Effect Of Ovariectomy On Bladder Mast Cells In Animal Models Of Interstitial Cystitis

Obiective:1. An animal model of Interstitial Cystitis (IC) in rats was developed using intravesical infusion of protamine sulfate (PS).2. To investigate the role of female hormones in the pathogenesis of interstitial cystitis through to study the changes of bladder urothelium and mast cells in animal models of interstitial cystitis after ovariectomy.Materials and Methods:1. subjects:Female Sprague-Dawley rats weighing193-255g (the average242.4g), age6-8week,were used in this study.2. Main reagents and soucreProtamine sulfate Grade X:Sigma Chemical, St. Louis, Mo; serum17β-estradiol Elisa Kit:the IBL Company; seium progesterone Elisa kit:the IBL Company; toluidine blue:Tianjin Institute of Urology.3. MethodsA total of30female adult Sprague-Dawley rats were divided into3groups, including bilateral ovariectomy plus protamine sulfate(OVX+PS) group, sham operation plus protamine sulfate control(SHAM+PS) group and control group(SHAM+NS). To determine the level of serum17β-estradiol and progesterone, and the three groups are instilled with protamine sulfate and normal saline respectively after that the level of17β-estradiol and progesterone are lowest. After intravesical instillation for60days, the rats were killed and the bladders were removed for HE stain,toluidin blue stain and transmission electron microscope.4.Statistical analysisStatistical analysis was carried out using IBM SPSS19.0. Normally distributed data are described with x±s. A comparison between the groups was done using Student’s t test for parametric data. The dates among groups were compared with an analysis of variance (ANOVA). Values of p<0.05were regarded as significant. Resulst:1. After ovariectomy, both of the concentrations of serum17β-estradiol and progesterone were lower in OVX+PS group. The lowest concentrations were found about one month after oparation. Compare with preoperative, SHAM+PS group and the SHAM+NS group, the differences were statistically significant (P<0.05).2. The bladder mucosa of normal control group (SHAM+NS group) has no injury and the lamina propria has no obvious inflammatory cell infiltration, while The bladder mucosa of the groups which were perfused with PS (OVX+PS group and SHAM+PS group) was obviously injured,and the lamina propria has obvious inflammatory cell infiltration.3. Compared with normal control group, the mast cell counts in bladder mucosa lamina propria, detrusor and serosa of OVX+PS group and SHAM+PS group were significantly increased, and the differences were statistically significant (P<0.01). However, compared OVX+PS group and the SHAM+PS group,the mast cell count differences were not statistically significant (P>0.05).4. The percentage of degranulation of mast cells in OVX+PS group and the SHAM+NS group were significantly lower than that in SHAM+PS group in the lamina propria and detrusor (P<0.01), and in serosal the percentage of degranulation of mast cells in OVX+PS group were also significantly lower than that in SHAM+PS group (P<0.01). There were no significant degranulation of mast cells in serosal in the SHAM+NS group. In the lamina propria, the degranulation percentage of mast cells in OVX+PS group was significantly lower than that in SHAM+PS group(P <0.01), while the degranulation percentage of mast cells in the two groups were not statistically significant (P>0.05).5. Transmission electron microscope shows that most of the mast cells within the SHAM+NS group and the OVX+PS group were Unactivated, and the number of degranulation of mast cells was lower than30%. In SHAM+PS group, most of the mast cells were activated, and the number of degranulation of mast cells was more than70%.Conclusions1. A typical IC animal models was developed using intravesical infusion of PS. Through repeated, prolonged PS perfused, the animal model appares bladder wall thicken, mast cell infiltrate significant. These changes are similar to feature of IC, support the conclusion of dysfunction bladder urothelium may play an principal role in pathogenesis of IC.Meanwhile establish the investigative basis for bladder inflammatory disease, especially for Interstitial Cystitis.2. There was no significant effect on the damage of bladder mucosa and the infiltration of mast cells of the female hormones (estrogen and progestin). However, the female hormones can significantly promote the activation of mast cells in the bladder of IC patients. Thus to reduce the content of female hormones in IC patients or to antagonize the role of female hormones may play an active role in the relief of symptom in IC patients. And the estrogen receptor expressed in mast cells can be used as a new therapeutic target of the IC.