Expression of inducible nitric oxide synthase in primary culture of rat bladder smooth muscle cells by plasma from cyclophosphamide-treated rats

CGRP protects bladder smooth muscle cells stimulated by high glucose through inhibiting p38 MAPK pathway in vitro

This study aimed to explore the effect of calcitonin gene-related peptide (CGRP) on bladder smooth muscle cells (BSMCs) under high glucose (HG) treatment in vitro. BSMCs from Sprague-Dawley rat bladders were cultured and passaged in vitro. The third-generation cells were cultured and divided into control group, HG group, HG + CGRP group, HG + CGRP + asiatic acid (AA, p-p38 activator) group, CGRP group, AA group, HG + CGRP + CGRP-8-37 (CGRP receptor antagonist) group and HG + LY2228820 (p38 MAPK inhibitor) group. The cell viability, apoptosis, malondialdehyde (MDA) and superoxide dismutase (SOD) levels of BSMCs were observed by the relevant detection kits. The expressions of α-SM-actin, p38 and p-p38 were detected by qRT-PCR or Western blot analysis. Compared with the control group, the cell viability, SOD and α-SM-actin levels of BSMCs were decreased and apoptotic cells, MDA and p-p38 levels were increased after HG treatment, while these changes could be partly reversed when BSMCs were treated with HG and CGRP or LY2228820 together. Moreover, AA or CGRP-8-37 could suppress the effect of CGRP on BSMCs under HG condition. Our data indicate that CGRP protects BSMCs from oxidative stress induced by HG in vitro, and inhibit the α-SM-actin expression decrease through inhibiting the intracellular p38 MAPK signaling pathway.

Immunohistochemical and histological evaluations of cyclophosphamide-induced acute cardiotoxicity in wistar rats: The role of turmeric extract (curcuma)

Chemotherapy-induced cardiac derangement is a major concern in health sector. Cyclophosphamide as a chemotherapeutic agent induces acute cardiotoxicity through its toxic metabolite, acrolein. This study evaluated the effect of ethanol extract of turmeric on cyclophosphamide-induced acute cardiotoxicity in Wistar rats. Thirty-five healthy Wistar rats, weighing 200-250g were randomly assigned into 7 groups (Groups A, B, C, D, E, F and G) N=5. Group A was the control, group B was negative control, and group C was administered 200mg/kg of turmeric extract (orally) only. While groups B, D, E, F and G were all administered 100mg/kg cyclophosphamide (i.p) for 10 days. Groups D and E were administered 100mg/kg and 200mg/kg of turmeric extract (orally) respectively for 72 hours before cyclophosphamide administration. Groups F and G were concomitantly administered 100mg/kg cyclophosphamide (i.p) with doses of 100mg/kg and 200mg/kg of turmeric extract (orally) respectively. The rats were sacrificed under ketamine anesthesia (30mg/kg i.m). The left ventricle of the heart was excised. One-way ANOVA was used to analyze data. Results revealed that there was statistically significant (P<0.05) difference in body weight change, CK-MB, and LDH across all experimental groups; which were significantly lower in cyclophosphamide group. Histology and Immunohistochemistry revealed that there were morphological alterations in the myocardium of the left ventricle in group B while turmeric extract ameliorated cyclophosphamide-induced damage in the myocardium in other experimental groups. In conclusion, cyclophosphamide-induced myocardial alterations were significantly ameliorated through administration of ethanol extract of turmeric.

Therapy of the rat hemorrhagic cystitis induced by cyclophosphamide. Stable gastric pentadecapeptide BPC 157, L-arginine, L-NAME

We focused on the cyclophosphamide-induced hemorrhagic cystitis (100 mg/kg/day intraperitoneally throughout three days) as a particular NO-system disturbance, and therapy possibilities. We demonstrated that it may be attenuated by subsequent administration of the NOS substrate L-arginine (100 mg/kg/day intraperitoneally), aggravated by NOS-blocker L-NAME (5 mg/kg/day intraperitoneally), all influenced by the stable gastric pentadecapeptide BPC 157 (10 μg/kg/day, 10 ng/kg/day, intraperitoneally or perorally, in drinking water). Regularly, cyclophosphamide dose- and time-dependently induced severe hemorrhagic cystitis lesions, gross lesions, and corresponding urothelial necrosis, vesical edema, erosion, hemorrhage, inflammation, and ulceration, microscopically. The bladder wet weight dramatically increased. Functionally, already after first cyclophosphamide administration, there is an increased leak point pressure. Until the second cyclophosphamide administration, L-arginine consistently attenuated regular cyclophosphamide-induced severe hemorrhagic cystitis lesions, grossly and microscopically, but not functionally. L-NAME aggravated these lesions and eradicated beneficial effect of L-arginine when combined. BPC 157 administration after cyclophosphamide, given in either dose or in either regimen markedly attenuated all cyclophosphamide lesions, grossly, microscopically. The increase of the bladder wet weight was consistently attenuated. Functionally, increased leak point pressure was reversed to the values noted in normal rats. The similar findings were noted in rats that received BPC 157 together with L-NAME or L-arginine, given alone or combined. Thus, the lesions are NO-related based on the administration of L-NAME as well as administration of L-arginine, and their mutual interaction, and counteraction by BPC 157 application. Likewise, we reveal new therapeutic possibilities, emphasizing stable gastric pentadecapeptide BPC 157 and L-arginine, versus L-NAME in rats underwent cyclophosphamide-induced cystitis.

