title: [Effects of beta-amyloid and apolipoprotein E4 on hippocampal choline acetyl transferase in rats].
abstract: OBJECTIVE
  To investigate the effects of beta-amyloid (Aβ) and apolipoprotein E4(apoE4) on choline acetyl transferase (ChAT) in hippocampus and to explore possible the synergistic effect of both Aβ and apoE4.
  
  
  METHODS
  Male Wistar rats were divided into four groups: control group, Aβ group, apoE4 group and Aβ + apoE4 group. Rats in different group received injection of normal saline, Aβ1-40, apoE4 and Aβ1-40 + apoE4, respectively, into bilateral hippocampus CA1 regions under the control of a brain stereotaxic apparatus. The learning-memory ability with the escape latency and the times of passing platform and the expression of ChAT in hippocampus CA1 regions were documented.
  
  
  RESULTS
  The escape latency at fifth day and the times of passing platform and ChAT mRNA PU values were obtained for the control group (10.75 s ± 2.44 s, 4.13 ± 0.64, and 28.90 ± 4.43), apoE4 group (23.88 s ± 4.32 s, 2.38 ± 0.52, and 20.85 ± 3.98), Aβ group (43.50 s ± 9.78 s, 1.38 ± 0.52, and 16.96 ± 2.53), and Aβ + apoE4 group (70.63 s ± 10.04 s, 0.75 ± 0.71, and 13.01 ± 2.21). Through 5 days of training all animals acquired learning-memory ability with the gradually shortened escape latency, although injection of Aβ1-40 and apoE4 all induced learning-memory damage, due to a significantly prolonged the escape latency at fifth day (P < 0.01) and markedly decreased the times of passing platform (P < 0.01) in both Aβ and apoE4 group than in control group. An interaction between Aβ and apoE4 also was observed, with further prolonged escape latency(P < 0.01). ChAT mRNA PU values were significantly lower in the Aβ group and apoE4 group than in the control group (P < 0.01). Aβ and apoE4 demonstrated interaction in lowering ChAT mRNA level(P < 0.05).
  
  
  CONCLUSIONS
  Both Aβ and apoE4 induce an injury to hippocampal cholinergic system and its learning-memory ability, in which Aβ and apoE4 have a synergistic effect in the initiation of such injury.
authors.affiliation: Department of Neurology, Heping Hospital Affiliated to Changzhi Medical College, Changzhi, China.
authors.forename: Li-xia
authors.initials: LX
authors.lastname: Cui
authors.forename: Feng
authors.initials: F
authors.lastname: Guo
authors.forename: Xin-yi
authors.initials: XY
authors.lastname: Li
mesh_terms: D000544:Alzheimer Disease / Q000201:enzymology / Q000503:physiopathology; D016229:Amyloid beta-Peptides / Q000633:toxicity*; D000818:Animals; D053327:Apolipoprotein E4 / Q000633:toxicity*; D056547:CA1 Region, Hippocampal / Q000201:enzymology* / Q000502:physiology; D002795:Choline O-Acetyltransferase / Q000235:genetics / Q000378:metabolism*; D004357:Drug Synergism; D004924:Escape Reaction / Q000187:drug effects; D007858:Learning / Q000187:drug effects; D008297:Male; D008568:Memory / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
chemical_list: D016229:Amyloid beta-Peptides; D053327:Apolipoprotein E4; D012333:RNA, Messenger; D002795:Choline O-Acetyltransferase