[Reproductive toxicity of formaldehyde to adult male rats and the functional mechanism concerned].
OBJECTIVE
To assess the reproductive toxicity exerted by formaldehyde to adult male rats and the functional mechanism therein in volved.


METHODS
Forty adult male rats were randomLy divided into 4 groups. One group served as control. The other 3 groups as exposure groups were intraperitoneally injected with formaldehyde at the dose of 0.10 mg/kg x d, 1.00 mg/kg x d, 10 mg/kg x d respectively and continuously for 14 days. The weight and morphology of testis, the quality and amount of sperm, and the serum hormone were examined. In addition, the apoptosis rate of testis tissue was examined by TUNEL and the expression of Fas gene in testis tissue by immunohistochemistry.


RESULTS
Compared with control, the weight of testis in the high-dose formaldehyde exposure group significantly decreased (P < 0.05); the convoluted tubules became atrophied, the layers of seminiferous epithelium decreased, the arrangement of seminiferous epithelium was in disorder in the medium- and high-dose formaldehyde exposure groups; the sperm count and sperm motility significantly decreased (P < 0.05), the percent of abnormal sperm significantly increased (P < 0.05)in the medium- and high-dose formaldehyde exposure groups; the serum testosterone content mildly decreased and the serum FSH and LH content mildly increased in the formaldehyde exposure groups, but no statistically significant difference was observed. Moreover, in comparison with control, the apoptosis rate and the expression of Fas gene increased in the testicular tissue of rats in the medium- and high-dose formaldehyde exposure groups (P < 0.05). The apoptosis rate was significantly correlated with the expression of Fas gene (r = 0.8832, P < 0. 05).


CONCLUSIONS
Formaldehyde exerts reproductive toxicity to adult male rats, and Fas-mediated apoptosis may be one of the functional mechanisms involved in the reproductive toxicity of formaldehyde.
Zhou
Dang-xia
DX
Research Center of Reproductive Medicine, School Medicine, Xi'an Jiaotong University, Xi'an 710061, China.
Qiu
Shu-dong
SD
Zhang
Jie
J
Wang
Zhi-yong
ZY
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005557:Formaldehyde / Q000633:toxicity*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013076:Sperm Count; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000473:pathology; D013737:Testis / Q000473:pathology*; D013739:Testosterone / Q000097:blood; D019014:fas Receptor / Q000235:genetics*
D019014:fas Receptor; D005557:Formaldehyde; D013739:Testosterone