Effect of ovariectomy on bladder mast cells in animal models of interstitial cystitis

Abstract

Objective To investigate the role of female hormones in the pathogenesis of interstitial cystitis by the study of ovariectomy on the bladder mast cells in animal models of interstitial cystitis.Methods A total of 30 female adult Sprague-Dawley rats were divided into 3 groups,including bilateral ovariectomy plus protamine sulfate(OVX + PS) group,sham operation plus protamine sulfate control (Sham +PS) group and control group.The OVX + PS group and Sham + PS group were instilled with 50 g/L protamine sulfate once every two days,and the control group was instilled with normal saline.After intravesical instillation for 60 days,the rats were killed and the bladders were removed for toluidine blue staining to count the number of mast cell and to investigate the form of mast cells.Results In the groups of PS instilled,the bladder mucosa was damaged,and inflammatory cells could be seen in lamina propria.In OVX + PS group,the number of mast cells in lamina propria and detrusor was (2.770 ± 1.112)/HP and (1.180 ±0.598)/HP respectively,and the number was (2.640 ± 1.022)/HP and (0.990 ±0.630)/HP in Sham + PS group.Both of the number were obviously higher than those in control group [(1.160 ± 0.523)/HP and (0.330 ± 0.177)/HP,respectively],and the difference was statistically significant(P ＜ 0.01).However,compared to OVX + PS group and Sham + PS group,the difference was not statistically significant (P ＞ 0.05).the OVX + PS group showed significant lower of the percentage of degranulated mast cells [(27.46 ± 15.69) ％ and (36.93 ± 19.64)％ in lamina propria and detrusor respectively] than those in Sham + PS group [(90.94 ± 8.46)％ and (80.58 ± 24.18)％],and the difference was statistically significant (P＜0.01).Compared to control group [(22.92 ± 9.52) ％ and (24.95 ± 18.81) ％],the percentage of degranulated mast cells in Sham + PS group was obviously higher,and the difference was statistically significant (P ＜0.01).Compared to OVX + PS group and control group,the difference was not statistically significant (P ＞ 0.05) in both lamina propria and detrusor.Conclusion Bilateral ovariectomy could significantly inhibit the degranulated of mast cells in bladder of IC animal models. Key words: Interstitial cystitis ; Mast cells ; Estrogen ; Progestogen ; Ovariectomy ; Rats