Cyclophosphamide induced stomach and duodenal lesions as a NO-system disturbance in rats: L-NAME, L-arginine, stable gastric pentadecapeptide BPC 157

We revealed a new point with cyclophosphamide (150 mg/kg/day intraperitoneally for 7 days): we counteracted both rat stomach and duodenal ulcers and increased NO- and MDA-levels in these tissues. As a NO-system effect, BPC 157 therapy (10 µg/kg, 10 ng/kg, intraperitoneally once a day or in drinking water, till the sacrifice) attenuated the increased NO- and MDA-levels and nullified, in rats, severe cyclophosphamide-ulcers and even stronger stomach and duodenal lesions after cyclophosphamide + L-NAME (5 mg/kg intraperitoneally once a day). L-arginine (100 mg/kg intraperitoneally once a day not effective alone) led L-NAME-values only to the control values (cyclophosphamide + L-NAME + L-arginine-rats). Briefly, rats were sacrificed at 24 h after last administration on days 1, 2, 3, or 7, and assessment included sum of longest lesions diameters (mm) in the stomach and duodenum, oxidative stress by quantifying thiobarbituric acid reactivity as malondialdehyde equivalents (MDA), NO in stomach and duodenal tissue samples using the Griess reaction. All these parameters were highly exaggerated in rats who underwent cyclophosphamide treatment. We identified high MDA-tissue values, high NO-tissue values, ulcerogenic and beneficial potential in cyclophosphamide-L-NAME-L-arginine-BPC 157 relationships. This suggests that in cyclophosphamide damaged rats, NO excessive release generated by the inducible isozyme, damages the vascular wall and other tissue cells, especially in combination with reactive oxygen intermediates, while failing endothelial production and resulting in further aggravation by L-NAME which was inhibited by L-arginine. Finally, BPC 157, due to its special relations with NO-system, may both lessen increased MDA- and NO-tissues values and counteract effects of both cyclophosphamide and L-NAME on stomach and duodenal lesions.

Protective Effect of Andrographis paniculata and Andrographolide on Cyclophosphamide-Induced Urothelial Toxicity

The protective effect of Andrograhis paniculata and andrographolide (ANDLE) against cyclophosphamide (CTX)-induced urothelial toxicity was investigated in this study. Pretreatment of Swiss albino mice with A paniculata extract (10 mg/dose/animal intraperitoneally [ip]) and ANDLE (500 μg/dose/animal ip) could significantly reduce CTX (1.5 nmol/kg body weight)-induced urothelial toxicity. Morphological and histopathological analysis of urinary bladder of CTX-treated mice showed severe inflammation and dark coloration, whereas A paniculata and ANDLE-treated mice showed almost normal bladder morphology. Elevation of urinary protein level (7.33±0.3 g/L) by CTX administration was reduced by A paniculata (3.78 ± 0.4 g/L) and ANDLE treatment (4.19 ± 0.1 g/L). Urinary urea N2level, which was elevated after 48 hours of CTX administration (24.25 ± 0.2 g/L) was found to be reduced by the treatment with A paniculata (14.19 ± 0.5 g/L) and ANDLE (15.79 ± 0.4 g/L). A decreased level of reduced glutahione (GSH) content in liver (2.81 ± 0.1 nmol/mg protein) and bladder (1.20 ± 0.2 nmol/mg protein) after CTX administration was also increased by the treatment with A paniculata (liver: 5.78 ± 0.3 nmol/mg protein; bladder: 2.96 ± 0.2 nmol/mg protein) and ANDLE (liver: 5.14 ± 0.3 nmol/mg protein; bladder: 2.84 ± 0.2 nmol/mg protein). Production of the proinflammatory cytokine, tumor necrosis factor-α, which was elevated during CTX administration, was found to be inhibited by A paniculata and ANDLE treatment. The lowered level of interleukin-2 and interferon-γ during CTX treatment was elevated by the administration of A paniculata and ANDLE.

