Correlation analysis between body mass index and foot length in Chinese adolescents: a regional study.

This study aims to analyse the relationship between body mass index and foot length in Chinese adolescents and to provide theoretical guidance for preventing a flat foot in Chinese adolescents. This study recruited 1477 students aged 14-23 years. The participants' height, weight, and body mass index were measured, as well as baseline data, including age, gender and foot length. Differences in foot length (bilateral) and flat foot distribution were statistically significant except for the normal foot and high arch foot distribution based on different body mass index groups. Linear correlation analysis demonstrated that body height, weight and body mass index were positively correlated with bilateral foot length regardless of gender. Body mass index acted as a risk factor for flat foot (bilateral) through disordered multi-classification logistic regression analysis. Body mass index was positively correlated with left and right foot length regardless of gender and acted as a risk factor for a flat foot in Chinese adolescents. Practitioner summary: Significant differences exist in the anthropometric data of various races and ethnic groups. The study was investigated in the form of a cross-sectional study. BMI was positively correlated with bilateral foot length and acted as a risk factor for a flat foot in Chinese adolescents.

The analgesic effects of ß-elemene in rats with neuropathic pain by inhibition of spinal astrocytic ERK activation.

Neuropathic pain takes a heavy toll on individual well-being, while current therapy is far from desirable. Herein, we assessed the analgesic effect of ß-elemene, a chief component in the traditional Chinese medicine Curcuma wenyujin, and explored the underlying mechanisms at the level of spinal dorsal horn (SDH) under neuropathic pain. A spared nerve injury (SNI)-induced neuropathic pain model was established in rats. Intraperitoneal injection (i.p.) of ß-elemene was administered for 21 consecutive days. Mechanical allodynia was explored by von Frey filaments. The activation of the mitogen-activated protein kinase (MAPK) family (including ERK, p38, and JNK) in spinal neurons, astrocytes, and microglia was evaluated using immunostaining 29 days after SNI surgery. The expression of GFAP, Iba-1, p-ERK, p-JNK, and p-p38 within the SDH was measured using immunoblotting. The levels of proinflammatory cytokines (including TNF-α, IL-1ß, and IL-6) were measured with ELISA. The levels of oxidative stress indicators (including MDA, SOD, and GSH-PX) were detected using biochemical tests. Consecutive i.p. administration of ß-elemene relieved SNI-induced mechanical allodynia (with an EC50 of 16.40 mg/kg). SNI significantly increased the expression of p-ERK in spinal astrocytes but not microglia on day 29. ß-elemene reversed spinal astrocytic ERK activation and subsequent upregulation of proinflammatory cytokines in SNI rats, with no effect on the expression of p38 and JNK in spinal glia. ß-elemene also exerted antioxidative effects by increasing the levels of SOD and GSH-PX and decreasing the level of MDA. Our results suggest that SNI induces robust astrocytic ERK activation within the SDH in the late phase of neuropathic pain. ß-elemene exerts remarkable analgesic effects on neuropathic pain, possibly by inhibiting spinal astrocytic ERK activation and subsequent neuroinflammatory processes. Our findings suggest that ß-elemene might be a promising analgesic for the treatment of chronic pain.

Necroptosis is required for atrial fibrillation and involved in aerobic exercise-conferred cardioprotection.

