[Intermittent hypoxia promotes the expressions of rat hippocampal neuronal hypoxia-inducible factor-1 and survivin].
OBJECTIVE
To establish an intermittent hypoxia (IH) animal model by simulating the features of obstructive sleep apnea-hypopnea syndrome and observe the expressions of hypoxia-inducible factor-1 (HIF-1) and survivin and the occurrence of apoptosis in the hippocampal CA1 neuron of rats with early IH.


METHODS
Male Wistar rats (n=72) were randomly divided into control group and IH group. In control group, rats were given compressed air and in IH group, rats were exposed to 50 mL/L IH for 7 hours a day, lasting 3, 7, 14 and 21 days, respectively. The expressions of HIF-1 and survivin in hippocampal CA1 were detected by immunohistochemistry and the neuronal apoptosis index was calculated by TUNEL.


RESULTS
Compared with control group, apoptosis index in the third day of 5% IH group had no significant difference, while apoptosis index in IH 7-, 14- and 21-day groups were significantly higher than that in control group, and on the 21st day it reached a peak. The expressions of HIF-1 and survivin protein in 5% IH group significantly increased as compared with control group at each time point, and they peaked on the 14th day, then decreased gradually. There was a positive relationship between the expressions of HIF-1 and survivin.


CONCLUSIONS
Early IH can induce HIF-1 and survivin protein expressions in rat hippocampal CA1, and their expressions may play an important role in the regulation of neuronal apoptosis.
Department of Respiratory Medicine, Hospital Affiliated to Hebei United University, Tangshan 063000, China.
Ling
L
Wang
Department of Respiratory Medicine, Hospital Affiliated to Hebei United University, Tangshan 063000, China.
Panpan
P
Zhang
Department of Respiratory Medicine, Hospital Affiliated to Hebei United University, Tangshan 063000, China.
Hongyang
H
Wang
Department of Respiratory Medicine, Hospital Affiliated to Hebei United University, Tangshan 063000, China.
Jiangtao
J
Yu
Department of Respiratory Medicine, Hospital Affiliated to Hebei United University, Tangshan 063000, China.
Min
M
Zhang
Department of Respiratory Medicine, Hospital Affiliated to Hebei United University, Tangshan 063000, China.
Xiaoqing
X
Han
Department of Respiratory Medicine, Hospital Affiliated to Hebei United University, Tangshan 063000, China.
Lin
L
Li
Department of Respiratory Medicine, Hospital Affiliated to Hebei United University, Tangshan 063000, China.
Chen
C
Liu
D000818:Animals; D017209:Apoptosis; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D000860:Hypoxia / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D051793:Hypoxia-Inducible Factor 1 / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008869:Microtubule-Associated Proteins / Q000235:genetics* / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D020181:Sleep Apnea, Obstructive / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D000077022:Survivin; D015854:Up-Regulation
C516989:Birc5 protein, rat; D051793:Hypoxia-Inducible Factor 1; D008869:Microtubule-Associated Proteins; D000077022:Survivin; D010100:Oxygen