qmax), post-void residual, and maximal detrusor pressure (Pdet). The patients' general satisfaction with regard to treatment outcome was also assessed by the Patient Perception of Bladder Condition (PPBC).

RESULTS

A total of 4 men and 10 women underwent this procedure as indicated. The mean age was 26.7 (ranged 20-38) years old and the duration of ketamine abuse was 3.82 years (ranged 2-7). Contracted bladder was noted in all patients, hydronephrosis in nine and vesicoureteral reflux (VUR) in eight. At 3-6 months after AE, VAS was remarkably improved from baseline to the end-point (8.29 ± 1.54 vs. 2.14 ± 1.51, P < 0.0001), CBC increased from 50.9 ± 15.7 to 309.2 ± 58.0 ml (P < 0.0001), Qmax increased from 6.94 ± 3.60 to 15.2 ± 5.51 ml/sec (P < 0.0001) and Pdet reduced from 29.7 ± 16.0 to 17.9 ± 8.2 cmH2 O (P = 0.008). All patients reported marked improvement in PPBC from 6.0 to 1.4 ± 0.89 (P < 0.0001). All hydronephrosis disappeared and VUR was resolved in five patients after AE with ureteral reimplantation.

CONCLUSIONS

This pilot study demonstrated that AE is effective in relieving refractory ketamine-related bladder pain and lower urinary tract symptoms.

Ketamine pharmacology: an update (pharmacodynamics and molecular aspects, recent findings)

For more than 50 years, ketamine has proven to be a safe anesthetic drug with potent analgesic properties. The active enantiomer is S(+)-ketamine. Ketamine is mostly metabolized in norketamine, an active metabolite. During "dissociative anesthesia", sensory inputs may reach cortical receiving areas, but fail to be perceived in some association areas. Ketamine also enhances the descending inhibiting serotoninergic pathway and exerts antidepressive effects. Analgesic effects persist for plasma concentrations ten times lower than hypnotic concentrations. Activation of the (N-Methyl-D-Aspartate [NMDA]) receptor plays a fundamental role in long-term potentiation but also in hyperalgesia and opioid-induced hyperalgesia. The antagonism of NMDA receptor is responsible for ketamine's more specific properties. Ketamine decreases the "wind up" phenomenon, and the antagonism is more important if the NMDA channel has been previously opened by the glutamate binding ("use dependence"). Experimentally, ketamine may promote neuronal apoptotic lesions but, in usual clinical practice, it does not induce neurotoxicity. The consequences of high doses, repeatedly administered, are not known. Cognitive disturbances are frequent in chronic users of ketamine, as well as frontal white matter abnormalities. Animal studies suggest that neurodegeneration is a potential long-term risk of anesthetics in neonatal and young pediatric patients.

Effects of long-term ketamine administration on rat bladder protein levels: a proteomic investigation using two-dimensional difference gel electrophoresis system

OBJECTIVES

Long-term ketamine abuse can affect the urinary system, resulting in interstitial cystitis-like syndrome. However, its pathogenesis remains unclear. In the present study, a proteomic approach of two-dimensional difference gel electrophoresis followed by matrix-assisted laser desorption/ionization time-of-light mass spectrometry was carried out to investigate the potential disease-associated proteins in a rat model of ketamine-associated cystitis.

METHODS

Rats were randomly assigned to control, normal saline, low dose of ketamine (10 mg/kg) and high-dose of ketamine (50 mg/kg) groups with six rats in each group. The two experimental groups were given ketamine hydrochloride i.p. daily, whereas the normal saline group rats were treated with saline. After 16 weeks of treatment, all bladders were excised, and samples from normal saline and high dose of ketamine groups were resolved in two-dimensional difference gel electrophoresis. Differentially expressed spots were excised and identified by matrix-assisted laser desorption/ionization time-of-light mass spectrometry. Phosphoprotein and non-phosphoprotein purification, histopathology, immunohistochemistry, and western blot were carried out in all groups.

RESULTS

Histological study showed hyperplastic epithelium and inflammatory cells infiltration in the high dose of ketamine-treated rat bladders. Two-dimensional difference gel electrophoresis revealed 30 altered expressions between the normal saline and high dose of ketamine-treated group. Among these proteins, two upregulated and two downregulated protein spots were all identified as smooth muscle protein-22/transgelin. Immunohistochemical staining and western blot analysis showed that the expression of total transgelin had no significant difference between groups. However, the expression of phosphorylated transgelin in the low-dose and high dose of ketamine groups was increased, whereas the non-phosphorylated transgelin was decreased when compared with the normal saline group.

CONCLUSIONS

Long-term ketamine abuse induces phosphorylation of transgelin in the bladder wall, and this might play an important role in the pathogenesis of ketamine-associated cystitis.