Uroprotective effect of oleuropein in a rat model of hemorrhagic cystitis

Hemorrhagic cystitis is one of the devastating complications seen after receiving cyclophosphamide chemotherapy. Oleuropein is the most important phenolic compound of olive leaves that mediates most of its beneficial pharmacological properties. Herein, we investigated the possible uroprotective effect of oleuropein against cyclophosphamide induced hemorrhagic cystitis in a rat model. For this purpose, we measured bladder nitric oxide, reduced glutathione, catalase, tumor necrosis factor-alpha and vascular endothelial growth factor levels in addition to the bladder gene expression of intercellular adhesion molecule-1 after induction of hemorrhagic cystitis in the presence or absence of oleuropein. Histopathological examination of bladder tissues was also performed. After cyclophosphamide injection, we demonstrated a significant decrease in bladder reduced glutathione (39%) and catalase (55.4%) levels and a significant increase of nitric oxide (5.6 folds), tumor necrosis factor-alpha (3.3 folds), vascular endothelial growth factor (2 folds) and intercellular adhesion molecule-1 (8 folds) bladder contents when compared to those in normal control rats. Administration of oleuropein induced a marked elevation in bladder reduced glutathione (37.8%), catalase (100.4%) with a prominent reduction of bladder nitric oxide (40%), tumor necrosis factor-alpha (35.9%) and vascular endothelial growth factor (56.2%) levels along with downregulation of intercellular adhesion molecule-1 bladder expression (73.1%) in comparison to cyclophosphamide treated rats levels. Our data demonstrated that oleuropein counteracts the harmful effects of cyclophosphamide on the bladder through its antioxidant and anti-inflammatory activities. Oleuropein exerts a definite uroprotective effect against cyclophosphamide induced hemorrhagic cystitis in rats.

Protective effect of N-acetylcysteine on cyclophosphamide-induced cardiotoxicity in rats

Cyclophosphamide (CP) is an oxazaphosphorine nitrogen mustard alkylating drug used for the treatment of chronic and acute leukemias, lymphoma, myeloma, and cancers of the breast and ovary. It is known to cause severe cardiac toxicity. This study investigated the protective effect of N-Acetylcysteine (NAC) on CP-induced cardiotoxicity in rats. CP resulted in a significant increase in serum aminotransferases, creatine kinase (CK), lactate dehydrogenase(LDH) enzymes, asymmetric dimethylarginine and tumor necrosis factor-α and significant decrease in total nitrate/nitrite(NOx). In cardiac tissues, a single dose of CP (200mg/kg, i.p.) resulted in significant increase in malondialdehyde and NOx and a significant decrease in reduced glutathione content, glutathione peroxidase, catalase, and superoxide dismutase activities. Interestingly, Administration of NAC (200mg/kg, i.p.) for 5 days prior to CP attenuates all the biochemical changes induced by CP. These results revealed that NAC attenuates CP-induced cardiotoxicity by inhibiting oxidative and nitrosative stress and preserving the activity of antioxidant enzymes.

Histopathological assessment of inflammation and expression of inflammatory markers in patients with ketamine-induced cystitis

The aim of the current study was to evaluate the histopathological features of inflammation and the expression levels of inflammatory markers in tissue samples from patients with ketamine-induced cystitis. Bladder biopsy samples for histological analysis were obtained from 23 patients (18 men and 5 women) with a self-reported history of ketamine use and who were treated for cystitis at the Tri-Service General Hospital of Taipei, Taiwan. Immunohistochemical staining for cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), matrix metallopeptidase-9 (MMP-9), mammalian target of rapamycin (mTOR), and phosphorylated 40S ribosomal protein S6 (Phos-S6) was performed. The results revealed urothelial atypia in all patients, and intravascular eosinophil accumulation in 22 patients. Histopathological features included denuded urothelial mucosa, ulceration, collagen deposition, smooth muscle degeneration and vessel proliferation. Tissue samples were immunopositive for all of the inflammation markers, including the urothelium, vessel walls, and smooth muscle. COX-2 staining revealed a significant difference between the inflammatory levels in the urothelium and smooth muscle, and iNOS staining differed significantly between inflammatory levels in smooth muscle (p=0.029). A positive correlation was observed between the percentage of Phos-S6-positive cells and the levels of inflammation in the urothelium. These results add to the descriptive literature on the histopathological aspects of ketamine-induced cystitis, emphasizing the inflammatory nature and a possible role for proteins such as COX-2, iNOS and Phos-S6 in the degree of inflammation.

Inhibition of nitric oxide synthase prevents muscarinic and purinergic functional changes and development of cyclophosphamide-induced cystitis in the rat

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.

Evaluation of the effects of S-methylisothiourea hemisulfate, an inducible nitric oxide synthase inhibitor, on the healing of colonic anastomosis in rats

PURPOSE

To evaluate the effects of S-methylisothiourea hemisulfate (SMT) on the healing of colonic anastomosis in rats.

