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Motorcycle exhaust induces reproductive toxicity and testicular interleukin-6 in male rats.

Authors :
Huang JY
Liao JW
Liu YC
Lu SY
Chou CP
Chan WH
Chen SU
Ueng TH
Source :
Toxicological sciences : an official journal of the Society of Toxicology [Toxicol Sci] 2008 May; Vol. 103 (1), pp. 137-48. Date of Electronic Publication: 2008 Jan 30.
Publication Year :
2008

Abstract

Motorcycle exhaust (ME) from two-stroke engines contains many toxicants and poses a potential health hazard. The major objectives of the present study were to investigate the male reproductive toxicity of ME and the underlying mechanisms of toxicity. Male Wistar rats were exposed to ME by inhalation 1 h each in the morning and afternoon, Monday through Friday. Exposures to 1:50 diluted ME for 4 weeks or to 1:10 diluted ME for 2 and 4 weeks showed concentration- and time-dependent decreases of testicular weight, spermatid number, and cauda epididymal sperm number. Subsequent studies were done using 4-week exposure to 1:10 diluted ME. ME caused histopathological changes including testicular spermatocytic necrosis and seminiferous tubule atrophy and cauda epididymal formation of clusters of pyknotic and necrotic sperm cells. ME-exposed male rats mated with untreated females showed decreases of male mating index and female fertility index and an increase of implantation site loss. ME decreased 7-ethoxycoumarin O-deethylase and superoxide dismutase activities but induced proinflammatory cytokine interleukin-6 (IL-6) messenger RNA (mRNA) in the testis. Male rats were exposed to ME with or without cotreatment with 50 mg/kg vitamin E orally for 4 weeks. ME decreased serum testosterone concentration. This effect was reversed by cotreatment with vitamin E. ME decreased testicular spermatid number and induced IL-6 mRNA and protein. These effects were also reversed by the vitamin E cotreatment. The present findings show that ME causes male reproductive effects and induces testicular IL-6 in rats by mechanisms involving induction of oxidative stress and inhibition of steroidogenesis.

Details

Language :
English
ISSN :
1096-0929
Volume :
103
Issue :
1
Database :
MEDLINE
Journal :
Toxicological sciences : an official journal of the Society of Toxicology
Publication Type :
Academic Journal
Accession number :
18234736
Full Text :
https://doi.org/10.1093/toxsci/kfn020