[Effect of neonatal exposure to environmental pollutants on the DNA methylation of rat testis].
OBJECTIVE
To investigate the effects of neonatal exposure of DNA methylation inhibitor, Cadmium and PCB153 on DNA methylation, apoptosis and spermatogenesis in SD rats.


METHODS
Neonatal SD rats were randomly divided into 10 groups and received oral administrations of PCB153 (0.025, 0. 250, 2.500 mg/kg), or Cadmium (1, 2, 4 mg/kg), or positive control 5-Aza-CdR (0.025, 0.250 mg/kg), or vehicle control for five days from PND3. Half of the rats were killed 24 h after the last administration. The remains were fed until 12 weeks. Sperm numbers, apoptosis and DNA methylation levels in testis were investigated.


RESULTS
The daily sperm production was significantly decreased in each neonatal exposed group (P < 0.05). Neonatal rats exposed to 5-Aza-CdR and Cadmium reduced the global DNA methylation level, increased apoptosis, while PCB153 exposure did not significantly change DNA methylation and apoptosis.


CONCLUSIONS
Neonatal rats exposed to chemicals could reduce spermatogenesis via multiple pathways. Lower DNA methylation and increased neonatal apoptosis were suggested as one of the causes.
Li
Ke-Yong
KY
Department of Occupational Health, School of Public Health of Fudan University, Shanghai 200032, China.
Xiao
Wu-Sheng
WS
Wu
Qing
Q
Chang
Xiu-Li
XL
Zhou
Zhi-Jun
ZJ
Zhang
Jie
J
Su
De-Qi
DQ
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects; D002104:Cadmium / Q000633:toxicity*; D019175:DNA Methylation / Q000187:drug effects*; D008297:Male; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013091:Spermatogenesis / Q000187:drug effects*; D013737:Testis / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
D002104:Cadmium; D011078:Polychlorinated Biphenyls; C014024:2,4,5,2',4',5'-hexachlorobiphenyl