METHODS

Sixty rats Wistar were distributed into two groups of 30 animals: experimental (E) and control C). The animals of experimental group received intraperitoneal SMT at 50 mg/kg/dose every 12 hours for 72 hours. The control group received intraperitoneal saline at the same volume of SMT. The rats were subdivided into subgroups groups of 10 for euthanasia on the third, seventh, and 14th postoperative days (POD). We evaluated clinical and weight evolution, breaking strength and histopathology; also, a blood sample was collected for serum dosage of nitrite/nitrate.

RESULTS

There was more vascular neoformation (p=0.006) and granulation (p=0.002) in the E3 group, and more mononuclear infiltrates in the C3 group (p=0.041). There was also more edema in the C14 group (p=0.008). There was no statistically significant difference in breaking strength, nitrite/nitrate dosage, and the remaining histopathological parameters.

CONCLUSION

The use of S-methylisothiourea hemisulfate improved the healing of colonic anastomosis in rats on the third postoperative day by accelerating the proliferative stage of healing, but without interfering with the breaking strength of the anastomosis.

Uroprotective effects of curcumin in cyclophosphamide-induced haemorrhagic cystitis paradigm

The possible uroprotective effects of curcumin have been addressed in the current study. Haemorrhagic cystitis was induced by challenging male Swiss albino rats with a single dose of cyclophosphamide (150 mg/kg, i.p.). Curcumin (200 mg/kg, i.p.) was administered for 10 consecutive days followed by a single dose of cyclophosphamide. Haemorrhagic cystitis was well characterized morphologically and biochemically. The hallmark of this toxicity was marked congestion, oedema and extravasation in rat urinary bladder, as well as a marked desquamative damage to the urothelium and severe inflammation in the lamina propria. Leucocytic infiltration was also observed and determined by histopathological examination. Serum level of tumour necrosis factor-alpha was notably elevated associated with apparent hypokalaemia and hyponatraemia. Bladder contents of adenosine triphosphate, reduced glutathione and glutathione-S-transferase activity were markedly reduced. Malondialdehyde level, myeloperoxidase activity and urinary nitrite-nitrate levels, expressed as nitric oxide, were dramatically increased. Prior administration of curcumin ahead of cyclophosphamide challenge improved all the biochemical and histologic alterations induced by the cytotoxic drug. Based on these broad findings, it could be concluded that curcumin has proven uroprotective efficacy in this cyclophosphamide haemorrhagic cystitis model, possibly through modulating the release of inflammatory endocoids, namely tumour necrosis factor-alpha and nitric oxide, improving the energy status and restoring the oxidant/antioxidant balance.

Rolipram, a specific type-4 phosphodiesterase inhibitor, inhibits cyclophosphamide-induced haemorrhagic cystitis in rats

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.

Activity and Expression of Nitric Oxide Synthase in Rat Bladder after Sacral Neuromodulation

The aim of our study is to investigate the effects of chronic sacral neuromodulation on Nitric Oxide (NO) metabolism in the rat bladder. 26 female Sprangue-Dawley rats were considered: group I, normal control rats; group II, a sham treatment, in whom catheters for electrical stimulation were placed in the S1 foramen bilaterally and left in place for 21 days, without performing neuromodulation; group III in whom electrical sacral neuromodulation was performed for 21 days. Finally a cystectomy was performed and the bladder biopsy specimens were sent for immunostaining with n-NOS and i-NOS. Morphological and immunohistochemical analysis was carried out, and evaluated in urothelial cells, endothelial cells and muscle fibers of the muscularis propria. Differences between the 3 groups were analyzed by Student Newman-Keuls test. We could observe that urothelial and endothelial i-NOS (37.00±4.69 and 59.00±7.42 respectively) and urothelial n-NOS (36.80±7.85) expression are significantly increased in neuromodulated rats, compared to groups 1 and 2 (p < 0.005). In conclusion, the increase of i-NOS expression on endothelial cells after sacral neuromodulation could be in some way related to angiogenetic responses in the microvascular structures; the increase of n-NOS and i-NOS expression on urothelial cells can suggest that NO is able to influence the plasticity of bladder response, inducing the release of messengers within the urothelium. This study can therefore improve our understanding of the mechanisms of sacral neuromodulation on chronic bladder dysfunction; further studies will need to better demonstrate the role of angiogenesis in the bladder after sacral neuromodulation and to investigate the effects of neuromodulation in rats with chronically induced bladder dysfunction.

