| BACKGROUND AND OBJECTIVE The present detrusor overactivity rat model has several weaknesses. In our study, we improved the model for the establishment and evaluation of detrusor overactivity in female Wistar rats.METHODS We ligated the perineal urethra of female Wistar rats and then performed filling cystometry intra-urethral cannula 6 weeks later. The probability of detrusor overactivity was evaluated. Moreover, bladder capacity, peak voiding pressure and histological changes were investigated.RESULTS Detrusor overactivity ratio of the bladder outlet obstruction group was 32.4%; the control group had no detrusor overactivity. Bladder capacity increased from 0.273±0.036 ml in control group to 0.89±0.19 ml in detrusor overactivity group (P<0.001). Peak voiding pressure increased from 45.9±4.1 cm.H2O in control group to 63.5±17.4 cm.H2O in detrusor overactivity group (P=0.007). For bladder outlet obstruction group, compared to no detrusor overactivity rats, detrusor overactivity rats had higher bladder capacity (0.89±0.19 ml versus 0.43±0.09 ml, P<0.001) and higher peak voiding pressure (63.5±17.4 cm.H20 versus 44.8±6.2 cm.H2O, P=0.005). Detrusor overactivity rats were classified according to peak voiding pressure (49.2±4.2 cm. H2O in group 1 versus 80.8±7.1 cm.H20 in group 2, P<0.001). Moreover, bladder weight increased significantly in detrusor overactivity rats (P=0.003, P=0.028) and detrusor histological hypertrophy was observed.CONCLUSION We established an improved model of detrusor overactivity in female Wistar rats.SIGNIFICANCE Ligating perineal urethra and filling cystometry with intra-urethral cannula approach is a simple and easily reproducible method to establish and evaluate the model of detrusor overactivity rats. BACKGROUND AND OBJECTIVE Some irritable bowel syndrome patients present with detrusor overactivity. In order to study the contribution of irritable bowel syndrome to detrusor overactivity. We investigated the relationship between detrusor overactivity (DO) and visceral hypersensitivity (VH) in rats.METHODS Compared with that of normal rats, afferent nerve receptor (P2X3 receptor) were detected by using immunohistochemical technology and real time RT-PCR in DO rats. Neurotransmitter (substance P) were detected by using immunohistochemical technology in DO rats and normal rats. The sensibility of afferent nerve was evaluated, and the contribution of visceral hypersensitivity to DO was investigated. To investigate the sensitization of spinal cord, the expression of c-Fos positive neurons of cornu posterius medullae spinalis was detected by using immunohistochemical technology, and the contribution of visceral hypersensitivity of spinal cord to DO was assessed. Moreover, the rat model with VH was constructed by injecting chicken egg albumin into the abdominal cavity. After 2 weeks, the filling cystometry was performed to investigate the possibility of DO, and the relationship between VH and DO was established.RESULTS Compared with the control rats, afferent nerve receptor (P2X3 receptor) were detected significantly higher in DO rats by using immunohistochemical technology (P=0.005, P=0.582). Moreover, compared with the control rats, the expression of P2X3 mRNA was detected higher in DO rats by real time RT-PCR (4.96×10-5±2.97×10-5 vs 1.23×10-4±1.06×10-4, P=0.06). In the immunohistochemistry detection, the expression of substance P in DO rats has no significant differences with those in control rats (P>0.05). In the immunohistochemistry detection of dorsal root ganglion, the expression of c-Fos in DO rats was not higher than those in control rats (P>0.05). On the other hand, DO was detected in the VH rats and the control rats. The DO rate was 67% and 0% in the VH rats and control rats, respectively. The bladder capacity, peak voiding pressure and bladder weight of VH rats with DO were significantly higher than those of control rats in the filling cystometry. Compared with the control rats, the bladder capacity of VH rats with DO was higher (0.265±0.052ml vs 0.621±0.185ml, P<0.001). The peak voiding pressure of VH rats with DO was higher the those of the control rats (43.6±5.5cm.H2O vs 50.4±7.0cm.H2O, P=0.014). The bladder weight increased from 0.112±0.021g of the control rats to 0.181±0.034g of VH rats with DO (P<0.001). Moreover, compared with the control rats, intermuscular edema was observed in the VH rats with DO rats. However, no detrusor hypertrophy was found in the VH rats with DO rats.CONCLUSION The afferent nerve receptor (P2X3 receptor) in