title: Role of the sympathetic nervous system and spleen in experimental stroke-induced immunodepression.
abstract: BACKGROUND
  The mechanism of stroke-induced immunodepression syndrome (SIDS) remains uncertain. Some studies suggest that hyperactivation of the sympathetic nervous system (SNS) may be the key factor underlying SIDS. Catecholamines impair early lymphocyte response, which can increase the risk of stroke-associated infection (SAI).
  
  
  METHODS
  Our study focused on dynamic changes of metanephrine (MN), normetanephrine (NMN), cytokines, and spleen volume in the rat middle cerebral artery occlusion (MCAO) model.
  
  
  RESULTS
  After MCAO, there is hyperactivation of SNS and pro-/anti-inflammatory imbalance, indicating systemic immunodepression. In addition, rat spleen size was reduced. Correlation analysis indicated that MCAO-induced spleen size reduction correlated with the changes in MN, NMN, and cytokines. Blocking SNS with propranolol can partly reverse the immunodepression and the reduction in spleen volume.
  
  
  CONCLUSIONS
  Taken together, these findings suggest that acute ischemic stroke induces over-activation of the SNS, which lowers the threshold of infection and increases the risk of infection.
authors.affiliation: Department of Neurology, Zhong-Da Hospital, Southeast University, Nanjing, China (mainland).
authors.forename: Fu-Ling
authors.initials: FL
authors.lastname: Yan
authors.affiliation: Department of General Medicine, Zhong-Da Hospital, Southeast University, Nanjing, China (mainland).
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Zhang
mesh_terms: D000818:Animals; D020520:Brain Infarction / Q000150:complications / Q000473:pathology; D007165:Immunosuppression Therapy; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000473:pathology; D007274:Injections, Intraperitoneal; D007371:Interferon-gamma / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D053583:Interleukin-1beta / Q000097:blood; D018810:Magnetic Resonance Angiography; D008297:Male; D008676:Metanephrine / Q000097:blood; D009647:Normetanephrine / Q000097:blood; D009929:Organ Size; D011433:Propranolol / Q000008:administration & dosage; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000276:immunology* / Q000473:pathology*; D013194:Staining and Labeling; D020521:Stroke / Q000097:blood / Q000150:complications / Q000276:immunology*; D013564:Sympathetic Nervous System / Q000276:immunology* / Q000473:pathology*
chemical_list: D053583:Interleukin-1beta; D009647:Normetanephrine; D016753:Interleukin-10; D008676:Metanephrine; D007371:Interferon-gamma; D011433:Propranolol