Neural Upregulation in Interstitial Cystitis

Interstitial cystitis (IC) is a syndrome of bladder hypersensitivity with symptoms of urgency, frequency, and chronic pelvic pain. Although no consensus has been reached on the underlying cause of IC, several pathophysiologic mechanisms, including epithelial dysfunction, mast cell activation, and neurogenic inflammation, have been proposed. Despite multiple different causes of urinary cystitis, the bladder's response to cystitis is limited and typical. Animal experiments have shown upregulation of proteinase-activated receptors, tryptase, beta-nerve growth factor, inducible nitric oxide synthase, nuclear transcription factor-kappaB, c-Fos, phosphodiesterase 1C, cyclic adenosine monophosphate (cAMP)-dependent protein kinase, and proenkephalin B. After the noxious stimulus has abated, downregulation of genes appears to follow. Distention of the bladder results in the release of adenosine triphosphate (ATP) from urothelial cells, which activates purinergic P2X3 receptors. Activation by ATP of P2X3-expressing afferents is a fundamental signaling factor in bladder sensation and appears to play a role in bladder reflexes. Fos proteins present in spinal cord neurons have been shown to be upregulated in animals that have undergone cyclophosphamide-induced chemical cystitis. These and other findings suggest that neural upregulation occurs both peripherally and centrally in subjects with chronic cystitis. It is unclear whether neural mechanisms and inflammation are the cause of IC or the result of other initiating events. Neural upregulation is known to play a role in the chronicity of pain, urgency, and frequency and represents an exciting area of research that may lead to additional treatments and a better understanding of IC.

Effects of intravesical instillation of cyclooxygenase-2 inhibitor on the expression of inducible nitric oxide synthase and nerve growth factor in cyclophosphamide-induced overactive bladder

OBJECTIVE

To examine the effects of intravesical cyclooxygenase-2 (COX-2) inhibitors on the expression of inducible nitric oxide synthase (iNOS) and nerve growth factor (NGF) in cyclophosphamide (CYP)-induced overactive bladder (OAB).

MATERIALS AND METHODS

In all, 40 Sprague-Dawley rats were divided into control, OAB, and COX-2 inhibitor-treated groups. OAB was induced by an intraperitoneal injection with CYP. Cystometry was performed in all rats and, in half of the OAB rats, a COX-2 inhibitor was administered intravesically. The bladders of all rats were stained immunohistochemically for iNOS and NGF.

RESULTS

In the OAB rats, the contraction interval and intercontraction interval were significantly shorter than in control rats, and the contraction time and pressure were significantly greater. In the COX-2 inhibitor-treated rats, the contraction interval and intercontraction interval were significantly longer than in the OAB rats, and the contraction time was significantly shorter. On immunohistochemical staining, there was no iNOS activity and NGF activity was minimally localized in the mucosa and submucosa in the control group. In the OAB rats, NGF activity in the mucosa and submucosa were increased, and there was greater expression of iNOS in all layers and of NGF in detrusor; in the COX-2 inhibitor-treated rats, their expression was less in all layers.

CONCLUSIONS

Intravesical instillation with COX-2 inhibitors can reduce CYP-induced bladder hyperactivity and expression of iNOS and NGF. Intravesical instillation with COX-2 inhibitors can be considered as a possible treatment for OAB.

15-Deoxy-Δ12,14-prostaglandin J2 attenuates development of cyclophosphamide-induced cystitis in rats

OBJECTIVES

To investigate whether an endogenous prostaglandin (PG) D2 metabolite, 15-deoxy-Delta12,14-PGJ2 (15d-PGJ2), can attenuate cyclophosphamide (CYP)-induced cystitis in the rat.

METHODS

Male Sprague-Dawley rats received a single intraperitoneal injection of CYP (200 mg/kg). In a separate group of animals, 15d-PGJ2 (10 and 100 microg/kg intraperitoneal bolus 10 minutes before and 24 hours after CYP injection) or a selective inducible nitric oxide synthase (iNOS) inhibitor, N-(3-(aminomethyl)benzyl)acetamidine ([1400W] 10 mg/kg intraperitoneal bolus 10 minutes before and 12 and 24 hours after CYP injection), was administered. At 48 hours after CYP injection, the rats were killed, and tissues were removed for evaluation of cystitis.

RESULTS

CYP injection resulted in severe cystitis. 15d-PGJ2, as well as 1400W, significantly reduced the increase in plasma protein extravasation (Evans blue dye method), iNOS enzymatic activity, urinary excretion of nitric oxide metabolites, and myeloperoxidase activity in the bladder caused by CYP. Moreover, 15d-PGJ2 significantly decreased the cytokine interleukin-1beta in the bladder. In addition, 15d-PGJ2 significantly reduced the degree of CYP-induced bladder tissue damage and increase in immunohistochemical staining for iNOS in the bladder.

CONCLUSIONS

These results indicate that 15d-PGJ2 can attenuate the development of CYP-induced cystitis by suppression of cytokine production and iNOS induction. Thus, treatment with cyclopentenone prostaglandins such as 15d-PGJ2 may be effective against CYP-induced cystitis.

Oxidative stress plays a role in diabetes-induced bladder dysfunction in a rat model

OBJECTIVES

To evaluate the oxidative status of the bladder 8 weeks after diabetes induction. Oxidative stress has recently been implicated in the pathogenesis of diabetes complications, but its role in diabetic cystopathy has not been studied.

