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Lee H, Koh BH, Peri LE, Woodward HJ, Perrino BA, Sanders KM, Koh SD. Role of detrusor PDGFRα + cells in mouse model of cyclophosphamide-induced detrusor overactivity. Sci Rep 2022; 12:5071. [PMID: 35332235 PMCID: PMC8948241 DOI: 10.1038/s41598-022-09155-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/14/2022] [Indexed: 11/28/2022] Open
Abstract
Cyclophosphamide (CYP)-induced cystitis is a rodent model that shares many features common to the cystitis occurring in patients, including detrusor overactivity (DO). Platelet-derived growth factor receptor alpha positive (PDGFRα+) cells have been proposed to regulate muscle excitability in murine bladders during filling. PDGFRα+ cells express small conductance Ca2+-activated K+ channels (predominantly SK3) that provide stabilization of membrane potential during filling. We hypothesized that down-regulation of the regulatory functions of PDGFRα+ cells and/or loss of PDGFRα+ cells generates the DO in CYP-treated mice. After CYP treatment, transcripts of Pdgfrα and Kcnn3 and PDGFRα and SK3 protein were reduced in detrusor muscle extracts. The distribution of PDGFRα+ cells was also reduced. Inflammatory markers were increased in CYP-treated detrusor muscles. An SK channel agonist, CyPPA, increased outward current and hyperpolarization in PDGFRα+ cells. This response was significantly depressed in PDGFRα+ cells from CYP-treated bladders. Contractile experiments and ex vivo cystometry showed increased spontaneous contractions and transient contractions, respectively in CYP-treated bladders with a reduction of apamin sensitivity, that could be attributable to the reduction in the SK conductance expressed by PDGFRα+ cells. In summary, PDGFRα+ cells were reduced and the SK3 conductance was downregulated in CYP-treated bladders. These changes are consistent with the development of DO after CYP treatment.
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Affiliation(s)
- Haeyeong Lee
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, 89557, USA.
| | - Byoung H Koh
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Lauren E Peri
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Holly J Woodward
- The Roslin Institute, The University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK
| | - Brian A Perrino
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Sang Don Koh
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, 89557, USA
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Ali FF, Abdelzaher WY, Ibrahim RA, Elroby Ali DM. Amelioration of estrogen-induced endometrial hyperplasia in female rats by hemin via heme-oxygenase-1 expression, suppression of iNOS, p38 MAPK, and Ki67. Can J Physiol Pharmacol 2019; 97:1159-1168. [PMID: 31505119 DOI: 10.1139/cjpp-2019-0287] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Although heme oxygenase-1 (HO-1) is part of an endogenous defense system implicated in the homeostatic response, its role in cell proliferation and tumor progression is still controversial. Endometrial hyperplasia (EH) is associated with high risk of endometrial cancer (EC). Therefore, we aimed to evaluate the effect of hemin, a HO-1 inducer, against EH. Thirty-two female rats (60-70 days old) were divided into 4 groups treated for 1 week: vehicle control group, hemin group (25 mg/kg; i.p. 3 times/week), estradiol valerate (EV) group (2 mg/kg per day, p.o.), and hemin plus EV group. Sera were obtained for reduced glutathione level. Uterine malondialdehyde, superoxide dismutase, total nitrite/nitrate, and interleukin-1β levels were estimated. HO-1 and p38 mitogen-activated protein kinase expressions were obtained in uterine tissue. Uterine histological and immunohistochemical assessment of iNOS and Ki67 were also done. Results demonstrated that upregulation of HO-1 expression in hemin plus EV rats led to amelioration of EH which was confirmed with histological examination. This was associated with significant decrease in oxidative stress parameters, p38 mitogen-activated protein kinase expression, and interleukin-1β level. Also, uterine iNOS and Ki67 expressions were markedly suppressed. In conclusion, upregulation of HO-1 expression via hemin has ameliorative effect against EH through its antioxidant, anti-inflammatory, and antiproliferative actions.
