Objective: To investigate the role of mast cells in chronic prostatitis / chronic pelvic pain syndrome (CP/CPPS).
Methods: Forty-five male SD rats were equally randomized into a control, an experimental autoimmune prostatitis (EAP) model, and an intervention group. The EAP model was made in the latter two groups by subcutaneous injection of mixed suspension of complete Freund's adjuvant and prostate tissue, while the controls were treated subcutaneously with 0.9% sodium chloride. Tactile allodynia was quantified in the pelvic region of the control and EAP animals using Von-Frey filaments at 5, 10, 20, 30 and 40 days. After successful establishment of the EAP model, the rats of the intervention group were injected intraperitonieally with cromolyn sodium for 10 days, and meanwhile tactile allodynia was detected in the rats of the intervention and EAP model groups every other day. Then the prostates of the rats were harvested for HE and toluidine blue staining and measurement of the expression of mast cell tryptase by immunohistochemistry and Western blot.
Results: Von-Frey assessment showed a more severe pelvic pain in the EAP model than in the control rats, but milder in the intervention group than in the EAP models. HE staining revealed infiltration of lymphocytes and neutrophils in the prostate and congestion surrounding the gland in the EAP model rats, but none in the controls. However, both the infiltration and congestion were significantly alleviated in the intervention group. Toluidine blue staining shown that. Compared with the control group, the total count of mast cells and the number degranulated mast cells were markedly increased in the EAP models (P <0.01) but decreased in the intervention group (P <0.05). Both immunohistochemistry and Western blot manifested that the expression of tryptase in the mast cells was remarkably upregulated in the EAP (both P <0.01) but down-regulated in the intervention group (P <0.05 and P <0.01).
Conclusions: Both the total count of mast cells and the number of degranulated mast cells are significantly increased in the prostate of EAP rats. Mast cells are one of the most important mediators of type Ⅲ prostatitis-induced chronic pelvic pain, which can be used as a target for the intervention and treatment of type Ⅲ prostatitis.
目的: 探讨前列腺组织中的肥大细胞在Ⅲ型前列腺炎（CP/CPPS）中的作用。方法: 选取雄性SD大鼠45只，分为对照组（0.9% NaCl盆腔区域及双侧肩胛皮下多点注射）、自身免疫性前列腺炎(EAP)模型组（完全弗氏佐剂与前列腺组织混合悬液盆腔区域及双侧肩胛皮下多点注射）、干预组（EAP模型组基础上加入肥大细胞类胰蛋白酶脱落抑制剂色甘酸钠），每组15只。建立EAP模型过程中，用Von-Frey测痛纤维在第5、10、20、30、40天对对照组、EAP组进行骨盆区域痛觉测试。建模成功后，干预组予色甘酸钠连续腹腔内注射10 d，每两天对其及EAP组进行痛觉测试。选取3组大鼠的前列腺，进行HE染色及甲苯胺蓝染色病理学检查；并通过免疫组化和Western印迹法检测肥大细胞类胰蛋白酶的表达。结果： Von-Frey测痛结果显示：EAP模型组大鼠骨盆疼痛表现较对照组明显，干预组大鼠骨盆疼痛表现较EAP组减轻。HE染色提示：EAP组大鼠前列腺间质内淋巴细胞和中性粒细胞浸润，腺体周围充血。对照组未见明显炎症细胞浸润。与EAP组对比，干预组腺体充血及炎症细胞浸润情况较之减轻。甲苯胺蓝染色提示：EAP组大鼠的前列腺组织中，肥大细胞总数及脱颗粒的肥大细胞数目较对照组增加(P <0.01)，干预组较EAP组减少(P <0.05)。免疫组化染色提示：EAP组大鼠的前列腺组织中，肥大细胞类胰蛋白酶较对照组表达增加（主要表达于细胞核和细胞质中）(P <0.01)，干预组较EAP组减少(P <0.05)。Western印迹提示：EAP组大鼠的前列腺组织中，肥大细胞类胰蛋白酶较对照组表达增加(P <0.01)，干预组较EAP组减少(P <0.01)。结论： EAP大鼠前列腺组织中肥大细胞的总数及脱颗粒的肥大细胞数目增加，肥大细胞是导致Ⅲ型前列腺炎骨盆区域疼痛介质之一，可作为干预及治疗Ⅲ型前列腺炎中一个靶向指标。.
Keywords: Von-Frey; chronic pelvic pain; cromolyn sodium; mast cells; chronic prostatitis / chronic prostatitis.