METHODS

Sprague-Dawley rats were divided into three groups: control (n = 11), diuretic control (5% sucrose drink; n = 6), and streptozotocin-induced diabetic group (n = 14). Eight weeks later, the bladders were dissected. We measured the antioxidant scavenging enzymes (catalase and superoxide dismutase)-like activity and the levels of the thiobarbituric acid reactive substances, as a marker of lipid peroxidation. We also examined the levels of inducible nitric oxide synthase and apoptosis in the bladders.

RESULTS

We found a statistically significant reduction in the catalase-like activity in the bladders from the diabetic group compared with the other groups (P = 0.017, diabetic versus control); the difference in the superoxide dismutase-like activity was not statistically significant among the groups. The thiobarbituric acid reactive substances levels were significantly greater in the diabetic compared with other groups (131.9 +/- 47.5, 46.7 +/- 17.9, and 60.9 +/- 25.4 nmol/mg protein in the diabetic, control, and diuretic group, respectively, P = 0.006, diabetic versus control). Immunohistochemical and apoptosis studies showed a statistically significant increased number of inducible nitric oxide synthase-positive cells and apoptotic cells in the diabetic bladder smooth muscle cells (P <0.001).

CONCLUSIONS

Our findings showed that oxidative stress occurred in the bladders of the STZ-diabetic rats and was not mediated by diuresis. The oxidative damage of the smooth muscle cells may be a contributory factor in diabetic cystopathy.

Altered inducible nitric oxide synthase expression and nitric oxide production in the bladder of cats with feline interstitial cystitis

PURPOSE

Alterations in nitric oxide (NO) levels have been demonstrated in some humans with interstitial cystitis (IC) as well as in chemically induced animal models of cystitis. Thus, in the current study we investigated whether inducible NO synthase (iNOS) mediated NO production is altered in the bladder of cats with a naturally occurring model of IC termed feline IC (FIC).

MATERIALS AND METHODS

We examined iNOS expression using Western immunoblotting and baseline NO production using an NO microsensor from smooth muscle and mucosal bladder strips in 9 healthy cats and 6 diagnosed with FIC.

RESULTS

There was a significant increase in baseline NO production in cats with FIC compared with that in healthy cats in smooth muscle and mucosal strips. This production was not ablated in the absence of extracellular Ca (100 microM egtazic acid) or following incubation with the calmodulin antagonist trifluoroperazine (20 microM), indicating iNOS mediated Ca independent NO production. Release was significantly decreased following incubation with the NOS antagonist L-NAME (N-nitro-L-arginine methyl ester) (100 microM). Furthermore, immunoblotting revealed a trend toward increased iNOS expression in smooth muscle and mucosal strips from FIC cats but not from healthy cats.

CONCLUSIONS

In light of previous findings that the barrier property of the urothelial surface is disrupted in FIC and iNOS mediated increase in NO alters barrier function in other types of epithelium our findings suggest that iNOS dependent NO production may have a role in epithelial barrier dysfunction in FIC.

Involvement of inducible nitric oxide synthase in renal failure after mild hemorrhage

The role of iNOS in rats after mild hemorrhaging was examined in this study. A mild hemorrhage (17% of total blood) induced a decrease of systemic blood pressure and heart rate, transiently followed by gradual recovery. The hemorrhage caused expression of renal iNOS mRNA and an increase in systemic NO products at 1 h after bleeding. Serum creatinine and serum urea nitrogen (UN) increased progressively up to 5 h after bleeding. Light microscopic findings showed that some inflammatory monocytes, mainly consisting of neutrophil, often existed in the glomerular capillaries, eosinophilic changes were observed in the cytoplasm at the proximal tubules, and urinary casts existed in the uriniferous space at 5 h after bleeding. The selective iNOS inhibitor, S-methylisothiourea (MTU), suppressed hemorrhagic expression of renal iNOS mRNA and systemic NO products, suppressed the increases of serum creatinine and UN, and improved renal histological aggravations induced by hemorrhaging. We speculated that MTU caused the negative circuit to suppress the renal failure through a decrease of NO generation. These results in the present study showed that iNOS expression induced by mild hemorrhaging at the early phase did participate in the development of renal failure.

Involvement of nitric oxide and hyperbaric oxygen in the pathogenesis of cyclophosphamide induced hemorrhagic cystitis in rats

PURPOSE

We evaluated the relationship between nitric oxide and hyperbaric oxygenation in the pathogenesis and treatment of cyclophosphamide induced hemorrhagic cystitis in rats.

