[The effect of continuous low doses X-ray on the proliferation of pyramidal cell in hippocampus CA1 in prenatal rats].
OBJECTIVE
To explore the effect of low doses X-ray on proliferation of hippocampal pyramidal cell in the area of CA1 in prenatal rat and its relevant mechanism.


METHODS
A total of 25 pregnant rats were randomly divided into four experimental groups and one control group. The experimental groups, in a duration of consistent 18 days, respectively received different doses as follows: 0.015 mGy/d, 0.03 mGy/d, 0.06 mGy/d and 0.09 mGy/d. The control group received sham radiation. To observe the density and width of hippocampal pyramidal cell in the area of CA1 by HE stained and observe the expression of the ERK1/2 by IHM.


RESULTS
(1) Except C group, all other groups presented increment in width of the level of hippocampal pyramidal cell, compared with C group; H group, M group, L1 group and L2 group were higher than that (F value respectively were 8.475, 33.42, 14.395, 44.955; P value respectively were 0.002, 0.048, 0.030, 0.012). But the phenomenon of inhomogeneity in width in H group was observed, at the same time, the density of cell in H group became looser (F = 4.466, P = 0.017). (2) The expression of ERK1/2 in the hippocampus CA1 was seen in cytoplasm of every group, the average optical density of positive ERK1/2 protein significantly increased in L1 group and L2 group, compared with control group respectively (F value respectively were 4.561, 4.103, P value respectively were 0.044, 0.035).


CONCLUSIONS
Low doses X-ray could promote proliferation of hippocampus CA1 cell in prenatal. The reason could be the increment of the ERK1/2 protein induced by X-ray. When the doses reached 0.09 mGy/d, the excesses proliferation phenomenon was observed.
Department of Radiology, Tongji Hospital of Tongji University, Shanghai 200065, China.
Wei
W
Zhang
Pei-jun
PJ
Wang
Wen-xia
WX
Jiang
Ning-xin
NX
Dong
Ming-hua
MH
Li
Jing
J
Zhang
Hong
H
Jiang
Shuang-qing
SQ
Chen
Xiao-long
XL
Gao
D000818:Animals; D049109:Cell Proliferation / Q000528:radiation effects*; D005260:Female; D006624:Hippocampus / Q000166:cytology* / Q000528:radiation effects; D008297:Male; D018811:Maternal Exposure; D009474:Neurons / Q000166:cytology / Q000528:radiation effects*; D011247:Pregnancy; D017966:Pyramidal Cells / Q000166:cytology / Q000528:radiation effects*; D011839:Radiation, Ionizing; D051381:Rats; D014965:X-Rays