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Affiliation(s)
- Fatma F Ali
- Department of Medical Physiology, Faculty of Medicine, Minia University, Egypt
| | | | - Randa Ahmed Ibrahim
- Department of Histology and Cell Biology, Faculty of Medicine, Minia University, Egypt
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Abstract
Urinary tract infection (UTI) is one of the most common bacterial infections in humans, and the majority are caused by uropathogenic Escherichia coli (UPEC). The rising antibiotic resistance among UPEC and the frequent failure of antibiotics to effectively treat recurrent UTI and catheter-associated UTI motivate research on alternative ways of managing UTI. Abundant evidence indicates that the toxic radical nitric oxide (NO), formed by activation of the inducible nitric oxide synthase, plays an important role in host defence to bacterial infections, including UTI. The major source of NO production during UTI is from inflammatory cells, especially neutrophils, and from the uroepithelial cells that are known to orchestrate the innate immune response during UTI. NO and reactive nitrogen species have a wide range of antibacterial targets, including DNA, heme proteins, iron-sulfur clusters, and protein thiol groups. However, UPEC have acquired a variety of defence mechanisms for protection against NO, such as the NO-detoxifying enzyme flavohemoglobin and the NO-tolerant cytochrome bd-I respiratory oxidase. The cytotoxicity of NO-derived intermediates is nonspecific and may be detrimental to host cells, and a balanced NO production is crucial to maintain the tissue integrity of the urinary tract. In this review, we will give an overview of how NO production from host cells in the urinary tract is activated and regulated, the effect of NO on UPEC growth and colonization, and the ability of UPEC to protect themselves against NO. We also discuss the attempts that have been made to develop NO-based therapeutics for UTI treatment.
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Kilic O, Akand M, Karabagli P, Piskin MM. Hemostatic Efficacy and Histopathological Effects of Ankaferd Blood Stopper in an Experimental Rat Model of Cyclophosphamide-induced Hemorrhagic Cystitis. Urology 2016; 94:313.e7-313.e13. [PMID: 27215482 DOI: 10.1016/j.urology.2016.05.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 04/14/2016] [Accepted: 05/14/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To evaluate the hemostatic efficacy and histopathological effects of Ankaferd Blood Stopper (ABS) in an experimental rat model of cyclophosphamide-induced (CYP) hemorrhagic cystitis (HC). MATERIALS AND METHODS Forty male Sprague-Dawley rats were included in the study. Firstly, 10 rats were divided equally into 2 groups where the first group was administered only an intraperitoneal (i.p.) injection of normal saline to constitute the negative control group (CON). The remaining 5 rats were administered only a single i.p. injection of CYP (without any further treatment) for induction of HC to constitute the positive control group (HC). Subsequently, the remaining 30 rats, which also received i.p. CYP for induction of HC, were divided into 3 groups to which intravesical saline (SAL group), epinephrine (EPN group), and ABS (ANK group) were administered for 3 consecutive days. Ten days after the third instillation, cystectomy was performed for histopathological examination. Specimens were evaluated for presence of congestion, edema, necrosis, ulceration, and regenerated epithelium, and scores were given for each parameter according to the severity. RESULTS No statistically significant difference was observed for congestion, edema, necrosis, and ulceration between HC-SAL, and also between CON-ANK groups (all P values >.05). There was a significant difference for total scores between EPN and ANK groups (P = .009). There was statistically significant difference for regenerating epithelium between CON-EPN, CON-ANK, HC-ANK, and SAL-ANK groups. CONCLUSION Intravesical administration of ABS is at least as efficacious as EPN in terms of congestion, edema, necrosis, and ulceration. Moreover, ABS can be considered as a better option in inducing regenerating epithelium than EPN.
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Affiliation(s)
- Ozcan Kilic
- Department of Urology, School of Medicine, Selcuk University, Konya, Turkey
| | - Murat Akand
- Department of Urology, School of Medicine, Selcuk University, Konya, Turkey.
| | - Pinar Karabagli
- Department of Pathology, School of Medicine, Selcuk University, Konya, Turkey
| | - Mehmet Mesut Piskin
- Department of Urology, Meram Medical School, Necmettin Erbakan University, Konya, Turkey
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Fathollahi A, Daneshgari F, Hanna-Mitchell AT. Melatonin and Its Role in Lower Urinary Tract Function: An Article Review. Curr Urol 2015; 8:113-8. [PMID: 26889129 DOI: 10.1159/000365701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 02/20/2015] [Indexed: 01/19/2023] Open
Abstract
This article reviewed the results of studies done on animals that assessed effects of melatonin on bladder function. Melatonin does not change strip relaxation on its own. However, pre-treatment with melatonin decreases contractile responses induced by phenylephrine, acetylcholine, bethanechol and KCl in a dose-dependent manner. The contractile responses induced by the direct calcium channel openers are significantly decreased by melatonin pre-treatment. It also binds to Ca(2+)-activated calmodulin, and prevents it from activating myosin light-chain kinase. It may have direct effects on ion channels which are responsible for regulating bladder contraction. Its other mode of action on bladder occurs via the brain GABAA receptor. Melatonin is an antioxidant. In bladder, treatment with melatonin prevents elevations in malondialdehyde levels, reverses changes in glutathione levels, and decreases myeloperoxidase levels compared with oxidative injury. It can normalize age induced bladder dysfunction through its antioxidant effects, inhibiting smooth muscle contractility directly and restoring impaired contractility via normalization of Ca(2+) handling and sensitizations pathways. It attenuates the severity of cystitis and inflammation. Mast cell proliferation and activation are increased in cystitis, but decrease by melatonin treatment. Also, there is a decrease in expression levels of pro-inflammatory cytokines after melatonin treatment.
