Electroacupuncture Improves Survival in Rats with Lethal Endotoxemia via  the Autonomic Nervous System

Background Recent advances have indicated a complex interplay between the autonomic nervous system and the innate immune system. Targeting neural networks for the treatment of sepsis is being developed as a therapeutic strategy. Because electroacupuncture at select acupoints can modulate activities of the autonomic nervous system, we tested the hypothesis that electroacupuncture at specific acupoints could modulate systemic inflammatory responses and improve survival via its impact on the autonomic nervous system in a rat model of sepsis. Methods Sprague-Dawley male rats received electroacupuncture for 45 min before and at 1, 2, or 4 h after a lethal dose of intraperitoneal lipopolysaccharide injection (6 mg/kg). Outcomes included survival and systemic cytokine responses. Also, the possible roles of neural circuitry, including the hypothalamic-pituitary-adrenal axis and the autonomic nervous system, were evaluated. Results Electroacupuncture pretreatment at the Hegu acupoints significantly attenuate systemic inflammatory responses and improve survival rate from 20% to 80% in rats with lethal endotoxemia. Such a site-specific effect requires the activation of muscarinic receptors in the central nervous system, but not increasing central sympathetic tone. In the periphery synergistic, rather than independent, action of the sympathetic and parasympathetic systems is also necessary. Conclusions Electroacupuncture pretreatment has a dramatic survival-enhancing effect in rats with lethal endotoxemia, which involves the activation of efferent neural circuits of the autonomic nervous system (e.g., cholinergic antiinflammatory pathway). This approach could be developed as a prophylactic treatment for sepsis or perioperative conditions related to excessive inflammation.