MATERIALS AND METHODS

Cyclophosphamide (100 mg/kg) was injected in male Sprague-Dawley rats for cystitis induction. Animals were treated before and the day after cyclophosphamide injection with 100 mg/kg of the nitric oxide substrate L-arginine, 20 mg/kg of the nonselective nitric oxide synthase inhibitor L-NG-nitroarginine methyl ester and 20 mg/kg of the selective inducible nitric oxide synthase inhibitor S-methylisothiourea. Animals were exposed to hyperbaric oxygen (2.8 atmospheres absolute for 90 minutes twice daily) with or without the administration of L-arginine and nitric oxide synthase inhibitors.

RESULTS

Cyclophosphamide injection resulted in severe cystitis. S-methylisothiourea produced marked inhibition of cyclophosphamide induced bladder tissue damage. L-arginine and L-NG-nitroarginine methyl ester failed to a show meaningful protective effect. Hyperbaric oxygen protected the bladder only against ulceration. Moreover, hyperbaric oxygen did not contribute to the protective effects of L-arginine, L-NG-nitroarginine methyl ester or S-methylisothiourea.

CONCLUSIONS

Nitric oxide produced by inducible nitric oxide synthase is an important mediator in the pathogenesis of cyclophosphamide induced cystitis. Hyperbaric oxygen has a beneficial effect on repairing bladder damage rather than on bladder protection.

Inducible nitric oxide synthase inhibition in cyclophosphamide induced hemorrhagic cystitis in rats

Cyclophosphamide (CP) is an antineoplastic agent used alone or in combination with other chemotherapeutic agents for the treatment of many neoplastic diseases. Hemorrhagic cystitis (HC) is a major potential toxicity and dose limiting side effect of CP. Recently, it has been shown that endogenous inflammatory mediators are involved in cystitis by increasing nitric oxide (NO) production in target tissue. The aim of this study was to evaluate the relationship between NO and CP induced hemorrhagic cystitis HC in rats. A total of 30 female Spraque-Dawley rats were divided into 4 groups. Group 1 served as control, three groups received single dose of CP (100 mg/kg) intraperitoneally (i.p.): group 2 received CP only. Group 3 received the NO precursor L-arginine (80 mg/kg/day), and group 4 received the selective inducible NO synthase (iNOS) inhibitor S-methylisothiourea (SMT; 20 mg/kg/day) before and the day after cyclophosphamide injection. CP injection resulted in severe cystitis. SMT but not L-arginine produced marked inhibition of CP induced bladder damage. We concluded that NO produced by iNOS, is an important mediator in the pathogenesis of CP induced cystitis.

Phenotypic modulation of cultured bladder smooth muscle cells and the expression of inducible nitric oxide synthase

Phenotypic modulation of smooth muscle is associated with various pathological conditions, including bladder dysfunction. Cytoskeletal dynamics modulate the cell phenotype and were recently shown to be involved in regulation of inducible nitric oxide synthase (iNOS). We tested the hypothesis that the cell differentiation status affects iNOS expression, and that iNOS is preferentially expressed in immature dedifferentiated bladder smooth muscle cells (BSMC). Isolated at BSMC were put into different stages of differentiation by serum deprivation on laminin-coated plates in the presence of IGF-I and by interaction with Rho signaling and actin polymerization. iNOS and smooth muscle-myosin heavy chain (SM-MHC) protein expression were investigated with Western blot analysis. Our results showed iNOS protein in BSMC exposed to interleukin-1 beta (2 ng/ml) + TNF-alpha (50 ng/ml). Growth of BSMC in serum-free medium on laminin in the presence of IGF-I increased SM-MHC expression, whereas cytokine-induced iNOS was inhibited. Disruption of F-actin with latrunculin B (0.5 microM) potentiated iNOS expression and decreased SM-MHC expression. Rho inhibition with C3 (2.5 microg/ml) increased iNOS expression, whereas SM-MHC expression was slightly decreased. Rho-kinase inhibition with Y-27632 (10 microM) mediated a decrease in iNOS and a slight increase in SM-MHC expression. In conclusion, the capacity of BSMC to express iNOS was negatively correlated to differentiation status measured as SM-MHC expression. Actin cytoskeletal dynamics and Rho signaling are involved in regulation of cytokine-induced iNOS expression in BSMC. Phenotypic changes and impairment in actin cytoskeleton formation may potentiate cytokine activation and in turn increase nitric oxide production in the bladder during disease.