Necroptosis, a novel programmed cell death, plays a critical role in the development of fibrosis, yet its role in atrial fibrillation (AF) remains elusive. Mounting evidence demonstrates that aerobic exercise improves AF-related symptoms and quality of life. Therefore, we explored the role of necroptosis in AF pathogenesis and exercise-conferred cardioprotection. A mouse AF model was established either by calcium chloride and acetylcholine (CaCl2 -Ach) administration for 3 weeks or high-fat diet (HFD) feeding for 12 weeks, whereas swim training was conducted 60 min/day, for 3-week duration. AF susceptibility, heart morphology and function and atrial fibrosis were assessed by electrophysiological examinations, echocardiography and Masson's trichrome staining, respectively. Both CaCl2 -Ach administration and HFD feeding significantly enhanced AF susceptibility (including frequency and duration of episodes), left atrial enlargement and fibrosis. Moreover, protein levels of necroptotic signaling (receptor-interacting protein kinase 1, receptor-interacting protein kinase 3, mixed lineage kinase domain-like protein and calcium/calmodulin-dependent protein kinase II or their phosphorylated forms) were markedly elevated in the atria of AF mice. However, inhibiting necroptosis with necrostatin-1 partly attenuated CaCl2 -Ach (or HFD)-induced fibrosis and AF susceptibility, implicating necroptosis as contributing to AF pathogenesis. Finally, we found 3-week swim training inhibited necroptotic signaling, consequently decreasing CaCl2 -Ach-induced AF susceptibility and atrial structural remodeling. Our findings identify necroptosis as a novel mechanism in AF pathogenesis and highlight that aerobic exercise may confer benefits on AF via inhibiting cardiac necroptosis.

Association of serum adropin with the presence of atrial fibrillation and atrial remodeling.

OBJECTIVE: Adropin, a newly identified regulatory protein encoded by Enho gene, suppressed tumor necrosis factor α-induced THP1 monocyte adhesion to human umbilical vein endothelial cells. In addition, inflammation is demonstrated to be involved in the mechanism of atrial fibrillation (AF). Atrial remodeling is correlated with the persistence and progression of AF. Adropin is hypothesized to correlated with AF and atrial remodeling. This study aims to determine the correlation of serum adropin and the presence of AF and remodeling. METHODS: This study consisted of 344 AF patients and 210 healthy controls. AF patients were then divided into three subgroups of paroxysmal AF, persistent AF, and permanent AF. Serum adropin concentrations were examined using enzyme-linked immunosorbent assay method. Left atrial diameter (LAD) was measured to evaluate atrial remodeling. RESULTS: Decreased serum adropin concentrations were found in AF patients compared with healthy controls. Logistic regression analysis confirmed that serum adropin was inversely associated with the presence of AF (OR 0.218, 95% CI 0.15-0.316; P < 0.001). Permanent AF patients had significantly reduced serum adropin concentrations compared with persistent and paroxysmal AF patients. There were decreased serum adropin concentrations in persistent AF group than those in paroxysmal AF group. Simple linear regression analyses showed that serum adropin in AF patients were negatively correlated with BMI, SBP, and LAD. Multiple stepwise regression analysis showed that LAD remained to be inversely associated with serum adropin (ß = 0.2, P = 0.010). CONCLUSION: Serum adropin concentrations are inversely correlated with the presence of AF and atrial remodeling.

Electrophysiological Measurement of Rat Atrial Epicardium Using a Novel Stereotaxic Apparatus.

Flexible, in vivo maneuverable electrophysiology mapping techniques are not available in rat models. A novel cardiac stereotactic electrophysiology epicardial mapping system (CREAMS) allows for various measurements, including: (1) recording unipolar electrograms at multiple sites; (2) positioning of mapped sites and precision testing (Distance between the two "centers" = 297 ± 54 µm, n = 15); (3) evaluation of electrophysiology in an in vivo Sprague-Dawley rat model with high-frequency stimulation (HFS)-induced Atrial fibrillation (AF) at high right atrium (HRA) sites. We found that of the right atrium dispersion of effective refractory period (P < 0.05) and the window of vulnerability (P < 0.01) were significantly increased (P < 0.05) after HRA HFS. CREAMS has the potential for convenient electrophysiology assessment in a rat AF model through stereo-positioning, and flexible operating manipulation.

MicroRNA-24-3p Attenuates Myocardial Ischemia/Reperfusion Injury by Suppressing RIPK1 Expression in Mice.

