Intravesical oxyhemoglobin initiates bladder overactivity in conscious, normal rats

PURPOSE: To investigate whether intravesical oxyhemoglobin, a nitric oxide scavenger, changes bladder activity in normal rats. MATERIALS AND METHODS: Oxyhemoglobin was given intravesically at different concentrations to conscious, female Sprague-Dawley rats undergoing continuous cystometry. RESULTS: Intravesical oxyhemoglobin increased bladder activity in a concentration-dependent way. At a concentration of 2.5 x 10-4 M (n = 8), micturition pressure (p <0. 01), basal pressure (p <0.01), and residual volume (p <0.05) increased, and bladder capacity (p <0.001) and micturition volume (p <0.001) decreased. The effect of oxyhemoglobin was reduced or abolished by L-arginine (200 mg./kg.-1), given intra-arterially near the bladder, and was enhanced by the guanylate cyclase inhibitor, ODQ (0.5 and 1 mg./kg.-1). The K+ channel opener, ZD6169 100 ng.ml. -1, given intravesically for 1 hour prior to instillation of oxyhemoglobin, reduced or completely prevented the bladder activity induced by oxyhemoglobin. CONCLUSIONS: Intravesical oxyhemoglobin induces bladder overactivity, probably by interfering with nitric oxide (NO) generated in the urothelium or suburothelially. NO may be involved in the regulation of the threshold for afferent firing in the bladder.     

INVOLVEMENT OF HYPOGASTRIC AND PELVIC NERVES FOR CONVEYING CYSTITIS INDUCED NOCICEPTION IN CONSCIOUS RATS

PURPOSE: We determined the sites of the antinociceptive action of morphine in the experimental model of cyclophosphamide induced cystitis and investigated the afferent nerve fibers involved in nociception transmission originating from the bladder. MATERIALS AND METHODS: Cyclophosphamide (200 mg./kg.) given intraperitoneally was used to induce cystitis in male rats and their behavior was observed and scored. The effect of 2 mg./kg. systemic morphine given intravenously on cyclophosphamide induced behavioral modifications was tested when administered alone and after 100 microg. naloxone per rat given intrathecally at the L1 to L2 or L6 to S1 level. The spinal antinociceptive effect of morphine was also tested when administered intrathecally alone at 10, 100 and 200 microg. per rat at L1 to L2, alone at 100 microg. per rat at L1 to L2 or L6 to S1, alone at 100 microg. per rat at L1 to L2 and L6 to S1 simultaneously, alone at 200 microg. per rat at L1 to L2 and after 100 microg. naloxone per rat given intrathecally at L6 to S1 at 100 microg. per rat at L1 to L2. RESULTS: Cyclophosphamide induced marked modifications in the behavior of the rats, including a decreased breathing rate, eye closing and specific postures. Morphine given intravenously reversed these behavioral disorders and this reversal was completely prevented by pretreatment with intrathecal naloxone. A dose of 100 microg. per rat given intrathecally also reversed these behavioral disorders by about 25% at the L1 to L2 and L6 to S1 levels. In addition, a dose of 100 microg. morphine per rat administered intrathecally and simultaneously at L1 to L2 and L6 to S1 produced an effect equal to the sum of those observed when administered separately, that is about 50%, whereas morphine at an intrathecal dose of 200 microg. at L1 to L2 produced the same effect as 100 microg. given intrathecally at the same level or at L6 to S1 (25%). Also, 100 microg. naloxone per rat administered intrathecally at L6 to S1 prevented the effect of 100 microg. morphine at L1 to L2. CONCLUSIONS: These results confirm the previously reported antinociceptive effect of systemic morphine in this model of cyclophosphamide cystitis, suggest that this antinociceptive action is completely located at the spinal site and most importantly demonstrate by the pharmacological approach and behavioral analysis that nociceptive sensations originating from the bladder are conveyed by hypogastric and pelvic nerves in this cyclophosphamide cystitis model in the conscious rat.     