the DO rats was significantly higher than those in control rats. Therefore, the sensation of bladder was enhanced and irritated in DO rats. Moreover, no higher expression of substance P and c-Fos were observed in the DO rats. On the other hand, DO presented in VH rats. significant differences of filling cystometry and histology were found.SIGNIFICANCE We studied the relationship between DO and VH in rats. We found the contribution of the afferent nerve receptor (P2X3 receptor) to DO. With the unremitting obstructive stimulus, the afferent nerve of bladder was sensitized, and DO was induced. On the other hand, DO was observed in the VH rats. We studied an original view to understand the etiology of VH rats with DO, and changed the status of DO research. BACKGROUND AND OBJECTIVES In the previous study, it's indicated that age is the risk factor for unfavorable clinical characteristics of bladder urothelial tumor. The aim of this study was to investigate the clinical characteristics of bladder urothelial tumors in male and female patients, respectively.PATIENTS AND METHODS We retrospectively reviewed the clinical and pathological data of 356 male patients and 215 female patients with newly diagnosed bladder urothelial tumors were analyzed. Characteristics of different age groups were compared (?50 years,51-69 years, and?70 years). For male patients, the tumor characteristics were analyzed to define the relationship, if any, with benign prostatic hyperplasia/benign prostatic enlargement in male patients. For female patients, the tumor characteristics were analyzed to define the relationship, if any, with menopause. Furthermore, logistic regression model was constructed to discriminate variables.RESULTS For bladder urothelial tumors in male patients, the percentage of carcinoma increased significantly with increasing age (P<0.001), and differences were found among 3 age groups in the distribution of high grade carcinoma (P=0.012). Especially in non-muscle-invasive carcinoma, the percentage of high grade carcinoma increased significantly with increasing age (P=0.006), with significant differences between the?50 years group and the 51-69 years group and?70 years group (P=0.031, P=0.002). Interestingly, compared with non-benign prostatic hyperplasia/benign prostatic enlargement patients, benign prostatic hyperplasia/benign prostatic enlargement patients were more frequently diagnosed with poorly differentiated tumors, and logistic regression confirmed associations between benign prostatic hyperplasia/benign prostatic enlargement and unfavorable carcinoma, controlling for age (P=0.009). For female patients, the percentage of women with bladder urothelial carcinoma increased with increasing age, and a significant difference was observed among the three age groups (P=0.003). Painless macroscopic hematuria occurred more frequently in the group of women 50 years or older at the first presentation (P=0.003). On the other hand, compared with premenopausal women, postmenopausal women were more frequently diagnosed with bladder urothelial carcinoma and had a higher frequency of infiltrating carcinoma (P=0.001 and P=0.011, respectively). Logistic regression confirmed associations between menopause and tumor characteristics, controlling for age.CONCLUSIONS Age is an unfavorable influence on the clinical characteristics of bladder urothelial tumors in male and female patients. For male patients, it was observed that the percentage of unfavorable tumors increased with age. Interestingly, noticeable changes of tumor differentiation appeared at the age of 50 years, and it was indicated that the natural history of carcinoma appeared to differ according to benign prostatic hyperplasia/benign prostatic enlargement statuses. There was a tendency for the men, who were diagnosed with benign prostatic hyperplasia/benign prostatic enlargement, to present with unfavorable carcinoma. For female patients, our study provided evidence that the natural history of bladder urothelial tumors seemed to differ according to menopause. It was observed that the percentage of bladder urothelial carcinomas increased with menopause. Moreover, there was a tendency for postmenopausal women to present with unfavorable infiltrating carcinoma more frequently.SIGNIFICANCE Our study indicated new risk factors for unfavorable BUT in male and female patients. Moreover, our results introduced new research direction for further epidemiological and experimental studies. |
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