BACKGROUND/AIMS: This study was developed to investigate a potential therapeutic method for myocardial ischemia/reperfusion injury involving the promotion of miR-24-3p expression. METHODS: Microarray analysis was used to screen differentially expressed genes in a myocardial ischemia/reperfusion (I/R) injury mouse model. Gene set enrichment analysis was utilized to determine vital signaling pathways. Targeting verification was conducted with a luciferase reporter assay. Myocardial I/R injury was developed in mice, and the expression levels of RIPK1 and miR-24-3p were investigated by qRT-PCR and Western blot. Hemodynamic parameters and the activity of serum myocardial enzymes were measured to evaluate cardiac function. Infarct area was observed through HE and TTC staining. Myocardial cell apoptosis was examined by TUNEL staining and caspase-3 activity analysis. RESULTS: RIPK1 was an upregulated mRNA found by microarray analysis and a verified target of the downregulated miRNA miR-24-3p. The upregulation of RIPK1 (1.8-fold) and the downregulation of miR-24-3p (0.3-fold) were confirmed in I/R mice. RIPK1 led to impaired cardiac function indexes, increased infarct area and cell apoptosis, while miR-24-3p could reverse the injury by regulating RIPK1. The TNF signaling pathway was proven to be involved in myocardial I/R injury through the detection of the dysregulation of related proteins. CONCLUSION: In conclusion, RIPK1 was upregulated and miR-24-3p was downregulated in a myocardial I/R injury mouse model. RIPK1 could aggravate myocardial I/R injury via the TNF signaling pathway, while miR-24-3p could suppress RIPK1 and therefore exert cardioprotective effects in myocardial I/R injury.

Efficacy and safety of piperacillin-tazobactam compared with meropenem in treating complicated urinary tract infections including acute pyelonephritis due to extended-spectrum ß-lactamase-producing Enterobacteriaceae.

Introduction: Extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae pose a huge threat to human health, especially in the context of complicated urinary tract infections (cUTIs). Carbapenems and piperacillin-tazobactam (PTZ) are two antimicrobial agents commonly used to treat cUTIs. Methods: A monocentric retrospective cohort study focused on the treatment of cUTIs in adults was conducted from January 2019 to November 2021. Patients with a positive urine culture strain yielding ≥ 103 colony-forming units per milliliter (CFU/mL), and sensitive to PTZ and carbapenems, were included. The primary endpoint was clinical success after antibiotic therapy. The secondary endpoint included rehospitalization and 90-day recurrence of cUTIs caused by ESBL-producing Enterobacteriaceae. Results: Of the 195 patients included in this study, 110 were treated with PTZ while 85 were administered meropenem. The rate of clinical cure was similar between the PTZ and meropenem groups (80% vs. 78.8%, p = 0.84). However, the PTZ group had a lower duration of total antibiotic use (6 vs. 9; p < 0.01), lower duration of effective antibiotic therapy (6 vs. 8; p < 0.01), and lower duration of hospitalization (16 vs. 22; p < 0.01). Discussion: In terms of adverse events, the safety of PTZ was higher than that of meropenem in the treatment of cUTIs.

Anterior Cingulate Cortex Mediates Hyperalgesia and Anxiety Induced by Chronic Pancreatitis in Rats.

Central sensitization is essential in maintaining chronic pain induced by chronic pancreatitis (CP), but cortical modulation of painful CP remains elusive. Here, we examined the role of the anterior cingulate cortex (ACC) in the pathogenesis of abdominal hyperalgesia in a rat model of CP induced by intraductal administration of trinitrobenzene sulfonic acid (TNBS). TNBS treatment resulted in long-term abdominal hyperalgesia and anxiety in rats. Morphological data indicated that painful CP induced a significant increase in FOS-expressing neurons in the nucleus tractus solitarii (NTS) and ACC, and some FOS-expressing neurons in the NTS projected to the ACC. In addition, a larger portion of ascending fibers from the NTS innervated pyramidal neurons, the neural subpopulation primarily expressing FOS under the condition of painful CP, rather than GABAergic neurons within the ACC. CP rats showed increased expression of vesicular glutamate transporter 1, and increased membrane trafficking and phosphorylation of the N-methyl-D-aspartate receptor (NMDAR) subunit NR2B and the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) subunit GluR1 within the ACC. Microinjection of NMDAR and AMPAR antagonists into the ACC to block excitatory synaptic transmission significantly attenuated abdominal hyperalgesia in CP rats, which was similar to the analgesic effect of endomorphins injected into the ACC. Specifically inhibiting the excitability of ACC pyramidal cells via chemogenetics reduced both hyperalgesia and comorbid anxiety, whereas activating these neurons via optogenetics failed to aggravate hyperalgesia and anxiety in CP rats. Taken together, these findings provide neurocircuit, biochemical, and behavioral evidence for involvement of the ACC in hyperalgesia and anxiety in CP rats, as well as novel insights into the cortical modulation of painful CP, and highlights the ACC as a potential target for neuromodulatory interventions in the treatment of painful CP.