Whole bladder photodynamic therapy for orthotopic superficial bladder cancer in rats: a study of intravenous and intravesical administration of photosensitizers

PURPOSE: Photodynamic therapy after intravenous injection of Photofrin (QLT Phototherapeutics, Vancouver, British Columbia, Canada) results in a contracted bladder and skin photosensitivity, which limits its clinical application. In an attempt to overcome these limitations photodynamic therapy after intravesical instillation of Photofrin or 5-aminolevulinic acid (ALA) in an orthotopic rat bladder tumor model was explored and compared with intravenous Photofrin for photodynamic therapy efficacy and phototoxicity. MATERIALS AND METHODS: At 2 weeks after bladder implantation of 1.5 x 10(6) AY-27 tumor cells animals were randomly grouped. Photofrin was administered (5 mg./kg. intravenously and 2 mg./ml. intravesically). The ALA concentration for intravesical instillation was 300 mM. Whole bladder photodynamic therapy with graded doses of light (lambda = 630 nm.) was performed 4 hours after drug administration. Tumor control and complications were evaluated. RESULTS: Photodynamic therapy with intravenous Photofrin plus 100 J./cm.(2) light resulted in severe bladder damage. Of 10 rats 6 died and 2 of the 10 that received 50 J./cm.(2) died. There were no photodynamic therapy related deaths in groups receiving intravesical instillation of Photofrin or ALA that also received 50 to 100 J./cm.(2) Median survival in rats treated with ALA intravesically plus 75 J./cm.(2) (77 days), Photofrin intravesically plus 50 (67) or 100 J./cm.(2) (76) and Photofrin intravenously plus 50 J./cm.(2) (60) were significantly different from that in controls (44). CONCLUSIONS: Intravesical instillation of Photofrin or ALA can achieve the same photodynamic therapy efficacy as intravenous Photofrin in this orthotopic rat bladder tumor model with less phototoxicity to normal tissues.     

Effects of sensitization on the permeability of urothelium in guinea pig urinary bladder.

Permeability of the guinea pig urinary bladder was investigated in a model of experimental cystitis induced by intravesical antigen challenge following sensitization. Guinea pigs were sensitized by intraperitoneal injections of ovalbumin (10 mg./kg.) given on days 1, 3, and 5. The studies described were done four weeks after the last injection. Controls (injected with saline) were used at the same time as sensitized animals. Each group (control and sensitized), was divided into two subgroups; guinea pigs challenged with intravesical ovalbumin (10 mg./ml., one ml.) and those receiving one ml. saline intravesically. Immediately following the antigen (or saline) challenge, one ml. of 14C-urea urea was placed into the bladder for two hours. We examined the peripheral blood concentrations of 14C-urea at periods of time up to 120 minutes. There was a progressive increase in the blood level of 14C-urea with time only in the sensitized group challenged with antigen (ovalbumin). There was no 14C-urea present in the blood of the sensitized group without antigen challenge, or in either unsensitized group. We also measured isotope concentration in the bladders and found a significantly higher concentration of isotope in the bladders from ovalbumin-treated sensitized guinea pigs. We believe that this animal model of cystitis is an improvement over previous models because of its physiological relevance. In this model, cystitis is produced without mechanical or chemical damage to the bladder mucosa. A discussion of the model in relation to interstitial cystitis is presented.     

Experimental cytoxan cystitis and prevention by acetylcysteine

Cytoxan (cyclophosphamide) given to rats intraperitoneally produced a severe cystitis within four hours with marked inflammatory edema and hemorrhagic ulcerations of the mucosa. An in vivo staining test with methylene blue showed deep staining of the urothelium as has been demonstrated with other types of urothelial injuries; uninjured urothelium does not stain. The cytoxan cystitis is probably not due to cytoxan itself, but to a breakdown product acrolein, an aldehyde appearing in the urine. Rat experiments demonstrated that acrolein instilled intravesically produced a cystitis similar to that found with cytoxan injected intraperitoneally. The cystitis due either to cytoxan or acrolein was prevented by simultaneous intravesical administration of an aldehyde inactivating agent, acetylcysteine (mucomyst).     

