title: Cardiac Dysregulation and Myocardial Injury in a 6-Hydroxydopamine-Induced Rat Model of Sympathetic Denervation.
abstract: BACKGROUND
  Cardiac sympathetic denervation is found in various cardiac pathologies; however, its relationship with myocardial injury has not been thoroughly investigated.
  
  
  METHODS
  Twenty-four rats were assigned to the normal control group (NC), sympathectomy control group (SC), and a sympathectomy plus mecobalamin group (SM). Sympathectomy was induced by injection of 6-OHDA, after which, the destruction and distribution of sympathetic and vagal nerve in the left ventricle (LV) myocardial tissue were determined by immunofluorescence and ELISA. Heart rate variability (HRV), ECG and echocardiography, and assays for myocardial enzymes in serum before and after sympathectomy were examined. Morphologic changes in the LV by HE staining and transmission electron microscope were used to estimate levels of myocardial injury and concentrations of inflammatory cytokines were used to reflect the inflammatory reaction.
  
  
  RESULTS
  Injection of 6-OHDA decreased NE (933.1 ± 179 ng/L for SC vs. 3418.1± 443.6 ng/L for NC, P < 0.01) and increased NGF (479.4± 56.5 ng/mL for SC vs. 315.85 ± 28.6 ng/mL for NC, P < 0.01) concentrations. TH expression was reduced, while ChAT expression showed no change. Sympathectomy caused decreased HRV and abnormal ECG and echocardiography results, and histopathologic examinations showed myocardial injury and increased collagen deposition as well as inflammatory cell infiltration in the cardiac tissue of rats in the SC and SM groups. However, all pathologic changes in the SM group were less severe compared to those in the SC group.
  
  
  CONCLUSIONS
  Chemical sympathectomy with administration of 6-OHDA caused dysregulation of the cardiac autonomic nervous system and myocardial injuries. Mecobalamin alleviated inflammatory and myocardial damage by protecting myocardial sympathetic nerves.
authors.affiliation: Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, P.R. China.
authors.forename: Yue-Hua
authors.initials: YH
authors.lastname: Jiang
authors.affiliation: Shandong University of Traditional Chinese Medicine, Jinan, Shandong, P.R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
authors.affiliation: Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, P.R. China.
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Yang
authors.affiliation: Shandong University of Traditional Chinese Medicine, Jinan, Shandong, P.R. China.
authors.forename: Du-Fang
authors.initials: DF
authors.lastname: Ma
authors.affiliation: Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, P.R. China.
authors.forename: Hai-Qing
authors.initials: HQ
authors.lastname: Lin
authors.affiliation: Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, P.R. China.
authors.forename: Wen-Ge
authors.initials: WG
authors.lastname: Su
authors.affiliation: Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, P.R. China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, P.R. China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
mesh_terms: D000818:Animals; D016207:Cytokines / Q000032:analysis; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006321:Heart / Q000187:drug effects / Q000294:innervation / Q000503:physiopathology*; D006335:Heart Injuries / Q000503:physiopathology*; D006352:Heart Ventricles / Q000737:chemistry / Q000294:innervation / Q000473:pathology / Q000503:physiopathology; D008297:Male; D046529:Microscopy, Electron, Transmission; D016627:Oxidopamine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013562:Sympathectomy / Q000009:adverse effects; D014630:Vagus Nerve / Q000187:drug effects
chemical_list: D016207:Cytokines; D016627:Oxidopamine