Glutamatergic synapses from the insular cortex to the basolateral amygdala encode observational pain.

Empathic pain has attracted the interest of a substantial number of researchers studying the social transfer of pain in the sociological, psychological, and neuroscience fields. However, the neural mechanism of empathic pain remains elusive. Here, we establish a long-term observational pain model in mice and find that glutamatergic projection from the insular cortex (IC) to the basolateral amygdala (BLA) is critical for the formation of observational pain. The selective activation or inhibition of the IC-BLA projection pathway strengthens or weakens the intensity of observational pain, respectively. The synaptic molecules are screened, and the upregulated synaptotagmin-2 and RIM3 are identified as key signals in controlling the increased synaptic glutamate transmission from the IC to the BLA. Together, these results reveal the molecular and synaptic mechanisms of a previously unidentified neural pathway that regulates observational pain in mice.

Voltammetric Electrochemical Sensor for Phylogenetic Study in Acer Linn.

Acer Linn. is a highly divergent species morphology in the maple family (Aceraceae). It is one of the genera facing a very difficult taxonomic situation. The phylogeny of the genus and the taxonomic system under the genus remain unclear. The use of electrochemical fingerprints for plant phylogenetic study is an emerging application in biosensors. In this work, leaves of 18 species of Acer Linn. with an exo-taxa were selected for electrochemical fingerprint recording. Two different conditions were used for improving the data abundance. The fingerprint of all species showed a series of oxidation peaks. These peaks can be ascribed to the oxidation of flavonols, phenolic acids, procyanidins, alkaloids, and pigments in plant tissue. These electrochemical fingerprints can be used for the identification of plant species. We also performed a phylogenetic study with data from electrochemical fingerprinting. The phylogenetic tree of Acer is divided into three main clades. The result is in full agreement with A. shangszeense var. anfuense, A. pictum subsp. mono, A. amplum, A. truncatum, and A. miaotaiense, belonging to the subsection Platanoidea. A. nikoense and A. griseum were clustered together in the dendrogram. Another group that fits the traditional classification results is in the subsection Integrifolia.

Enhancing Fatty Acids Oxidation via L-Carnitine Attenuates Obesity-Related Atrial Fibrillation and Structural Remodeling by Activating AMPK Signaling and Alleviating Cardiac Lipotoxicity.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in clinical setting. Its pathogenesis was associated with metabolic disorder, especially defective fatty acids oxidation (FAO). However, whether promoting FAO could prevent AF occurrence and development remains elusive. In this study, we established a mouse model of obesity-related AF through high-fat diet (HFD) feeding, and used l-carnitine (LCA, 150 mg/kg⋅BW/d), an endogenous cofactor of carnitine palmitoyl-transferase-1B (CPT1B; the rate-limiting enzyme of FAO) to investigate whether FAO promotion can attenuate the AF susceptibility in obesity. All mice underwent electrophysiological assessment for atrial vulnerability, and echocardiography, histology and molecular evaluation for AF substrates and underlying mechanisms, which were further validated by pharmacological experiments in vitro. HFD-induced obese mice increased AF vulnerability and exhibited apparent atrial structural remodeling, including left atrial dilation, cardiomyocyte hypertrophy, connexin-43 remodeling and fibrosis. Pathologically, HFD apparently leads to defective cardiac FAO and subsequent lipotoxicity, thereby evoking a set of pathological reactions including oxidative stress, DNA damage, inflammation, and insulin resistance. Enhancing FAO via LCA attenuated lipotoxicity and lipotoxicity-induced pathological changes in the atria of obese mice, resulting in restored structural remodeling and ameliorated AF susceptibility. Mechanistically, LCA activated AMPK/PGC1α signaling both in vivo and in vitro, and pharmacological inhibition of AMPK via Compound C attenuated LCA-induced cardio-protection in palmitate-treated primary atrial cardiomyocytes. Taken together, our results demonstrated that FAO promotion via LCA attenuated obesity-mediated AF and structural remodeling by activating AMPK signaling and alleviating atrial lipotoxicity. Thus, enhancing FAO may be a potential therapeutic target for AF.