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Affiliation(s)
- Ali Fathollahi
- Urology Institute, Case Western Reserve University, Cleveland, OH., USA
| | - Firouz Daneshgari
- Urology Institute, Case Western Reserve University, Cleveland, OH., USA
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Inhibition of nitric oxide synthase prevents muscarinic and purinergic functional changes and development of cyclophosphamide-induced cystitis in the rat. BIOMED RESEARCH INTERNATIONAL 2014; 2014:359179. [PMID: 24982868 PMCID: PMC4058690 DOI: 10.1155/2014/359179] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 04/15/2014] [Accepted: 04/30/2014] [Indexed: 12/28/2022]
Abstract
Nitric oxide (NO) has pivotal roles in cyclophosphamide- (CYP-) induced cystitis during which mucosal nitric oxide synthase (NOS) and muscarinic M5 receptor expressions are upregulated. In cystitis, urothelial muscarinic NO-linked effects hamper contractility. Therefore we wondered if a blockade of this axis also affects the induction of cystitis in the rat. Rats were pretreated with saline, the muscarinic receptor antagonist 4-DAMP (1 mg/kg ip), or the NOS inhibitor L-NAME (30 mg/kg ip) for five days. 60 h before the experiments the rats were treated with saline or CYP. Methacholine-, ATP-, and adenosine-evoked responses were smaller in preparations from CYP-treated rats than from saline-treated ones. Pretreatment with 4-DAMP did not change this relation, while pretreatment with L-NAME normalized the responses in the CYP-treated animals. The functional results were strengthened by the morphological observations; 4-DAMP pretreatment did not affect the parameters studied, namely, expression of muscarinic M5 receptors, P1A1 purinoceptors, mast cell distribution, or bladder wall enlargement. However, pretreatment with L-NAME attenuated the differences. Thus, the current study provides new insights into the complex mechanisms behind CYP-induced cystitis. The NO effects coupled to urothelial muscarinic receptors have a minor role in the development of cystitis. Inhibition of NOS may prevent the progression of cystitis.
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Mechanism for the protective effect of diallyl disulfide against cyclophosphamide acute urotoxicity in rats. Food Chem Toxicol 2014; 64:110-8. [DOI: 10.1016/j.fct.2013.11.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/18/2013] [Accepted: 11/20/2013] [Indexed: 11/17/2022]
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Zhang QH, Zhou ZS, Lu GS, Song B, Guo JX. Melatonin Improves Bladder Symptoms and May Ameliorate Bladder Damage via Increasing HO-1 in Rats. Inflammation 2012; 36:651-7. [DOI: 10.1007/s10753-012-9588-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Radice S, Carnovale C, Antoniazzi S, Zuccotti G, Perrone V, Piazza A, Clementi E. A case of recurrent acute haemorrhagic cystitis associated with salbutamol and beclomethasone use in a paediatric patient. J Paediatr Child Health 2012; 48:620-1. [PMID: 22758901 DOI: 10.1111/j.1440-1754.2012.02495.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Santos AA, Leal PC, Edelweiss MIA, Lopes TG, Calixto JB, Morrone FB, Campos MM. Effects of the compounds MV8608 and MV8612 obtained from Mandevilla velutina in the model of hemorrhagic cystitis induced by cyclophosphamide in rats. Naunyn Schmiedebergs Arch Pharmacol 2010; 382:399-407. [PMID: 20809237 DOI: 10.1007/s00210-010-0555-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 08/16/2010] [Indexed: 12/29/2022]
Abstract
Hemorrhagic cystitis (HC) is a common side effect observed in patients under chemotherapy with cyclophosphamide (CYP). The urotoxic side effects of CYP are attributed to the metabolic compound acrolein, and can be partially prevented by the uroprotector agent 2-mercaptoethene sulfate (Mesna). The present study analyzed the anti-inflammatory and the antinociceptive effects of compounds MV8608 and MV8612 obtained from Mandevilla velutina in the rat model of CYP-induced HC. Male Wistar rats were used (six to eight per group, 220-250 g). HC was induced by a single administration of CYP (100 mg/kg, ip). Three behavioral parameters--breathing rate, closing of the eyes, and specific posture--were used as nociception indexes, and scored at different time intervals (15-180 min) after cystitis induction. As inflammatory parameters, hemorrhage presence, edema formation, and bladder weight were determined at 24 h after CYP administration. The neutrophil migration was assessed by means of myeloperoxidase (MPO activity), 4 h after cystitis induction. As expected, Mesna treatment was able to reduce in a significant manner all the inflammatory and the nociceptive parameters induced by CYP. Of note, the administration of MV8608 significantly inhibited the hemorrhage formation and the neutrophil recruitment, while the MV8612 treatment markedly reduced the bladder weight, without interfering with neutrophil influx. Interestingly, the treatment with either MV8608 or MV8612 markedly reduced the nociceptive responses. The present results clearly indicate that MV8608 and MV8612 might represent important alternatives to prevent side effects, especially the nociception, following chemotherapy with CYP.
