Department of Massage, the First Affiliated Hospital of Tianjin University of Traditional Chinese Medicine/National Clinical Research Center for Acupuncture and Moxibustion of Chinese Medicine, Tianjin 300193, China.
Zhen Ci Yan Jiu. 2023 Oct 25;48(10):969-976. doi: 10.13702/j.1000-0607.20221084.
To observe the therapeutic effect of electroacupuncture (EA) on neurogenic urinary retention rats, so as to explore the underlying mechanism of EA in treating neurogenic urinary retention by focusing on 3-phosphoinositide-dependent protein kinase 1 (PDK1)/protein kinase B (Akt)/hyperpolarization activated cyclic nucleotide-gated cation channel 4 (HCN4) pathway.
Female SD rats were randomly divided into sham operation, model, EA, PDK1 inhibitor, HCN4 blocker and EA + HCN4 blocker groups, with 20 rats in each group. The model of sacral spinal cord injury was established by modified Hassan Shaker spinal cord transection method. EA (2 Hz/15 Hz, 0.5 mA) was applied to "Zhongji" (CV3) and "Zhongliao" (BL33) for 20 min, once daily for 10 days. Rats of the PDK1 inhibitor group received intraperitoneal injection of OSU-03012 (20 mg/kg), and rats of the HCN4 blocker group received intraperitoneal injection of ivabradine (10 mg/kg), both once every other day for 10 days. The urodynamic indexes of rats were detected by multi-channel physiological recorder；muscle strip test was used to detect detrusor excitability；the morphological changes of bladder were observed by HE staining. Immunofluorescence double staining was used to detect the co-expression of HCN4 and C-Kit, a specific marker of interstitial cells of Cajal in bladder. Western blot was used to detect the expression of PDK1/Akt/HCN4 pathway proteins in bladder tissue and heat shock protein 27 (HSP27), a protein related to bladder contraction function.
Compared with the sham operation group, the rats in the model group showed urinary dysfunction, decreased leak point pressure, isolated detrusor spontaneous contraction frequency, fluorescence intensity of C-Kit positive cells, HCN4/C-Kit co-expression, HCN4 and p-HSP27/HSP27 protein expression in bladder tissue (<0.05), and increased maximum bladder capacity and comp-liance, minimum tension during contraction of isolated detrusor, PDK1 and p-Akt/Akt protein expression in bladder tissue (<0.05). Meanwhile, the above index were all reversed after EA and PDK1 inhibitor intervention (<0.05). In comparison with the EA group, the rats had severe urinary dysfunction, the urine leakage point pressure, spontaneous contraction frequency, fluorescence intensity of C-Kit positive cells, the co-expression of HCN4/C-Kit, and the protein expression of HCN4 and p-HSP27/HSP27 were decreased (<0.05), the maximum bladder capacity and compliance, the minimum tension during contraction of isolated detrusor, and the protein expression of PDK1 and p-Akt/Akt in bladder tissue were increased (<0.05) in both HCN4 blocker and EA+HCN4 blocker groups. HE staining showed exfoliated bladder epithelium and disordered layers, vacuolization of bladder wall cells, with infiltration of neutrophils in mucosal and muscular layers in the model group, which were relatively milder in the EA and PDK1 inhibitor groups, but worse in the HCN4 blocker and EA + HCN4 blocker groups.
EA can improve the urinary dysfunction in rats with neurogenic urinary retention, which may be related to its effect in inhibiting the activation of PDK1/Akt pathway, promo-ting HCN4-mediated detrusor excitatory contraction and urinary electrical signal activation.
观察电针对神经原性尿潴留大鼠的治疗作用，探讨电针对神经原性尿潴留的治疗作用机制，重点关注 3-磷酸肌醇依赖性蛋白激酶 1（PDK1）/蛋白激酶 B（Akt）/超极化激活环核苷酸门控阳离子通道 4（HCN4）通路。
雌性 SD 大鼠随机分为假手术组、模型组、电针组、PDK1 抑制剂组、HCN4 阻滞剂组和电针+HCN4 阻滞剂组，每组 20 只。采用改良 Hassan Shaker 脊髓横断法建立骶髓损伤模型。电针（2 Hz/15 Hz，0.5 mA）作用于“中极”（CV3）和“中髎”（BL33）20 min，每日 1 次，共 10 天。PDK1 抑制剂组大鼠腹腔注射 OSU-03012（20 mg/kg），HCN4 阻滞剂组大鼠腹腔注射伊伐布雷定（10 mg/kg），每 2 天 1 次，共 10 天。多道生理记录仪检测大鼠尿动力学指标；肌条试验检测逼尿肌兴奋性；HE 染色观察膀胱形态变化。免疫荧光双染检测膀胱中 HCN4 与 C-Kit（Cajal 间质细胞的特异性标志物）的共表达。Western blot 检测膀胱组织中 PDK1/Akt/HCN4 通路蛋白及热休克蛋白 27（HSP27）的表达，HSP27 与膀胱收缩功能有关。
与假手术组比较，模型组大鼠出现尿失禁，漏尿点压降低，逼尿肌自发性收缩频率、C-Kit 阳性细胞荧光强度、HCN4/C-Kit 共表达、HCN4 和 p-HSP27/HSP27 蛋白表达降低（P<0.05），最大膀胱容量和顺应性增加，逼尿肌分离收缩时的最小张力增加，膀胱组织中 PDK1 和 p-Akt/Akt 蛋白表达增加（P<0.05）。电针和 PDK1 抑制剂干预后，上述指标均逆转（P<0.05）。与电针组比较，HCN4 阻滞剂和电针+HCN4 阻滞剂组大鼠尿失禁严重，漏尿点压、自发性收缩频率、C-Kit 阳性细胞荧光强度、HCN4/C-Kit 共表达、HCN4 和 p-HSP27/HSP27 蛋白表达降低（P<0.05），最大膀胱容量和顺应性增加，逼尿肌分离收缩时的最小张力增加，膀胱组织中 PDK1 和 p-Akt/Akt 蛋白表达增加（P<0.05）。HE 染色显示模型组膀胱上皮脱落，层次紊乱，膀胱壁细胞空泡化，黏膜和肌层有中性粒细胞浸润，电针和 PDK1 抑制剂组较模型组轻，但 HCN4 阻滞剂和电针+HCN4 阻滞剂组更严重。
电针能改善神经原性尿潴留大鼠的尿失禁，其机制可能与抑制 PDK1/Akt 通路激活、促进 HCN4 介导的逼尿肌兴奋收缩和尿电信号激活有关。