Intravesical Morphine Analgesia after Bladder Surgery

Purpose

A recent demonstration of peripheral opioid receptors suggested the possibility of delivering morphine locally into the bladder after reimplantation for ameliorating the discomfort of postoperative bladder irritation with spasms. Since we do not use bladder drainage after reimplantation, dripping a morphine solution into the bladder permits contact with the urothelium between voidings. A pilot trial using an arbitrary concentration was subjectively beneficial for treating these patients postoperatively. We now report a prospective randomized study evaluating the effectiveness and dosage of various concentrations of intravesical morphine infusions.

Materials and Methods

A total of 52 children undergoing ureteral reimplantation was randomized to receive 1 of 3 concentrations of intravesical morphine (0.05, 0.375 or 0.5 mg./ml.). A small feeding tube remained in the bladder to drip a continuous infusion postoperatively. Subsequent postoperative pain was treated with meperidine, acetaminophen and codeine, and/or a belladonna and opium suppository. During each shift a nurse assisted the child in assessing pain using a Baker-Wong faces scale. Bladder infusion was discontinued after day 3 postoperatively and plasma morphine levels were measured on the first morning postoperatively. Kruskal-Wallis and paired t tests were used to evaluate significance.

Results

Patients reported greater pain in the group infused with 0.05 mg./ml. on 4 of 6 shifts on the first 2 days postoperatively. No difference was noted on postoperative day 3. Plasma morphine was undetectable by high pressure liquid chromatography.

Conclusions

This study offers objective evidence that bladder morphine infusion is effective for ameliorating postoperative pain in the first 48 hours after intravesical ureteral reimplantation. The dose given today is 0.5 mg./ml. delivered at 0.04 ml./kg. per hour.     

The morphological and functional changes in rat bladder following photodynamic therapy with phthalocyanine photosensitization

We have studied photodynamic therapy (PDT) in the rat bladder with a new photosensitizer, aluminium sulfonated phthalocyanine (AlSPc) given intravenously and intravesically. The microscopic distribution of photosensitizer fluorescence in the bladder wall was studied by laser fluorescence microscopy. Prior to PDT the bladder capacity and compliance were assessed by filling cystometry. Intravesical red light (675 nm.) from a copper vapour pumped dye laser was used to activate the photosensitizer using light doses of 20 to 200 J/cm2. Urodynamic and histologic changes were studied at intervals for up to three months. The fluorescence studies showed that AlSPc was eliminated from the deeper muscle layers more quickly than from the superficial layers of the bladder wall so that by 24 hours there was four times as much fluorescence from the mucosa and lamina propria compared to the deeper muscle. Control bladders illuminated with laser light alone showed no effects at these light doses. Animals treated 24 hours after sensitization showed a reduction in bladder capacity of up to 78% (20 J/cm2. light and 1.5 mg./kg.AlSPc). An initial reduction in compliance recovered in two weeks after low doses (0.5 mg./kg.) of AlSPc but was still abnormal at three months after higher doses (1.5 mg./kg.); though there was no long term histologic abnormality seen. Aluminium sulfonated phthalocyanine is a promising photosensitizer for bladder photodynamic therapy and using low doses of the drug it is possible to produce a superficial necrosis without muscle damage across a range of light doses. This heals by epithelial regeneration with no long term functional impairment. Direct absorption of this photosensitizer following intravesical administration seems unreliable.     

Inhibitory roles of peripheral nitrergic mechanisms in capsaicin-induced detrusor overactivity in the rat

