[Effect of methylmercury chloride on the c-fos expression in brain nerve cells of the rats].
OBJECTIVE
In order to study the mechanism of injury in the brain development caused by methylmercury chloride (MMC) and its effects on the c-fos expression in brain nerve cells of the rats with experiments in vitro and in vivo.


METHODS
In vitro, the effect of MMC on c-fos expression in the cultured nerve cells was observed by immunocytochemistry(SP method). In vivo, Wistar pregnant rats were administered 4 mg MMC per kg of body weight by a gastric tube from the 7th to the 10th gastational days. On the 1st, 3rd, 5th, 7th, 10th and 15th days after birth, the rats were killed and tissue sections were prepared from their brain, respectively. The expression of c-fos was detected by SP method.


RESULTS
The percentage of c-Fos-positive neuron in rats brain began to increase at 0.5 hours after being cultured in in vitro with 0.3 mumol/L MMC continuously, and increased gradually as length of the exposure to MMC prolonged. The percentage of c-Fos-positive of cultured nerve cells in vitro were (6.97 +/- 2.86)%, (66.86 +/- 5.32)% and (64.49 +/- 3.09)% in the experimental groups exposed to MMC for 10 min, 2 h and 6 h, respectively. In vivo, the percentage of Fos-positive neuron nuclei decreased with development of neonatal rats. The percentage of c-Fos-positive neuron in the experimental groups was higher than that in the control groups and decreased with length of development. The percentages of c-Fos-positive neuron were (47.01 +/- 3.79)% and (46.71 +/- 1.96)% in the experimental group 1 and 3 d, and (35.8 +/- 3.04)% and (33.35 +/- 1.06)% in the control group, respectively, with very significant difference.


CONCLUSIONS
It is concluded that MMC could induce c-fos over-expression in the nerve cells of the rat brain, which could explain the mechanism of injury to brain development caused by MMC.
Guo
L
L
Department of Toxicology, School of Preventive Medicine, Jilin University, Changchun 130021, China.
Bi
X
X
Zhang
X
X
D000818:Animals; D001921:Brain / Q000166:cytology / Q000187:drug effects*; D002478:Cells, Cultured; D005260:Female; D008767:Methylmercury Compounds / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D015854:Up-Regulation
D008767:Methylmercury Compounds; D016760:Proto-Oncogene Proteins c-fos; C004925:methylmercuric chloride