Electrochemical Fingerprint Biosensor for Natural Indigo Dye Yielding Plants Analysis.

Indigo is a plant dye that has been used as an important dye by various ancient civilizations throughout history. Today, due to environmental and health concerns, plant indigo is re-entering the market. Strobilanthes cusia (Nees) Kuntze is the most widely used species in China for indigo preparation. However, other species under Strobilanthes have a similar feature. In this work, 12 Strobilanthes spp. were analyzed using electrochemical fingerprinting technology. Depending on their electrochemically active molecules, they can be quickly identified by fingerprinting. In addition, the fingerprint obtained under different conditions can be used to produce scattered patter and heatmap. These patterns make plant identification more convenient. Since the electrochemically active components in plants reflect the differences at the gene level to some extent, the obtained electrochemical fingerprints are further used for the discussion of phylogenetics.

CXCL12/CXCR4 axis as a key mediator in atrial fibrillation via bioinformatics analysis and functional identification.

Atrial fibrillation (AF) is an increasingly prevalent arrhythmia with significant health and socioeconomic impact. The underlying mechanism of AF is still not well understood. In this study, we sought to identify hub genes involved in AF, and explored their functions and underlying mechanisms based on bioinformatics analysis. Five microarray datasets in GEO were used to identify the differentially expressed genes (DEGs) by Robust Rank Aggregation (RRA), and hub genes were screened out using protein-protein interaction (PPI) network. AF model was established using a mixture of acetylcholine and calcium chloride (Ach-CaCl2) by tail vein injection. We totally got 35 robust DEGs that mainly involve in extracellular matrix formation, leukocyte transendothelial migration, and chemokine signaling pathway. Among these DEGs, we identified three hub genes involved in AF, of which CXCL12/CXCR4 axis significantly upregulated in AF patients stands out as one of the most potent targets for AF prevention, and its effect on AF pathogenesis and underlying mechanisms were investigated in vivo subsequently with the specific CXCR4 antagonist AMD3100 (6 mg/kg). Our results demonstrated an elevated transcription and translation of CXCL12/CXCR4 axis in AF patients and mice, accompanied with the anabatic atrial inflammation and fibrosis, thereby providing the substrate for AF maintenance. Blocking its signaling via AMD3100 administration in AF model mice reduced AF inducibility and duration, partly ascribed to decreased atrial inflammation and structural remodeling. Mechanistically, these effects were achieved by reducing the recruitment of CD3+ T lymphocytes and F4/80+ macrophages, and suppressing the hyperactivation of ERK1/2 and AKT/mTOR signaling in atria of AF model mice. In conclusion, this study provides new evidence that antagonizing CXCR4 prevents the development of AF, and suggests that CXCL12/CXCR4 axis may be a potential therapeutic target for AF.

Electrochemical Voltammogram Recording for Identifying Varieties of Ornamental Plants.

An electrochemical voltammogram recording method for plant variety identification is proposed. Electrochemical voltammograms of Vistula, Andromeda, Danuta, Armandii 'Apple Blossom,' Proteus, Hagley Hybrid, Violet Elizabeth, Kiri Te Kanawa, Regina, and Veronica's Choice were recorded using leaf extracts with two solvents under buffer solutions. The voltametric data recorded under different conditions were derived as scatter plots, 2D density patterns, and hot maps for variety identification. In addition, the voltametric data were further used for genetic relationship studies. The dendrogram deduced from the voltammograms was used as evidence for relationship study. The dendrogram deduced from voltametric data suggested the Andromeda, Danuta, Proteus, Regina, and Hagley Hybrid were closely related, while Violet Elizabeth and Veronica's Choice were closely related. In addition, Vistula and Armandii 'Apple Blossom' could be considered outliers among the varieties.

