Mechanism of electroacupuncture at Taichong and Quchi points in antagonizing adventitia remodeling of thoracic aorta in stress-induced prehypertension rats

Objective To investigate the mechanism of electroacupuncture at Taichong and Quchi points in antagonizing adventitia remodeling of thoracic aorta in stress-induced prehypertension rats (SIPR).

Methods Foot shock combined with noise stimulation was used to prepare SIPR model. In the electroacupuncture group, Taichong point and Quchi point were selected for intervention, and the blood pressure values of rats in the blank group, model group and electroacupuncture group were measured at different time points, and the change of animal behavior was observed. At the end of 14 d intervention, the samples were taken and the thoracic aortic lesions were detected by hematoxylin eosin staining (HE staining) and Masson staining; reverse transcription polymerase chain reaction (RT-PCR) was used to detect the mRNA expressions of transforming growth factor β₁(TGF-β₁), interleukin-6(IL-6), Smad3 and interleukin-10(IL-10) in thoracic aorta; western blot was used to detect expressions of Smad7, α-smooth muscle activator protein (α-SMA), and typeⅠ and Ⅲ collagen.

Results In the model group, the blood pressure increased and the vascular adventitia was damaged obviously; in the electroacupuncture group, the blood pressure decreased but the adventitia was slightly damaged. Compared with blank group, the mRNA expressions of TGF-β₁, IL-6, IL-10 and Smad3 increased significantly in model group (P<0.05 or P<0.01). Compared with the model group, the mRNA expressions of TGF-β₁, Smad3 and IL-6 decreased significantly in the electroacupuncture group, while the expression of IL-10 mRNA increased significantly (P<0.05 or P<0.01). Compared with the blank group, expressions of type Ⅰand Ⅲ collagen and α-SMA protein increased significantly, and expression of Smad7 protein decreased significantly (P<0.05 or P<0.01). Compared with the model group, expressions of type Ⅰand Ⅲ collagen and α-SMA protein decreased significantly, and expression of Smad7 protein increased significantly (P<0.05 or P<0.01).

Conclusion Electroacupuncture at Taichong and Quchi points can significantly reduce blood pressure in SIPR and effectively prevent vascular adventitia remodeling, and its mechanism may be related to the regulation of TGF-β₁/Smads signaling pathway and alleviation of inflammatory response.