OBJECTIVES: To investigate the peripheral role of nitric oxide (NO) in capsaicin-induced detrusor overactivity (DO), as exogenously applied vanilloids can evoke NO release in urothelial cells but its functional role has not yet been reported. MATERIALS AND METHODS: The effects of N(G)-nitro-l-arginine methyl ester (L-NAME), an inhibitor of NO synthase (NOS), on bladder activity during intravesical capsaicin (30 microm) instillation were examined by using continuous infusion cystometry in urethane-anaesthetized rats. L-NAME was administered intravenously (i.v., 20 mg/kg), intrathecally (i.t., 270 microg/rat), intracerebroventricularly (i.c.v., 270 microg/rat) or intravesically (10 mg/mL) before or during capsaicin instillation. RESULTS: During cystometry with intravesical saline infusion, L-NAME injected i.v., i.t. and i.c.v., but not intravesically, significantly increased the intercontraction intervals (ICI) and L-NAME injected i.v., but not i.t., i.c.v. or intravesically, increased the maximum voiding pressure (MVP) without affecting the baseline pressure. Capsaicin instillation induced DO evidenced by a significant reduction in the ICI. L-NAME administered i.v. further decreased the ICI and increased the MVP and the baseline pressure during capsaicin instillation. Co-intravesical application of capsaicin and L-NAME also similarly enhanced capsaicin-induced DO. However, L-NAME injected i.t. or i.c.v. had no effect on capsaicin-induced DO. The excitatory effects of i.v and intravesical L-NAME on the ICI, MVP and baseline pressure during capsaicin infusion were significantly suppressed by desensitization of C-fibre afferent pathways by capsaicin pretreatment (125 mg/kg s.c., 4 days before cystometry). CONCLUSION: These results indicate that locally released NO can suppress DO induced by capsaicin-mediated C-fibre activation and that central NO pathways are not involved in capsaicin-induced DO.     

The fluorescence biodistribution and kinetics of aminolevulinic acid induced protoporphyrin IX in the bladder of a rat model with orthotopic urothelial carcinoma

PURPOSE: Photodynamic therapy is an alternative intravesical therapy modality for superficial bladder cancer. Aminolevulinic acid (ALA) induces the production of the endogenous photosensitizer protoporphyrin IX (PpIX). We compared intravenous versus intravesical administration of ALA and established the proper timing and dose of ALA for photodynamic therapy. To characterize the distribution of ALA in rat bladder tumor and normal bladder layers a cooled charge coupled device camera was used. MATERIALS AND METHODS: A total of 40 female Fisher F344 rats were used as test animals, including 36 inoculated with AY-27 tumor cells intravesically. PpIX accumulation was investigated by fluorescence microscopy comparing 100 and 300 mg./kg. intravenous administration with a 100 mg./ml. intravesical dose of ALA. Three areas of urothelium, submucosa and muscularis of the bladder wall were chosen for analysis. The software used allowed semiquantitative analysis by calculating the mean fluorescence count plus or minus standard error of mean within any chosen area on the fluorescence image. RESULTS: In this study the highest fluorescence difference in PpIX accumulation in tumor and the normal epithelium to the muscularis layer was achieved at 2 hours with intravenous administration (7:1 to 50:1). The highest absolute fluorescence levels were observed at 2 hours with the 100 mg./kg. intravenous dose and at 4 hours with the higher 300 mg./kg. dose. The difference in fluorescence intensity in tumor tissue to normal urothelium was 2:1 to 3:1 at 2 hours. At 4 hours it was less than 2:1. After intravesical administration no difference in PpIX accumulation in tumor and normal urothelium was observed. However, there was a 7:1 ratio in regard to the muscularis layer at 4 hours. CONCLUSIONS: According to the results of this study a difference in PpIX accumulation in urothelial carcinoma or normal urothelium and the muscular layer of the bladder can be achieved by each route of ALA administration. Although intravesical installation provided tumor and normal urothelium labeling comparable to the intravenous route, it lost the selectivity of PpIX accumulation in tumor and normal urothelium. The effect of this finding on clinical therapy results remains to be resolved in the future.     

Intravesical chemotherapy: studies on the relationship between osmolality and cytotoxicity

The effectiveness of intravesical chemotherapy for the treatment of superficial bladder cancer may be influenced by the conditions of administration, such as the osmotic strength of the instillate. Urine from patients with bladder cancer before treatment had osmolalities in the range 187 to 852 mOsm./kg. and these had decreased by an average of 135 mOsm./kg. at the completion of intravesical chemotherapy. Clinical preparations of drugs used for intravesical chemotherapy had osmotic strengths ranging from 65 to 1,038 mOsm./kg. The antitumor activities of the drugs most frequently used intravesically (doxorubicin, epodyl, mitomycin C and thiotepa), and of cisplatin and epirubicin in media of 6 different osmolalities were measured with a human bladder cancer cell line by inhibition of colony-forming ability. Reducing osmotic strength from 590 to 125 mOsm./kg. significantly increased the in vitro cytotoxicities of thiotepa, mitomycin C, cisplatin and epirubicin but not those of doxorubicin and epodyl. We conclude that the use of an instillate at the lowest achievable osmotic strength probably will be optimal for the intravesical administration of chemotherapeutic drugs.     

