Effect of hemodynamic characteristic changes of the carotid artery on 6-OHDA-induced Parkinson's disease model rats treated by Gut-acupuncture

Background: Based on "gut-brain axis" theory, we employed a rat 6-OHDA lesion model to examine the impact of gut-acupuncture on motor symptoms, the abundance of DA neurons in the SN, the hemodynamic characteristics of the carotid artery and SNH. Methods: 6-OHDA-induced PD rats were treated with gut-acupuncture daily, starting day 15 after surgery. Mobility of the limbs was evaluated, abundance of TH + DA neurons in the SN detected, The diameter of carotid arteries and hemodynamic parameters measured by cervical vascular ultrasound CVUS, and TCS utilized to examine SNH. Results: Our data show that gut-acupuncture correlates with significantly increased abundance of TH, a marker of DA neurons compared to untreated rats. Furthermore the area of SNH in the injured side of the acupuncture group was significantly reduced. PSV of LCCA, LICA, RICA showed that were significantly improved i.e. decreased in the acupuncture group, while the diameter of LICA and RCCA in acupuncture group was narrower. We also found that the PSV was significantly increased and the vascular diameter narrowed in LCCA and LICA during treatment, whereas after removing the acupuncture needle the PSV decreased and the vascular diameter widened. Conclusions: Gut-acupuncture can reduce SNH and influence TH abundance in the SN which correlated with changes of hemodynamic characteristics of the lesioned side. We suggest a regulatory mechanism which may affect the vagus nerve through the ENS and cause the change of cervical hemodynamics. It further induces low oxygen tension microenvironment conducive to the proliferation of neural stem cells, which leads to the enrichment of TH in PD model rats of acupuncture group. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of King Saud University.