HRV Study: Electroacupuncture intervention on stress-induced cardiac autonomic imbalance in rats involves corticotropin-releasing hormone
Kristen Sparrow • May 06, 2023
This study looks at stressed out rats (they stress them out by immobilizing them, sad) and use electroacupuncture at PC6 and found that it improved HRV or lowered their physiologic stress. Napadow found similar finding using ear vagal nerve stimulation in rats, (TAVNS) leading to smaller stroke size with stim.
a brief video about the significance of the study is here.
(I have a hard enough time needling PC 6, a very sensitive point, and so I have to needle it with care, but I use it all the time for stress reduction. I don’t have the heart to do electroacupuncture on this point.) I’m very interested in this recent study that showed a way to activate PC 6 with light. This will hopefully lead to new ways to trigger acupuncture points in the future that will work as well but not hurt.
This study investigates the protective role of electroacupuncture at PC6 acupoints in reducing autonomic imbalance that leads to cardiovascular responses in a stress state. The study was conducted on immobilization stress rats and involved ECG recordings for heart rate variability analysis and biological analysis after experiments. The results indicate that electroacupuncture at PC6 ameliorates the enhanced low-frequency band of the power spectrum, the reduced high-frequency band of the power spectrum, and the enhanced LF/HF ratio caused by immobilization stress. The study also found that electroacupuncture at PC6 modulates the CRHergic input in the RVLM and NTS, suggesting its potential use in treating cardiovascular diseases.
Autonomic imbalance is a core aspect of stress response that strongly correlates to cardiovascular diseases. Enhanced activity of the central corticotropin-releasing hormone (CRH) system may result in autonomic imbalance to cause cardiovascular responses in a stress state. Electroacupuncture at PC6 acupoints has been demonstrated to prevent and treat cardiovascular diseases. In this study, we aim to demonstrate the protective role of electroacupuncture at PC6 in ameliorating cardiac autonomic imbalance and investigate the underlying mechanisms in immobilization stress rats. Four groups were subjected. Immobilization stress was applied to three groups. And the rats in two electroacupuncture-intervened groups exerted electroacupuncture at PC6 or tail respectively. Then, we performed ECG recording for heart rate variability (HRV) analysis, and rats were sacrificed after experiments for biological analysis. HRV analysis indicated that electroacupuncture at PC6 improved the enhanced low-frequency band of the power spectrum (LF), the reduced high-frequency band of the power spectrum (HF), and the enhanced LF/HF ratio caused by immobilization stress. Besides, electroacupuncture at PC6 significantly decreased phosphorylated tyrosine hydroxylase expression and increased acetylcholine esterase expression in heart of immobilization stress rats. Furthermore, electroacupuncture at PC6 significantly decreased CRH level and CRH 1 type receptor and CRH 2 type receptor (CRHR2) expressions in the rostral ventrolateral medulla (RVLM), and CRH level and CRHR2 expression in the nucleus of the solitary tract (NTS) of immobilization stress rats. Our findings suggest that electroacupuncture at PC6 can ameliorate stress-induced cardiac autonomic imbalance by modulating the CRHergic input in the RVLM and NTS.