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.     

EFFECT OF TACHYKININ NK2 RECEPTOR BLOCKADE ON DETRUSOR HYPERREFLEXIA INDUCED BY BACTERIAL TOXIN IN RATS

Purpose

To see whether a recently characterized model of bacterial toxin-induced urinary bladder inflammation (Stein et al., J. Urol., 155, 1133-1138, 1996). is associated with detrusor hyperreflexia, and whether endogenous tachykinins acting through NK₂ or NK₁ receptors were involved in this model.

Materials and Methods

The bladder or urethane-anesthetized male Wistar rats was cannulated through the dome. Intravesical administration of protamine sulfate (PS, 10 mg./ml./rat) or vehicle for 1 hour was followed by the intravesical administration of E. coli lipopolysaccharide (LPS 1 mg./ml./rat) or vehicle for 1 hour. Cystometries (50 micro l./min.) were performed 3.5 hours after the exposure to LPS. MEN 11,420, a peptide tachykinin NK₂ receptor antagonist, was administered before cystometries or, in a separate group of animals, during cystometries. The effect of SR 140,333, a non-peptide NK₁ receptor antagonist, was also assessed in the presence or absence of MEN 11,420. The urodynamic effects of PS + LPS were also tested in capsaicin-pretreated rats.

Results

Unlike PS or LPS alone, the intravesical administration of PS + LPS induced detrusor hyperreflexia. In PS + LPS treated animals during nonstop cystometries, the intermicturition interval was decreased by about 50% as compared to vehicle-pretreated rats. A quantitatively similar reduction in the bladder capacity was also observed. MEN 11,420 (100 nmol./kg., i.v.) restored the intermicturition interval in PS + LPS-pretreated rats at the level of controls by increasing the bladder capacity, whereas it had no effect in vehicle-pretreated rats. SR 140,333 (1 micro mol./kg., i.v.) neither modified urodynamic parameters in controls and in PS + LPS-treated rats nor altered the effect of MEN 11,420 in these groups. Capsaicin pretreatment (164 micro mol./kg., s.c., 4-5 days before) induced a two-fold increase of the bladder capacity in control rats and prevented PS + LPS-induced bladder hyperreflexia.

Conclusions

The intravesical administration of PS + LPS produces the activation of capsaicin-sensitive afferents. Endogenous tachykinins released from these fibers act through NK₂ receptors to induce detrusor hyperreflexia.     

Peroxynitrite may be involved in bladder damage caused by cyclophosphamide in rats

PURPOSE: It was previously shown that nitric oxide (NO) produced by inducible NO synthase (iNOS) is responsible for cyclophosphamide (CP) induced cystitis. In this study we evaluated whether peroxynitrite is also responsible for CP induced bladder damage in rats. MATERIALS AND METHODS: A total of 38 male albino Wistar rats were divided into 4 groups. Group 1 served as controls and was given 2 ml saline, while 3 groups received a single dose of CP (200 mg/kg) at the same intervals. Group 2 received CP only, group 3 received the selective iNOS inhibitor aminoguanidine (AG) (100 mg/kg) and group 4 received the peroxynitrite scavenger ebselen (2-phenyl-1,2-benzisoselenazol-3[2H]-one) (20 mg/kg). RESULTS: CP injection resulted in severe cystitis with continuous macroscopic hemorrhage, strong edema, inflammation and ulceration. Moreover, bladder tissue malondialdehyde levels, iNOS activation and urine nitrite-nitrate levels were dramatically increased. AG histologically protected bladder against CP damage and decreased urine nitrite-nitrate levels, bladder malondialdehyde and iNOS induction. Ebselen showed results similar to those of AG without changing the urinary nitrite-nitrate level and iNOS activity. CONCLUSIONS: These results suggest that not only nitric oxide, but also peroxynitrite may be important in the pathogenesis of CP induced cystitis.     