Nucleus tractus solitarius mediates hyperalgesia induced by chronic pancreatitis in rats.

BACKGROUND: Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis (CP). We hypothesized that the nucleus tractus solitarius (NTS), a primary central site that integrates pancreatic afferents apart from the thoracic spinal dorsal horn, plays a key role in the pathogenesis of visceral hypersensitivity in a rat model of CP. AIM: To investigate the role of the NTS in the visceral hypersensitivity induced by chronic pancreatitis. METHODS: CP was induced by the intraductal injection of trinitrobenzene sulfonic acid (TNBS) in rats. Pancreatic hyperalgesia was assessed by referred somatic pain via von Frey filament assay. Neural activation of the NTS was indicated by immunohistochemical staining for Fos. Basic synaptic transmission within the NTS was assessed by electrophysiological recordings. Expression of vesicular glutamate transporters (VGluTs), N-methyl-D-aspartate receptor subtype 2B (NR2B), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subtype 1 (GluR1) was analyzed by immunoblotting. Membrane insertion of NR2B and GluR1 was evaluated by electron microscopy. The regulatory role of the NTS in visceral hypersensitivity was detected via pharmacological approach and chemogenetics in CP rats. RESULTS: TNBS treatment significantly increased the number of Fos-expressing neurons within the caudal NTS. The excitatory synaptic transmission was substantially potentiated within the caudal NTS in CP rats (frequency: 5.87 ± 1.12 Hz in CP rats vs 2.55 ± 0.44 Hz in sham rats, P < 0.01; amplitude: 19.60 ± 1.39 pA in CP rats vs 14.71 ± 1.07 pA in sham rats; P < 0.01). CP rats showed upregulated expression of VGluT2, and increased phosphorylation and postsynaptic trafficking of NR2B and GluR1 within the caudal NTS. Blocking excitatory synaptic transmission via the AMPAR antagonist CNQX and the NMDAR antagonist AP-5 microinjection reversed visceral hypersensitivity in CP rats (abdominal withdraw threshold: 7.00 ± 1.02 g in CNQX group, 8.00 ± 0.81 g in AP-5 group and 1.10 ± 0.27 g in saline group, P < 0.001). Inhibiting the excitability of NTS neurons via chemogenetics also significantly attenuated pancreatic hyperalgesia (abdominal withdraw threshold: 13.67 ± 2.55 g in Gi group, 2.00 ± 1.37 g in Gq group, and 2.36 ± 0.67 g in mCherry group, P < 0.01). CONCLUSION: Our findings suggest that enhanced excitatory transmission within the caudal NTS contributes to pancreatic pain and emphasize the NTS as a pivotal hub for the processing of pancreatic afferents, which provide novel insights into the central sensitization of painful CP.

Anterior insular cortex mediates hyperalgesia induced by chronic pancreatitis in rats.

Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis (CP), but cortical modulation of painful CP remains elusive. This study was designed to examine the role of anterior insular cortex (aIC) in the pathogenesis of hyperalgesia in a rat model of CP. CP was induced by intraductal administration of trinitrobenzene sulfonic acid (TNBS). Abdomen hyperalgesia and anxiety were assessed by von Frey filament and open field tests, respectively. Two weeks after surgery, the activation of aIC was indicated by FOS immunohistochemical staining and electrophysiological recordings. Expressions of VGluT1, NMDAR subunit NR2B and AMPAR subunit GluR1 were analyzed by immunoblottings. The regulatory roles of aIC in hyperalgesia and pain-related anxiety were detected via pharmacological approach and chemogenetics in CP rats. Our results showed that TNBS treatment resulted in long-term hyperalgesia and anxiety-like behavior in rats. CP rats exhibited increased FOS expression and potentiated excitatory synaptic transmission within aIC. CP rats also showed up-regulated expression of VGluT1, and increased membrane trafficking and phosphorylation of NR2B and GluR1 within aIC. Blocking excitatory synaptic transmission significantly attenuated abdomen mechanical hyperalgesia. Specifically inhibiting the excitability of insular pyramidal cells reduced both abdomen hyperalgesia and pain-related anxiety. In conclusion, our findings emphasize a key role for aIC in hyperalgesia and anxiety of painful CP, providing a novel insight into cortical modulation of painful CP and shedding light on aIC as a potential target for neuromodulation interventions in the treatment of CP.