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Affiliation(s)
- André A Santos
- Programa de Pós-Graduação em Biologia Celular e Molecular, PUCRS, Porto Alegre, Rio Grande do Sul, Brazil
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Miyamoto Y, Ohshida K, Sasago K. A protein assay for heme oxygenase-1 (HO-1) induced by chemicals in HepG2 cells. J Toxicol Sci 2009; 34:709-14. [DOI: 10.2131/jts.34.709] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Yohei Miyamoto
- Toxicology and Pharmacokinetics Laboratories, Pharmaceutical Research Laboratories, Toray Industries, Inc
| | - Keiyu Ohshida
- Toxicology and Pharmacokinetics Laboratories, Pharmaceutical Research Laboratories, Toray Industries, Inc
| | - Kaori Sasago
- Toxicology and Pharmacokinetics Laboratories, Pharmaceutical Research Laboratories, Toray Industries, Inc
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Sakura M, Masuda H, Matsuoka Y, Yokoyama M, Kawakami S, Kihara K. Rolipram, a specific type-4 phosphodiesterase inhibitor, inhibits cyclophosphamide-induced haemorrhagic cystitis in rats. BJU Int 2008; 103:264-9. [PMID: 18710439 DOI: 10.1111/j.1464-410x.2008.07948.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To investigate the protective roles of type 4 phosphodiesterase (PDE4) inhibitor in cyclophosphamide (CYP)-induced haemorrhagic cystitis, as the PDE4 inhibitor has anti-inflammatory effects but its characterization is still unknown in urinary tract diseases. MATERIALS AND METHODS In female Sprague-Dawley rats, CYP was administered intraperitoneally and bladders were harvested 24 h after CYP injection. In another group, rolipram as a PDE4 inhibitor was administered before CYP treatment. The effects and mechanisms of CYP with/without rolipram pretreatment were evaluated by microscopic features, bladder wet weight, myeloperoxidase (MPO) activity, nitric oxide (NO)-metabolite production and expression levels of inflammation-related genes. RESULTS CYP injection resulted in severe cystitis. Pretreatment with rolipram significantly reduced the increase in bladder wet weight and MPO activity, and ameliorated histological inflammatory changes caused by CYP. The levels of inflammation-related transcripts including inducible NO synthase (iNOS), interleukin-1beta and tumour necrosis factor-alpha, induced by CYP, were down-regulated significantly by pretreatment with rolipram. Also, rolipram reduced the NO-metabolite production and iNOS protein expression in the immunohistochemical examination. CONCLUSION These results indicate that rolipram can attenuate the development of CYP-induced cystitis in rats by suppressing cytokine production and iNOS induction. Thus, treatment with PDE4 inhibitor has potential clinical implications of the prevention of bladder inflammatory diseases.