Intravesical adenosine triphosphate stimulates the micturition reflex in awake,freely moving rats

PURPOSE: Adenosine triphosphate (ATP) (Sigma Chemical Co., St. Louis, Missouri) is known to contract animal as well as human detrusor muscle and recent investigations have shown an involvement of ligand gated purinergic-1 receptors in detrusor contraction. In addition, ligand gated purinergic-3 receptors have been demonstrated on suburothelial sensory nerves (C-fibers) and may be involved in distention induced initiation of the micturition reflex. We tested the hypothesis that ATP given intravesically can stimulate afferent nerves and initiate the micturition reflex. MATERIALS AND METHODS: Continuous cystometry was performed in conscious, freely moving, normal female Sprague-Dawley rats. Cystometric parameters were evaluated before and after drug administration. RESULTS: Instilled intravesically ATP (10 mM.) induced bladder overactivity in 6 animals with a mean increase in voiding pressure plus or minus standard error of 73 +/- 9 to 107 +/- 9 cm. water (p <0.01), mean baseline pressure increase of 5.32 +/- 0.58 to 12.71 +/- 1.01 cm. water (p <0.01) and mean bladder capacity decrease of 1.13 +/- 0.25 to 0.75 +/- 021 ml. (p <0.01). Lower concentrations had no significant effect. The effects of ATP were abolished by pretreatment with the ganglion blocker hexamethonium (40 mg./kg. ), nitric oxide synthase substrate L-arginine (Sigma Chemical Co.) (200 mg./kg. ) and neurokinin-2 receptor antagonist 123 (S)-N-methyl-N 123 4-(acetylamino-4-phenyl piperidone)-2-(3,4-dichlorophenyl) butyl 125 benzamide (Molecular Probes, Leiden, The Netherlands) (4 nmol.) given intravenously, the ligand gated purinergic-3 antagonist 2'-(or 3')-O-(trinitrophyl)adenosine 5'-triphosphate (50 microM./kg.) given intravenously and the k channel opener ZD6169 given intravesically.(ATP). CONCLUSIONS: ATP given intravesically can induce bladder overactivity, probably by stimulating suburothelial C-fibers. The data suggest that several mediators and mechanisms are involved in mechano-afferent transduction in the bladder.     

Cyclophosphamide-induced hemorrhagic cystitis in rats that underwent colocystoplasty: experimental study

PURPOSE: Cyclophosphamide and its derivatives induce hemorrhagic cystitis. A substantial number of patients receive bladder augmentation or replacements using bowel. If patients who have undergone colocystoplasty need treatment with cyclophosphamide before or after the operation, does hemorrhagic cystitis develop? We evaluated the histological changes produced in the colon wall and bladder related to cyclophosphamide and its derivatives in rats that underwent colocystoplasty. MATERIALS AND METHODS: Sprague-Dawley rats of each sex were grouped according to whether they received a single 200 mg./kg. dose of cyclophosphamide, underwent colocystoplasty, underwent each technique or served as controls. The technique of colocystoplasty was the same in all groups. Results were analyzed according to previously reported criteria, by the gross appearance of the bladder and colon segment used for colocystoplasty, and by histological changes. RESULTS: Two weeks after surgery colocystoplasty had not resulted in secondary changes in the implanted colon segment or original bladder, while there were only nonspecific changes of an inflammatory type in the anastomotic area. After cyclophosphamide administration the animals lost considerable weight and in the bladder area we observed hemorrhagic cystitis that was greater in males than in females, and greater in isolated bladder than when the bladder was sutured to the colon segment. In the colon there was no inflammation or hemorrhage damage of the hemorrhagic cystitis type in the bladder. A total of 12 days after colocystoplasty there were no secondary histological changes except in the anastomotic area. A single 200 mg./kg. dose of cyclophosphamide caused substantial weight loss and hemorrhagic cystitis. Cystitis was quantitatively greater in males than in females and greater in isolated bladder than in bladder anastomosed to the colon. CONCLUSIONS: Administering a single dose of cyclophosphamide did not result in lesions in the colon segment used for colocystoplasty analogous to those of the bladder, such as hemorrhagic cystitis.     

