title: An increase in the cerebral infarction area during fatigue is mediated by il-6 through an induction of fibrinogen synthesis.
abstract: OBJECTIVE
  Our study aimed to investigate the impact of fatigue on the severity of stroke and to explore the underlying mechanisms.
  
  
  METHODS
  Fatigued male rats underwent middle cerebral artery occlusion and the infarcted brain area was determined. Then, coagulation parameters were assessed in the fatigued group and a control group. In addition, the level of fibrinogen was determined in rats deprived of sleep for various numbers of days. To study whether interleukin-6 was involved in fibrinogen synthesis during fatigue, we also measured levels of interleukin-6 in rats deprived of sleep for various numbers of days. Furthermore, brain injury by middle cerebral artery occlusion was measured in wild-type mice, interleukin-6-/- mice and wild-type mice treated with bezafibrate.
  
  
  RESULTS
  More severe cerebral infarction was observed in the fatigued rats, resulting in an infarct ratio of 23.4%. The infarct ratio was significantly increased in the fatigued rats compared with that in the control group (8%, p<0.05). The level of fibrinogen was increased significantly in the fatigued rats compared with that in the control group. In addition, a marked reduction in fibrinogen level was observed in the fatigued interleukin-6-/- mice compared to their wild-type counterparts, whereas no difference was observed between fatigued wild-type mice and interleukin-6-/- rats treated with recombinant human interleukin-6. The reduction in brain injury due to middle cerebral artery occlusion during fatigue was observed in interleukin-6-/- mice and wild-type mice treated with bezafibrate.
  
  
  CONCLUSIONS
  Fatigue could increase stroke severity and was associated with the interleukin-6-induced expression of fibrinogen.
authors: Institute for Drug and Instrument Control of Beijing Military Area Command, , Beijing, China.
authors: Hong
authors: H
authors: Lei
authors: Department of Laboratory Medicine, Chang Hai Hospital, Second Military Medical University, Shanghai, China.
authors: Jian
authors: J
authors: Xu
authors: Institute for Drug and Instrument Control of Beijing Military Area Command, , Beijing, China.
authors: Li-Juan
authors: LJ
authors: Cheng
authors: Institute for Drug and Instrument Control of Beijing Military Area Command, , Beijing, China.
authors: Qi
authors: Q
authors: Guo
authors: Department of Laboratory Medicine, Chang Hai Hospital, Second Military Medical University, Shanghai, China.
authors: An-Mei
authors: AM
authors: Deng
authors: Institute for Drug and Instrument Control of Beijing Military Area Command, , Beijing, China.
authors: Yong-Shen
authors: YS
authors: Li
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D002544:Cerebral Infarction / Q000097:blood* / Q000209:etiology; D004195:Disease Models, Animal; D005221:Fatigue / Q000097:blood* / Q000150:complications; D005340:Fibrinogen / Q000096:biosynthesis*; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D051379:Mice; D017207:Rats, Sprague-Dawley; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D005340:Fibrinogen