College of Acupuncture-moxibustion, Tuina and Rehabilitation, Hunan University of Chinese Medicine, Changsha 410208, China.
Zhen Ci Yan Jiu. 2023 Oct 25;48(10):977-985. doi: 10.13702/j.1000-0607.20230233.
To observe the effect of electroacupuncture (EA) on urodynamics and Raf/MEK/ERK signaling pathway in spine cord tissue of rats after suprasacral spinal cord injury (SSCI), so as to explore its possible mechanism in improving bladder function in rats with detrusor hyperreflexia after SSCI.
Female SD rats were randomly divided into blank, sham operation, model, EA and EA+PD98059 groups, with 12 rats in each group. Thorax (T) 10 spinal cord transection was performed by surgery. Rats in the EA group were given EA (10 Hz/50 Hz, 20 min) at "Ciliao" (BL32), "Zhongji" (CV3), "Sanyinjiao" (SP6) and "Dazhui" (GV14) once daily for 7 d. Rats of the EA+PD98059 group received intraperitoneal injection of PD98059 (5 mg/kg) 2 h before EA intervention. The urodyna-mics was used to measure the base pressure, leak point pressure, maximum pressure, maximum capacity and comp-liance of bladder, and the morphology of bladder detrusor tissue was observed with HE staining. The TUNEL staining was used to detect the cell apoptosis of the spinal cord tissue. The expression levels of exchange protein directly activated by cAMP 2 (Epac2), Rap, phosphorylated rapidly accelerated fibrosarcoma (p-Raf), phosphorylated mitogen-activated extracellular signal-regulated kinase (p-MEK), phosphorylated extracellular signal regulated kinase 1 and 2 (p-ERK1/2), B-cell lymphoma-2 (Bcl-2), and Bcl-2 associated X protein (Bax) were determined by Western blot.
Compared with the sham operation group, the base pressure, leak point pressure and maximum pressure of bladder were significantly increased (<0.01), the maximum bladder capacity and bladder compliance were decreased (<0.01), the cell apoptosis rate of spinal cord tissue was increased (<0.01), and the expression levels of Epac2, Rap, p-Raf, p-MEK, p-ERK1/2, and Bcl-2 protein in spinal cord tissue were decreased (<0.01), while the expression level of Bax protein was increased (<0.01) in the model group. After the treatment and compared with the model group, the base pressure, leak point pressure and maximum pressure of bladder, the cell apoptosis rate of spinal cord tissue, the expression level of Bax protein were decreased (<0.05) in the EA group, while the maximum bladder capacity and bladder compliance, the expression levels of Epac2, Rap, p-Raf, p-MEK, p-ERK1/2, and Bcl-2 protein in spinal cord tissue were all increased (<0.05, <0.01). In comparison with the EA group, the base pressure, leak point pressure and maximum pressure of bladder, the cell apoptosis rate, the expression level of Bax protein were significantly increased (<0.05), whereas the maximum bladder capacity, bladder compliance, and the expression levels of p-MEK, p-ERK1/2, and Bcl-2 protein were decreased (<0.05) in the EA+PD98059 group. Results of HE staining showed disordered transitional epithelial cells and destroyed lamina propria in bladder detrusor tissue, with the infiltration of monocytes in the model group, which was obviously milder in both EA and EA+PD98059 groups, especially in the EA group.
EA can improve the bladder function in detrusor hyperreflexia rats after SSCI, which may be related to its effect in up-regulating Epac2 and Rap, activating the Raf-MEK-ERK pathway, and reducing the cell apoptosis of spinal cord tissue.
观察电针对脊髓完全横断损伤（SSCI）后大鼠尿动力学及脊髓组织中 Raf/MEK/ERK 信号通路的影响，以期探讨其改善 SSCI 后逼尿肌反射亢进大鼠膀胱功能的可能作用机制。
雌性 SD 大鼠随机分为空白组、假手术组、模型组、电针组和电针+PD98059 组，每组 12 只。采用手术方法在 T10 胸段进行脊髓横断。电针组在“次髎”（BL32）、“中极”（CV3）、“三阴交”（SP6）和“大椎”（GV14）给予电针（10 Hz/50 Hz，20 min），每日 1 次，共 7 d。电针+PD98059 组在电针干预前 2 h 腹腔内注射 PD98059（5 mg/kg）。使用尿动力学测量膀胱基础压、漏点压、最大压、最大容量和顺应性，HE 染色观察膀胱逼尿肌组织形态，TUNEL 染色检测脊髓组织细胞凋亡，Western blot 检测交换蛋白直接激活的 cAMP2（Epac2）、Rap、磷酸化快速加速纤维肉瘤（p-Raf）、磷酸化丝裂原激活的细胞外信号调节激酶（p-MEK）、磷酸化细胞外信号调节激酶 1 和 2（p-ERK1/2）、B 细胞淋巴瘤-2（Bcl-2）和 Bcl-2 相关 X 蛋白（Bax）的表达水平。
与假手术组相比，模型组膀胱基础压、漏点压和最大压显著升高（<0.01），最大膀胱容量和膀胱顺应性降低（<0.01），脊髓组织细胞凋亡率增加（<0.01），脊髓组织中 Epac2、Rap、p-Raf、p-MEK、p-ERK1/2 和 Bcl-2 蛋白表达水平降低（<0.01），Bax 蛋白表达水平升高（<0.01）。与模型组比较，电针组和电针+PD98059 组治疗后膀胱基础压、漏点压和最大压、脊髓组织细胞凋亡率、Bax 蛋白表达水平降低（<0.05），电针组和电针+PD98059 组最大膀胱容量和膀胱顺应性、脊髓组织中 Epac2、Rap、p-Raf、p-MEK、p-ERK1/2 和 Bcl-2 蛋白表达水平均升高（<0.05、<0.01）。与电针组比较，电针+PD98059 组膀胱基础压、漏点压和最大压、脊髓组织细胞凋亡率、Bax 蛋白表达水平升高（<0.05），最大膀胱容量和膀胱顺应性、p-MEK、p-ERK1/2 和 Bcl-2 蛋白表达水平降低（<0.05）。HE 染色结果显示，模型组膀胱逼尿肌组织中过渡性上皮细胞排列紊乱，固有层破坏，单核细胞浸润，电针组和电针+PD98059 组均明显减轻，尤其是电针组。
电针可改善 SSCI 后逼尿肌反射亢进大鼠的膀胱功能，其机制可能与上调 Epac2 和 Rap、激活 Raf/MEK/ERK 通路、减少脊髓组织细胞凋亡有关。