Acute acrolein-induced cystitis in mice

OBJECTIVE: To develop a method of direct intravesical administration of acrolein and evaluate the severity of cystitis in response to increasing doses of acrolein in female C57BL/6N (C57) mice, with further studies to compare the severity of acute acrolein-induced cystitis among C57, C3H/HeJ (HeJ), and C3H/OuJ (OuJ) strains of mice, as chemical cystitis produced by the systemic administration of cyclophosphamide is thought to result from renal excretion of hepatic metabolites, particularly acrolein. MATERIALS AND METHODS: Doses of acrolein (0-1000 microg, 15 microL total volume) were instilled into the bladders of C57 female mice; the bladders were removed 4 or 24 h later, weighed, and processed for histology. Acrolein (6 or 10 microg; 15 microL) was instilled into the bladders of C57, HeJ and OuJ female mice, the bladders removed 4 or 24 h later, weighed, and processed for standard histology and immunohistochemical detection of uroplakin. RESULTS: Increasing doses of acrolein up to 100-200 microg caused a linear increase in bladder weight and greater histological evidence of inflammation. Doses of >200 microg caused submaximal increases in bladder weight, apparently due to structural damage of the bladder. Bladder weight and submucosal oedema were consistently greater in C57 and HeJ than OuJ mice. Treatment with acrolein caused loss of urothelium along with uroplakin in some areas of all bladder sections 4 h after treatment. Bladders from C57 mice had some loss of urothelium 24 h after instillation of 6 or 10 microg acrolein, but urothelium and uroplakin covered nearly all the surface of bladders of HeJ and OuJ mice 24 h after treatment. There were significantly more white blood cells in bladders from C57 or HeJ mice than in bladders from OuJ mice 24 h after an instillation of 6 or 10 microg acrolein. CONCLUSIONS: Intravesical instillation of acrolein produces dose-dependent cystitis in mice. OuJ mice appear relatively more resistant to irritant effects of intravesical acrolein than C57 or HeJ mice, and future studies will be directed at identifying genetic causes for these differences.     

Effects of the nuclear factor-kappaB inhibitors 2-hydroxy-4-trifluoromethylbenzoic acid and aspirin on micturition in rats with normal and inflamed bladder

PURPOSE: We examined the effects of intravenous administration of the 2 nuclear factor-kappaB inhibitors aspirin and 2-hydroxy-4-trifluoromethylbenzoic acid (HTB) on bladder filling and voiding in anesthetized and conscious rats. MATERIALS AND METHODS: Disappearance of isovolumic bladder contractions after intravenous administration of different doses of aspirin and HTB in anesthetized, transurethrally catheterized rats was evaluated. Cystometry was performed in conscious rats during bladder infusion with saline or diluted acetic acid as well as in those with cyclophosphamide induced cystitis. Changes in bladder capacity and voiding pressure were evaluated after intravenous administration of test compounds. RESULTS: Aspirin induced a dose dependent disappearance of isovolumic bladder contractions in anesthetized rats with an extrapolated dose of 2.1 mg./kg. inducing 10 minutes of bladder quiescence. HTB was practically inactive, inducing a dose independent block of 3 to 4 minutes after intravenous administration of 1 to 10 mg./kg. In conscious rats with a bladder infused with saline aspirin was poorly active on bladder capacity, inducing a 20% increase 60 minutes after intravenous administration of 30 and 100 mg./kg. In rats with a bladder infused with acetic acid aspirin was much more active when injected at the initiation of inflammation and after 1 hour of irritant infusion. In this latter situation aspirin increased bladder capacity up to 60% after intravenous administration of 30 and 100 mg./kg. Similar results were obtained in rats with cyclophosphamide induced cystitis in which the bladder was infused with saline. In these cystometrography models 30 mg./kg. HTB intravenously was completely inactive. CONCLUSIONS: The results show that HTB is devoid of significant effects on the micturition reflex in the absence or presence of bladder inflammation, suggesting that acute inhibition of nuclear factor-kappaB does not influence bladder urodynamics in rats. In contrast, aspirin, which is a cyclooxygenase and nuclear factor-kappaB inhibitor, was always effective, indicating the important role of cyclooxygenase enzymes.     

