title: Experimental study on the effect of controlled hypotension levels on rabbit CA1 neurons.
abstract: OBJECTIVE
  The present study investigated the effect of controlled hypotension (CH) levels regulated by nitroprusside on hippocampal CA1 neurons.
  
  
  METHODS
  All experimental rabbits were randomly divided into five groups to perform CH for recording their vital signs and survived for a certain time. The arterial blood was collected to measure the serum levels of interleukin 6 and tumor necrosis factor α and then the brain tissues were perfused and sectioned to carry out hematoxylin-eosin staining, TdT-mediated dUTP nick end labeling fluorescence, c-fos immunohistochemistry, and ultrastructural observation of hippocampal neuronal mitochondria. All data were analyzed with SPSS13.0 software, and P < 0.05 was indicated as statistically significant.
  
  
  RESULTS
  Heart rate, mean arterial pressure, and the dosage of sodium nitroprusside were not statistically significant between groups, but at T2, heart rate levels in groups II-IV were lower than those in groups I and V. Simultaneously, interleukin 6 was remarkably overexpressed in group II than in other groups at T2, whereas tumor necrosis factor α was higher in groups I-III than in groups IV and V. At the light and electronic microscopic levels, the CA1 regional neurons of group IV were more seriously damaged and deranged compared with other groups so was the expression of c-fos. However, fluorescence from TdT-mediated dUTP nick end labeling assay was more intensive in groups II-IV than that in other groups. Results further showed that Flameng scores of mitochondria were the highest in group IV, but they were not statistically significant among the other groups.
  
  
  CONCLUSIONS
  The different levels of CH remarkably affected the functional activities of hippocampal CA1 neurons; with the decrease of mean arterial pressure, neuronal apoptosis, and c-fos expression was gradually increased and reached the peak in 45% of basic values of blood pressure.
authors.affiliation: Department of Anesthesiology, Guangdong NO. 2 Provincial People's Hospital, Guangdong Provincial Emergency Hospital, Guangzhou, Guangdong Province, China.
authors.forename: Bingbing
authors.initials: B
authors.lastname: Liu
authors.forename: Diawei
authors.initials: D
authors.lastname: Zhou
authors.forename: Hongyan
authors.initials: H
authors.lastname: Huang
authors.forename: Xiaoshan
authors.initials: X
authors.lastname: Xiao
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000009:adverse effects / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D056547:CA1 Region, Hippocampal / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D004195:Disease Models, Animal; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D007022:Hypotension / Q000097:blood / Q000139:chemically induced / Q000503:physiopathology*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008928:Mitochondria / Q000648:ultrastructure; D009474:Neurons / Q000378:metabolism / Q000473:pathology* / Q000502:physiology; D009599:Nitroprusside / Q000009:adverse effects / Q000494:pharmacology*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D011817:Rabbits; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D000959:Antihypertensive Agents; D015850:Interleukin-6; D016760:Proto-Oncogene Proteins c-fos; D014409:Tumor Necrosis Factor-alpha; D009599:Nitroprusside