title: [Effects of 7.5% hypertonic saline pre-injection on postoperative cognitive dysfunction in senile rats].
abstract: OBJECTIVE
  To explore the effects of hypertonic saline (7.5% NaCl) pre-injection on postoperative cognitive function in senile rats.
  
  
  METHODS
  A total of 60 healthy male Sprague-Dawley rats, aged 18 months, weighting 450-500 g, were randomly divided into 3 groups of control (C); model (M) and hypertonic saline (HS) (n = 20 each). At 30 min pre-operation, the rats of groups C and HS received an injection of 7.5% hypertonic sodium 4 ml/kg via tail vein. And the same volume of saline was injected in group M. Rats of groups M and HS were anesthetized by inhaling 3% sevoflourane and underwent splenectomy while group C inhaled merely pure oxygen. Escape latency and frequency of crossing original platform were assessed by Morris water maze on 1 day pre-operation and 1, 3, 7 days post-operation. The rats were randomly taken for detecting the intracellular [Ca²⁺]i and apoptotic rate of hippocampal neuron with flow cytometry. And ultrastructures of hippocampal neurons were observed with transmission electron microscope at 1 day pre-operation and 1, 7 days post-operation.
  
  
  RESULTS
  Compared with pre-dosing value, escape latency was significantly prolonged, the frequency of crossing original platform decreased and apoptotic rate and [Ca²⁺]i increased at each time point post-operation in groups M and HS. And no significant changes were found in the above-mentioned parameters in group C. Compared with group M, escape latency was significantly shortened, the frequency of crossing original platform increased and apoptotic rate and [Ca²⁺]i decreased at each time point post-operation in group HS. Pathological changes were found in groups M and HS and the damage was more severe in group M than that in group HS. And no significant pathological change was found in group C.
  
  
  CONCLUSIONS
  Infusing 7.5% hypertonic saline can improve postoperative cognitive function of senile rats. And it may be due to a decreased apoptotic rate of hippocampal neurons.
authors: Department of Anesthesiology, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050001, China.
authors: Tianbao
authors: T
authors: Yuan
authors: Department of Anesthesiology, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050001, China.
authors: Jinhua
authors: J
authors: He
authors: Department of Anesthesiology, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050001, China.
authors: Mingming
authors: M
authors: Xie
authors: Department of Anesthesiology, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050001, China.
authors: Shuping
authors: S
authors: Huo
authors: Department of Anesthesiology, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050001, China. Email: 13933178001@163.com.
authors: Qiujun
authors: Q
authors: Wang
mesh_terms: D000375:Aging; D000818:Animals; D003072:Cognition Disorders; D006624:Hippocampus; D008297:Male; D009474:Neurons; D051381:Rats; D017207:Rats, Sprague-Dawley; D012462:Saline Solution, Hypertonic
chemical_list: D012462:Saline Solution, Hypertonic