Electroacupuncture Rebalances Autonomic Nervous Activities Decreasing Blood Pressure in Salt-Sensitive Hypertensive Rats

• DOI: 10.1152/physiol.2024.39.s1.716
• Publication Date: 2024-05-21T14:57:50Z
• Authors: Yiwei Gong; Liang-Wu Fu; Stephanie Tjen-A-...; Anh Nguyen; Zhi-Ling Guo; Shaista Malik
• Keywords: 0301 basic medicine; 03 medical and health sciences

High blood pressure (BP) associated with sympathetic overactivity is observed in hypertensive animals and patients. We have recently reported that electroacupuncture (EA) at two sets of acupoints ST36-37 and SP6-7 attenuates BP in Dahl salt-sensitive hypertensive (DSSH) rats through a positive interaction between sympathetic nerve activity inhibition (sympathoinhibition, SI-EA) and anti-inflammation (AI-EA). Chronic inflammation is not only influenced by sympathetic (SNA) but also by parasympathetic nerve activity (PNA). However, it remains unclear if combined SI-EA + AI-EA (cEA) rebalances autonomic nerve activity by both inhibiting SNA and exciting PNA that alleviate hypertension (HTN). We hypothesized that cEA decreased SNA and increased PNA in DSSH rats. Dahl salt-sensitive (DSS) rats were fed 4% salt diet and randomly allocated into two groups: cEA or Sham-EA (no electrical stimulation). Another group of DSS rats studied as normotensive (NTNive) controls were fed a standard rat chow throughout the experiment. Systolic/diastolic BP (SBP/DBP) were measured with Tail-cuff via CODA system once a week. Once DSSH rats developed moderate HTN (SBP 160±5 mmHg), cEA or Sham-EA was applied twice weekly for five weeks, while the NTNive control groups received five weeks of similar study procedures (restraining) without the intervention. After five weeks of treatments, rats were anesthetized for the neuronal recording of SNA and PNA. Cervical vagal nerve (CVN) or splanchnic sympathetic nerve (SSN) was isolated from surrounding connective tissue under a dissecting microscope. Multiple-unit nerve activities were recorded and analyzed with Spike2 software. We observed that SBP (189.2±3.5 mmHg) and DBP (138.6±2.2 mmHg) in Sham-EA treated DSSH rats were higher than SBP (140.8±1.8 mmHg) by 25.6% and DBP (105.5±1.4 mmHg) by 23.9% in rats treated with repetitive cEA. Throughout the study, SBP (132.7±1.8 to 135.2±2.1 mmHg) and DBP (74.1±1.7 to 82.9±2.6 mmHg) in NTNive rats remained within normal range. Furthermore, activity of SSN was significantly greater in Sham-EA treated DSSH rats (23.1±1.6 imp/s) compared to cEA treated rats (15.2±2.0 imp/s, P=0.043) and NTNive rats (11.5 ±0.8 imp/s, P=0.004). Activity of CVN was higher in DSSH rats treated with cEA (27.8±2.9 imp/s) than Sham-EA (12.5±2.3 imp/s, P=0.016). Relative to Sham-EA, activity of CVN was higher (42.5±2.9 imp/s, P=0.001) in normal rats. In conclusion, cEA treatment effectively alleviates hypertension by restoring the balance of autonomic nervous functions through sympathoinhibition and parasympathoexcitation. Funding: NIH 1RO1AT011306-01A1. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.