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Affiliation(s)
- Mizuaki Sakura
- Department of Urology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
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Zinc protoporphyrin IX, a heme oxygenase-1 inhibitor, demonstrates potent antitumor effects but is unable to potentiate antitumor effects of chemotherapeutics in mice. BMC Cancer 2008; 8:197. [PMID: 18620555 PMCID: PMC2478682 DOI: 10.1186/1471-2407-8-197] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2008] [Accepted: 07/11/2008] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND HO-1 participates in the degradation of heme. Its products can exert unique cytoprotective effects. Numerous tumors express high levels of HO-1 indicating that this enzyme might be a potential therapeutic target. In this study we decided to evaluate potential cytostatic/cytotoxic effects of zinc protoporphyrin IX (Zn(II)PPIX), a selective HO-1 inhibitor and to evaluate its antitumor activity in combination with chemotherapeutics. METHODS Cytostatic/cytotoxic effects of Zn(II)PPIX were evaluated with crystal violet staining and clonogenic assay. Western blotting was used for the evaluation of protein expression. Flow cytometry was used to evaluate the influence of Zn(II)PPIX on the induction of apoptosis and generation of reactive oxygen species. Knock-down of HO-1 expression was achieved with siRNA. Antitumor effects of Zn(II)PPIX alone or in combination with chemotherapeutics were measured in transplantation tumor models. RESULTS Zn(II)PPIX induced significant accumulation of reactive oxygen species in tumor cells. This effect was partly reversed by administration of exogenous bilirubin. Moreover, Zn(II)PPIX exerted potent cytostatic/cytotoxic effects against human and murine tumor cell lines. Despite a significant time and dose-dependent decrease in cyclin D expression in Zn(II)PPIX-treated cells no accumulation of tumor cells in G1 phase of the cell cycle was observed. However, incubation of C-26 cells with Zn(II)PPIX increased the percentage of cells in sub-G1 phase of the cells cycle. Flow cytometry studies with propidium iodide and annexin V staining as well as detection of cleaved caspase 3 by Western blotting revealed that Zn(II)PPIX can induce apoptosis of tumor cells. B16F10 melanoma cells overexpressing HO-1 and transplanted into syngeneic mice were resistant to either Zn(II)PPIX or antitumor effects of cisplatin. Zn(II)PPIX was unable to potentiate antitumor effects of 5-fluorouracil, cisplatin or doxorubicin in three different tumor models, but significantly potentiated toxicity of 5-FU and cisplatin. CONCLUSION Inhibition of HO-1 exerts antitumor effects but should not be used to potentiate antitumor effects of cancer chemotherapeutics unless procedures of selective tumor targeting of HO-1 inhibitors are developed.
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Protective effects of bilirubin against cyclophosphamide induced hemorrhagic cystitis in rats. J Urol 2008; 179:1160-6. [PMID: 18206168 DOI: 10.1016/j.juro.2007.10.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2007] [Indexed: 11/22/2022]
Abstract
PURPOSE The end product of the heme oxygenase pathway, bilirubin, is the most abundant endogenous antioxidant in mammals. We report the heme oxygenase-1 mediated production of bilirubin and its cytoprotective roles in cyclophosphamide induced hemorrhagic cystitis in rats. MATERIALS AND METHODS Female Sprague-Dawley rats received intraperitoneal administration of cyclophosphamide. In the first experiment hemin (an inducer of heme oxygenase-1) with or without zinc protoporphyrin IX (an inhibitor of heme oxygenase activity) was given before cyclophosphamide injection. Endogenous bilirubin production was analyzed in bladder tissues immunohistochemically. In another experiment bilirubin solution was administered before the cyclophosphamide injection. Changes in bladder weight, microscopic feature and expression levels of inducible nitric oxide synthase, proinflammatory cytokines and heme oxygenase were evaluated using polymerase chain reaction and immunostaining. RESULTS Bilirubin was generated in bladders with cyclophosphamide induced cystitis, especially in the urothelium and suburothelium. Hemin pretreatment provided increased production of endogenous bilirubin, which was decreased by zinc protoporphyrin IX. In an evaluation of the roles of bilirubin exogenous bilirubin administration ameliorated cyclophosphamide induced inflammatory changes and reduced the increase in bladder weight. The elevated expression of inducible nitric oxide synthase and interleukin-1beta in cyclophosphamide induced cystitis was significantly down-regulated by exogenously applied bilirubin. The expression of heme oxygenase-1 and 2 was not modified by bilirubin administration. CONCLUSIONS Cyclophosphamide induced hemorrhagic cystitis is accompanied by endogenous bilirubin production through heme oxygenase-1 induction in the bladder. Bilirubin has cytoprotective roles in association with the down-regulation of inducible nitric oxide synthase expression. Our results suggest that bilirubin may have therapeutic potential against bladder inflammatory insults such as cyclophosphamide induced cystitis.
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