Role of neurokinin receptors in the behavioral effect of intravesical antigen infusion in guinea pig bladder

PURPOSE: To characterize a guinea pig behavior model of bladder pain due to intravesical antigen infusion and to determine the role of neurokinin receptor subtypes in mediating this behavior. MATERIALS AND METHODS: The influence of subtype-selective neurokinin receptor antagonists on increased abdominal licking behavior in response to intravesical antigen infusion in guinea pigs immunized with ovalbumin (OA) was determined. RESULTS: Intravesical OA infusion for 30 minutes induced a significantly greater frequency (about 3-fold) of abdominal licking behavior than during either the 30 minutes pre-challenge or post challenge saline infusions. Treatment with IP capsaicin 7 to 10 days before OA challenge abolished the intravesical antigen-induced behavior. IP injection of the NK1 receptor antagonist CP 99994 (10 mg./kg. or 30 mg./kg.), 30 minutes pretreatment, inhibited the increase in the average number of abdominal licks during antigen infusion. The 30 mg./kg., but not the 10 mg./kg. dose increased the percent of animals showing antinociceptive activity (defined as 4 or less abdominal licks during the antigen infusion). The NK2 receptor antagonist SR 48968 reduced the antigen-induced abdominal licking behavior at IP doses of 3 and 10 mg./kg. but was ineffective at 1 mg./kg. The NK3 receptor antagonist SB 235375 (30 mg./kg., IP) did not reduce this behavior. CONCLUSIONS: These results suggest a role for activation of NK1 and NK2, but not NK3 receptors, by tachykinins released from capsaicin-sensitive nerves, in the increased abdominal licking behavior response of guinea pigs to intravesical antigen infusion.     

The role of bladder afferent pathways in bladder hyperactivity induced by the intravesical administration of nerve growth factor

PURPOSE: Interstitial cystitis, a chronic disease of the bladder, is characterized by urinary frequency, urgency and suprapubic pain. Nerve growth factor is a substance that may sensitize afferent nerves and induce bladder hyperactivity. It is often increased in the urine of patients with interstitial cystitis. We evaluated the role of Adelta and C fiber afferents in the type of bladder hyperactivity induced by the intravesical administration of nerve growth factor. MATERIALS AND METHODS: A total of 22 Wistar and 8 Sprague-Dawley adult female rats were anesthetized with 1.2 gm/kg urethane given subcutaneously. A transurethral catheter was inserted into the bladder. Some animals were pretreated with 125 mg/kg capsaicin injected subcutaneously 4 days before nerve growth factor administration. Cystometry was performed by slowly filling the bladder at a rate of 0.04 ml per minute for 15 minutes with a volume of up to 0.6 ml. Parameters measured included volume threshold and pressure threshold for inducing the micturition reflex, compliance, bladder contraction amplitude, number of contractions and the inter-contraction interval. Nerve growth factor (0.5 ml of 20 microg/ml in 10% dimethyl sulfoxide) or a vehicle solution (0.5 ml of 10% dimethyl sulfoxide) was infused into the bladder through a transurethral catheter and retained for 1 hour. RESULTS: In Wistar rats nerve growth factor increased the mean number of contractions by 111% versus controls (5.7 versus 2.7, p <0.05), and decreased the mean volume threshold by 41% (0.244 versus 0.412 ml, p <0.05). This effect of nerve growth factor was not detected in Sprague-Dawley rats. Capsaicin pretreatment increased the volume threshold by 59% but did not change nerve growth factor induced bladder hyperactivity. CONCLUSIONS: The intravesical application of nerve growth factor acutely induced bladder hyperactivity in Wistar but not in Sprague-Dawley rats. Because the C fiber afferent neurotoxin capsaicin did not change the effect of nerve growth factor, we believe that Adelta afferent neurons have a major role in nerve growth factor induced bladder hyperactivity.