2型糖尿病大鼠膀胱逼尿肌中膜结合型前列腺素E_2合酶1的表达及意义

Expression of mPGES-1 in bladder of streptozotocin-induced diabetic rats

目的探讨2型糖尿病大鼠膀胱逼尿肌中膜结合型前列腺素E_2合酶1(m PGES-1)的表达及意义。方法将36只雌性SD大鼠随机分成糖尿病组与对照组,每组18只。使用链脲佐菌素(STZ)建立2型糖尿病大鼠动物模型。造模成功后12周,观察并比较两组大鼠一般生理体征;在光镜下观察膀胱逼尿肌组织HE染色结果,在透射电镜下观察组织超微结构变化,采用免疫组化法检测组织中m PGES-1表达水平,并使用前列腺素E_2(PGE_2)酶联免疫试剂盒检测24h尿液中PGE_2含量,所得结果进行组间比较。结果与对照组比较,糖尿病组大鼠终末体重明显降低(P<0.05),终末血糖、膀胱湿重和24h尿量均明显增加(均P<0.05)。与对照组比较,糖尿病组大鼠在光镜下可见逼尿肌肌束结构排列紊乱,肌束间隙变宽;在透射电镜下可见逼尿肌细胞间距变宽,胞质内线粒体肿胀破裂呈空泡状。糖尿病组大鼠24h尿液PGE_2含量、膀胱逼尿肌组织中m PGES-1表达水平较对照组均明显下降(P<0.05)。结论2型糖尿病大鼠膀胱逼尿肌组织中m PGES-1表达水平及尿液PGE_2含量均明显降低,可能与糖尿病性膀胱病的进展有关。

Objective To investigate the expression of membrane-associated prostaglandin synthase 1 （mPGES-1） in urinary bladder of streptozotocin （STZ）-induced diabetic rats. Methods Thirty six female SD rats were randomly divided into model and control groups with 18 in each. Diabetic cystopathy （DCP） model was induced by intraperitonieal injection of streptozotocin （STZ）. After 12 weeks, the animals were sacrificed and the bladder samples were harvested. The histological changes were observed by light microscopic and electron microscopic examination, and the expression of mPGES-1 in bladder tissue was detected by immunohistochemistry and the contents of PGE2 in 24h urine were measured by ELISA method. Results Compared with the control group, diabetic rats showed disorder of detrusor smooth muscle structure and wider muscle gap under light microscope. Electron microscopy showed that intercellular space of detrusor was wider and detrusor cells was irregular in shape, the swelling and rupture of mitochondria, and vacuolization were found in cytoplasm. Compared to control group, the contents of PGE2 in the urine and the expression of mPGES-1 in bladder detrusor tissue of DCP group were significantly decreased. Conclusion The down-regulated expression of mPGES-1 may play an important role in the occurrence and development of diabetic cystopathy in rats.