Nerve-mediated bladder contraction is impaired by cytokines: involvement of inducible nitric oxide synthase

We investigated the possible involvement of inducible nitric oxide synthase (iNOS) in the effect of cytokines on neuromuscular function in isolated rat bladder strips. Bladder strips were incubated in cell culture medium for 24 h with or without tumour necrosis factor-alpha (TNF-alpha)+interleukin-1beta. Mechanical activity in response to electrical field stimulation and carbachol was recorded in organ baths. Both the electrical field stimulation- and carbachol-induced contractions were reduced by the incubation. The electrical field stimulation-induced contraction was significantly further impaired after prolonged exposure to TNF-alpha+interleukin-1beta. This impairment was restored by dexamethasone, the iNOS inhibitor aminoguanidine and partially by brain-derived neurotrophic factor (BDNF). In contrast, carbachol-induced contractions were not affected by cytokines. iNOS protein expression was detected in cytokine-incubated bladder strips by immunohistochemistry and Western blot analysis. The results demonstrated that TNF-alpha+interleukin-1beta impaired nerve-mediated bladder contractions. Aminoguanidine, and to some extent BDNF, exerted neuroprotective effects.

Expression of nitric oxide synthase in bladder smooth muscle cells: regulation by cytokines and L-arginine

PURPOSE

The expression and regulation of the different isoforms of nitric oxide synthase (NOS) in bladder smooth muscle cells are controversial and to our knowledge have not yet been studied systematically. Therefore, the expression and regulation of NOS were studied in rat bladder smooth muscle cells after stimulation with cytokines, lipopolysaccharide and L-arginine.

MATERIALS AND METHODS

Primary cell cultures were prepared from rat bladders. The expression of NOS mRNA was examined by reverse transcriptase-polymerase chain reaction and inducible NOS (iNOS) protein expression was studied by Western blot analysis and immunohistochemistry. Nitrite accumulation in the culture medium was determined by the Griess assay. The expression of iNOS was also studied immunohistochemically in whole bladder strips stimulated by cytokines.

RESULTS

NOS mRNA expression was not detected in unstimulated cells. Stimulating bladder smooth muscle cells with a cytokine mixture of interferon-gamma, tumor necrosis factor-alpha and interleukin-1beta induced iNOS mRNA and protein expression. The combination of interleukin-1beta plus tumor necrosis factor-alpha appeared to be crucial for iNOS induction in bladder smooth muscle cells. Exposing bladder smooth muscle cells to lipopolysaccharide did not induce iNOS. Adding L-arginine increased nitrite accumulation in cytokine mixture stimulated bladder smooth muscle cells, while iNOS positive cells were detected in the smooth muscle layer of cytokine mixture stimulated bladder strips.

CONCLUSIONS

NOS was not detected in unstimulated bladder smooth muscle cells. However, bladder smooth muscle has the potential to express iNOS when exposed to cytokines known to be produced during urinary tract infection.

Gene expression profiling of mouse bladder inflammatory responses to LPS, substance P, and antigen-stimulation

Inflammatory bladder disorders such as interstitial cystitis (IC) deserve attention since a major problem of the disease is diagnosis. IC affects millions of women and is characterized by severe pain, increased frequency of micturition, and chronic inflammation. Characterizing the molecular fingerprint (gene profile) of IC will help elucidate the mechanisms involved and suggest further approaches for therapeutic intervention. Therefore, in the present study we used established animal models of cystitis to determine the time course of bladder inflammatory responses to antigen, Escherichia coli lipopolysaccharide (LPS), and substance P (SP) by morphological analysis and cDNA microarrays. The specific aim of the present study was to compare bladder inflammatory responses to antigen, LPS, and SP by morphological analysis and cDNA microarray profiling to determine whether bladder responses to inflammation elicit a specific universal gene expression response regardless of the stimulating agent. During acute bladder inflammation, there was a predominant infiltrate of polymorphonuclear neutrophils into the bladder. Time-course studies identified early, intermediate, and late genes that were commonly up-regulated by all three stimuli. These genes included: phosphodiesterase 1C, cAMP-dependent protein kinase, iNOS, beta-NGF, proenkephalin B and orphanin, corticotrophin-releasing factor (CRF) R, estrogen R, PAI2, and protease inhibitor 17, NFkB p105, c-fos, fos-B, basic transcription factors, and cytoskeleton and motility proteins. Another cluster indicated genes that were commonly down-regulated by all three stimuli and included HSF2, NF-kappa B p65, ICE, IGF-II and FGF-7, MMP2, MMP14, and presenilin 2. Furthermore, we determined gene profiles that identify the transition between acute and chronic inflammation. During chronic inflammation, the urinary bladder presented a predominance of monocyte/macrophage infiltrate and a concomitant increase in the expression of the following genes: 5-HT 1c, 5-HTR7, beta 2 adrenergic receptor, c-Fgr, collagen 10 alpha 1, mast cell factor, melanocyte-specific gene 2, neural cell adhesion molecule 2, potassium inwardly-rectifying channel, prostaglandin F receptor, and RXR-beta cis-11-retinoic acid receptor. We conclude that microarray analysis of genes expressed in the bladder during experimental inflammation may be predictive of outcome. Further characterization of the inflammation-induced gene expression profiles obtained here may identify novel biomarkers and shed light into the etiology of cystitis.