Regulating autonomic nervous system homeostasis improves pulmonary function in rabbits with acute lung injury

Abstract

BackgroundThis study aimed to investigate the effects of regulating autonomic nervous system (ANS) homeostasis by inhibiting sympathetic hyperactivity and/or enhancing parasympathetic activity on pulmonary inflammation and functional disturbance.MethodsAn animal model of acute lung injury (ALI) was established in rabbits by an intratracheal injection of hydrochloric acid (HCl) in rabbits. Animals in control groups were received saline or HCl only, and the others received both HCl and followed treatments: vagus nerve stimulation (VNS), intravenous injection of tetrahydroaminoacridine (THA), or stellate ganglion block (SGB). The effects of different treatments on the changes in autonomic nervous system homeostasis, pulmonary and systemic inflammation, and functional disturbance were detected.ResultsSympathetic nervous activity was higher than parasympathetic nervous activity in rabbits after HCl aspiration, as demonstrated by the significant changes in the discharge frequency of cervical sympathetic/vagus trunk, and heart rate variability. VNS, THA and SGB could significantly alleviate the changes of ANS induced by HCl aspiration and improved the pulmonary function, especially for SGB treatment.ConclusionsThe disturbance of ANS homeostasis is attributed to a predominance of SNS activity. Administration of VNS, THA and SGB are capable to regulate disequilibrium of the ANS in rabbits with HCl-induced ALI and SGB is supposed to be the most effective approach.

Non-invasive Auricular Vagus Nerve Stimulation as a Potential Treatment for Covid19-Originated Acute Respiratory Distress Syndrome

“…VNS protected against Mesobuthus tamulus venom-induced ARDS in rats, improving parameters like respiratory alterations, hypoxemia, pulmonary edema and histopathological changes (Akella and Deshpande, 2015 ). It attenuated acute lung injury following burn via the anti-inflammatory pathways (Krzyzaniak et al, 2011 ) and improved the pulmonary function of acute lung injury while counterbalancing the predominance of the sympathetic nervous system (Liu et al, 2017 ). VNS was effective to limit pulmonary dendritic cells recruitment within the lung and prevented acute lung injury after burn injury (Lowry et al, 2014 ).…”

“…Our hypotheses on the therapeutic effects of VNS-induced parasympathetic activity are supported by a wide range of state-of-the-art clinical and experimental data: decrease of pro-inflammatory cytokines and modulation of lung injuries by activation of the anti-inflammatory pathways, improvement of pulmonary and cardiac functions by adjusting the sympatho-vagal imbalance, etc. (Dos Santos et al, 2011 ; Krzyzaniak et al, 2011 ; Kessler et al, 2012 ; Kox et al, 2012 ; Levy et al, 2012 ; Reys et al, 2013 ; Tarras et al, 2013 ; Shinlapawittayatorn et al, 2014 ; Akella and Deshpande, 2015 ; Chen et al, 2016 ; Stavrakis and Po, 2016 ; Liu et al, 2017 ; Huang et al, 2019 ).…”

“…In Covid-19, hyperactivity of the sympathetic nervous system may provoke excessive plasma epinephrine and norepinephrine release that lead to pulmonary vasoconstriction and capillary hyperpermeability (see Discussion of Poulat and Couture, 1998 ; Busl and Bleck, 2015 ; Liu et al, 2017 ). At this point an excitatory loop is created in favor to the sympathetic system that provokes an exponential worsening of the symptoms.…”

“…At this point an excitatory loop is created in favor to the sympathetic system that provokes an exponential worsening of the symptoms. That is, the acute lung injury provokes a further imbalance in favor to the sympathetic system, with significant plasma IL-6 and IL-10 increases accompanied by considerable hemorrhage, edema, consolidation, atelectasis, neutrophil infiltration, swelling of type I alveolar epithelial and microvascular endothelial cells, mitochondria cavitation, reduction of the mitochondrial crest, vacuolation of the laminar body of type II alveolar epithelial cells, detachment of microvilli, and rarefaction of the basilar membrane (Liu et al, 2017 ).…”

Targeting the cholinergic anti-inflammatory pathway with vagus nerve stimulation in patients with Covid-19?

“…The lung tissue expresses the cholinergic system including nAChRs involved in the pulmonary parasympathetic inflammatory reflex (Yang et al 2014 ). VNS is capable to regulate disequilibrium of the autonomic nervous system (high sympathetic nervous activity and low parasympathetic nervous activity) in an experimental model of acute lung injury (Liu et al 2017 ) and acts through the CAP, by means of α7nAChR to prevent lung injury (Tarras et al 2013 ). VNS alleviated lung injury through the reduction of gut and lung permeability through nAChR.…”