Low-Level Electrical Stimulation of Aortic Root Ventricular Ganglionated Plexi Attenuates Autonomic Nervous System-Mediated Atrial Fibrillation.

OBJECTIVES: This study investigated the effect of electrical stimulation of aortic root ventricular ganglionated plexi (GP) on atrial fibrillation (AF) inducibility. BACKGROUND: The ventricular GP are interconnected with atrial GP to govern heart function, although the effect of ventricular GP modification on control of AF remains unknown. METHODS: Effective refractory periods (ERPs) of test pulmonary veins (PVs) were measured at baseline and during high-level (HL-ES) and low-level (LL-ES) electrical stimulation of the aortic root GP. The arrhythmogenic threshold of acetylcholine and isoproterenol was determined at baseline and during HL-ES and LL-ES. Moreover, AF was induced at PVs by programmed electrical stimulation after HL-ES or LL-ES. Immunohistochemistry staining was performed to examine the autonomic activity from aortic root GP to the PVs. RESULTS: Compared with the baseline group, HL-ES of aortic root GP significantly shortened atrial ERP (95 ± 13 ms vs. 122 ± 9 ms) and PV ERP (104 ± 11 ms vs. 131 ± 12 ms); decreased the threshold concentration of AF by both acetylcholine (1.3 ± 0.2 µmol/l vs. 3.2 ± 0.3 µmol/l) and isoproterenol (0.3 ± 0.1 µmol/l vs. 1.3 ± 0.2 µmol/l); and increased the AF-inducing rate from PVs (90% vs. 30%). In contrast, LL-ES of the GP prevented the shortening of ERP and PV ERP to 125 ± 10 ms and 133 ± 11 ms, respectively; increased threshold levels of acetylcholine and isoproterenol to 5.7 ± 0.4 µmol/l and 3.2 ± 0.3 µmol/l; and decreased the AF-inducing rate to 5%. We also found that the biotinylated dextran amine-containing varicose fibers projected directly from the aortic root GP to the left PVs. CONCLUSIONS: These findings suggest that autonomic innervations of left PVs partly originated from aortic root ventricular GP. Moreover, LL-ES of aortic root ventricular GP suppressed AF inducibility and arose from PVs mediated by the autonomic nervous system.

The independent role of the aortic root ganglionated plexi in the initiation of atrial fibrillation: An experimental study.

OBJECTIVE: The major atrial ganglionated plexi (GP) can initiate atrial fibrillation alone without any contribution from the extrinsic cardiac nervous system. However, if stimulation of the ventricular GP, especially the aortic root GP, can provoke atrial fibrillation (AF) alone is unknown. Our study was designed to investigate the independent role of aortic root GP activity in the initiation of AF. METHODS: In 10 Langendorff-perfused canine hearts, the atrial effective refractory period, pulmonary vein effective refractory period, and percentage of AF induced were measured at baseline and during aortic root GP stimulation. RESULTS: Stimulation of the aortic root GP shortened the atrial effective refractory period from 128 ± 10 ms at baseline to 103 ± 15 ms (P < .05) and shortened the pulmonary vein effective refractory period from 139 ± 14 ms to 114 ± 15 ms (P < .05). Furthermore, the percentage of AF induced in the 10 isolated hearts increased from 10% at baseline to 90% during aortic root GP stimulation (P < .05). CONCLUSIONS: In Langendorff-perfused canine hearts, stimulation of the aortic root GP provokes AF in the absence of any extrinsic cardiac nerve activity. The aortic root GP is an important element in the intrinsic neuronal loop that can increase the risk of AF in isolated heart models.