Adrenal sympathetic nerve mediated the anti‐inflammatory effect of electroacupuncture at ST25 acupoint in a rat model of sepsis

Abstract

Acupuncture plays a vital anti‐inflammatory action in sepsis by activating autonomic nerve anti‐inflammatory pathways, such as sympathoadrenal medullary pathway, but the mechanism remains unclear. This study aims to explore the optimum parameter of electroacupuncture (EA) stimulation in regulating the sympathoadrenal medullary pathway and evaluate EA's anti‐inflammatory effect on sepsis. To determine the optimum parameter of EA at homotopic acupoint on adrenal sympathetic activity, the left adrenal sympathetic nerve firing rate evoked by different intensities of single shock electrical stimulation (ES) at ST25 in healthy male Sprague–Dawley rats were evaluated by in vivo electrophysiological recording, and the levels of norepinephrine (NE) and its metabolites normetanephrine (NMN) were also examined using mass spectrometry. To verify the role of EA at ST25 in sepsis, the rats were given an intraperitoneal injection of lipopolysaccharide (LPS) to induce sepsis model, and survival rate, clinical score, and the level of interleukin (IL)‐6, IL‐1β, and IL‐10 were evaluated after EA application. We observed that 3 mA is the optimal intensity for activating adrenal sympathetic nerve, which significantly elevated the level of NE in the peripheral blood. For LPS‐treated rats, EA at the ST25 apparently increased the survival rate and improved the clinical score compared to the control group. Furthermore, 3 mA EA at ST25 significantly decreased pro‐inflammatory cytokines IL‐6 and IL‐1β and upregulated anti‐inflammatory cytokine IL‐10 compared to the LPS‐treated group. Overall, our data suggested that 3 mA is the optimal EA intensity at ST25 to activate the sympathoadrenal medullary pathway and exert an anti‐inflammatory effect in sepsis.

Electroacupuncture protects the intestinal mucosal barrier in diarrhea-predominant Irritable Bowel Syndrome rats by regulating the MCs/Tryptase/PAR-2/MLCK pathway

“…This is in view of the fact that the superficial nerve innervating the "Tianshu" and "Shangjuxu" points and the intestinal splanchnic nerve are the same ganglion segment (T11-12 and L1-2) [38]. When EA is performed, the peripheral sensory nerve fibers in the dorsal root ganglion (DRG) or trigeminal ganglion are activated, and then the sensory information is transmitted to the spinal cord and brain, thereby activating the peripheral autonomic nerve to achieve an effect on intestinal function and MC degranulation [39].…”

Revealing the biological mechanism of acupuncture in alleviating excessive inflammatory responses and organ damage in sepsis: a systematic review

“…The sympathetic nervous system plays a dual role in regulating inflammatory responses and mediates both proinflammatory and anti-inflammatory effects. A previous study found that stimulating the homosegmental acupoint ST25 with 3 mA EA can drive the release of peripheral NE from the sympathoadrenal medullary axis (108). Unlike low-intensity EA, high-intensity EA activates the sympathetic nervous system and inhibits sepsis-induced inflammation.…”

The immunomodulatory mechanisms for acupuncture practice

“…Meanwhile, Liu et al. and other studies have shown that EA at ST25 can also activate the spinal-sympathetic pathway and have an anti-inflammatory effect ( 104 ). Axons from sympathetic ganglion neurons of the spinal cord enter the adrenal gland and terminate in the cells of the adrenal medulla globular zone, releasing catecholamine and neuropeptide Y (NPY), suggesting a direct sympathetic nervous system of the adrenal medulla.…”