title: Optimizing the parameters of vagus nerve stimulation by uniform design in rats with acute myocardial infarction.
abstract: Vagus nerve stimulation (VNS) has been shown to improve left ventricular function and survival in rats with acute myocardial infarction (AMI), and this maneuver has also been adopted clinically for the treatment of patients with chronic heart failure (CHF). Recent in vitro and in vivo studies have suggested that VNS can modulate the level of pro-inflammatory factors. Despite the beneficial effects of VNS, the stimulation parameters for obtaining favorable outcomes appear highly variable. To optimize VNS parameters, we set up different stimulation protocols with different pulse width (1-2 ms), frequency (1-6 Hz), voltage (1-6 V) and duration (40-240 min) of VNS by uniform design (UD). Rats were divided into seven groups with (Group1-Group6) or without VNS (MI group). Our results demonstrate that (1) the parameter sets in Group1, Group2 and Group3 yield the best post-MI protection by VNS, while the protective role were not observed in Group4, Group5 and Group6; (2) baroreflex sensitivity and the α7 nicotinic acetylcholine receptor level were also increased in Group1, Group2 and Group3. (3) the parameter set in Group1 (G1:1 ms, 2 Hz, 3 V, 240 min) is judged the most optimal parameter in this study as rats in this group not only showed a reduced myocardial injury with better-preserved cardiac function compared with other groups, more important, but also exhibited minimal heart rate (HR) reduction. (4) the duration of VNS plays an important role in determining the protection effect of VNS. In conclusion, VNS displays a beneficial role in Group1, Group2 and Group3. Of note, the parameter set in Group1 provides the most optimal cardioprotective effect. These results may provide insight into development of novel treatment for ischemic heart diseases.
authors.affiliation: Department of Pharmacology, Xi'an Jiaotong University, College of Medicine, Xi'an, People's Republic of China.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Kong
authors.forename: Jin-Jun
authors.initials: JJ
authors.lastname: Liu
authors.forename: Tyzh-Chang
authors.initials: TC
authors.lastname: Hwang
authors.forename: Xiao-Jiang
authors.initials: XJ
authors.lastname: Yu
authors.forename: Mei
authors.initials: M
authors.lastname: Zhao
authors.forename: Ming
authors.initials: M
authors.lastname: Zhao
authors.forename: Bing-Xiang
authors.initials: BX
authors.lastname: Yuan
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Kang
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.forename: Wei-Jin
authors.initials: WJ
authors.lastname: Zang
mesh_terms: D000818:Animals; D017704:Baroreflex; D004195:Disease Models, Animal; D006339:Heart Rate; D006352:Heart Ventricles / Q000294:innervation / Q000503:physiopathology; D006439:Hemodynamics; D008297:Male; D009203:Myocardial Infarction / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D011978:Receptors, Nicotinic / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014630:Vagus Nerve / Q000502:physiology*; D055536:Vagus Nerve Stimulation
chemical_list: D011978:Receptors, Nicotinic; D014409:Tumor Necrosis Factor-alpha