J Vet Sci.  2007 Sep;8(3):213-218. 10.4142/jvs.2007.8.3.213.

Effects of endocrine disrupting chemicals on expression of phospholipid hydroperoxide glutathione peroxidase mRNA in rat testes

• Baek IJ
• Yon JM
• Lee SR
• Jin Y
• Kim MR
• Ahn B
• Hong JT
• Choo YK
• Lee BJ
• Yun YW
• Nam SY

• KMID: 1090793
• DOI: http://doi.org/10.4142/jvs.2007.8.3.213

Abstract

Phospholipid hydroperoxide glutathione peroxidase(PHGPx), an antioxidative selenoprotein, is modulated byestrogen in the testis and oviduct. To examine whetherpotential endocrine disrupting chemicals (EDCs) affectthe microenvironment of the testes, the expression patternsof PHGPx mRNA and histological changes were analyzedin 5-week-old Sprague-Dawley male rats exposed to severalEDCs such as an androgenic compound [testosterone (50,200, and 1,000microg/kg)], anti-androgenic compounds [flutamide(1, 5, and 25mg/kg), ketoconazole (0.2 and 1mg/kg), anddiethylhexyl phthalate (10, 50, and 250mg/kg)], andestrogenic compounds [nonylphenol (10, 50, 100, and 250mg/kg), octylphenol (10, 50, and 250mg/kg), and diethyl-stilbestrol (10, 20, and 40microg/kg)] daily for 3 weeks via oraladministration. Mild proliferation of germ cells andhyperplasia of interstitial cells were observed in the testesof the flutamide-treated group and deletion of thegerminal epithelium and sloughing of germ cells wereobserved in testes of the diethylstilbestrol-treated group.Treatment with testosterone was shown to slightly decreasePHGPx mRNA levels in testes by the reverse transcription-polymerase chain reaction. However, anti-androgeniccompounds (flutamide, ketoconazole, and diethylhexylphthalate) and estrogenic compounds (nonylphenol,octylphenol, and diethylstilbestrol) significantly up-regulated PHGPx mRNA in the testes (p<0.05). Thesefindings indicate that the EDCs might have a detrimentaleffect on spermatogenesis via abnormal enhancement ofPHGPx expression in testes and that PHGPx is useful as abiomarker for toxicity screening of estrogenic or anti-androgenic EDCs in testes.

Keyword

biomarker; endocrine disrupting chemicals; phospho-lipid hydroperoxide glutathione peroxidase; RT-PCR; testis

MeSH Terms

Androgen Antagonists/pharmacology
Animals
Diethylhexyl Phthalate/pharmacology
Diethylstilbestrol/pharmacology
Endocrine Disruptors/*pharmacology
Estrogens, Non-Steroidal/pharmacology
Flutamide/pharmacology
Glutathione Peroxidase/*biosynthesis/genetics
Histocytochemistry
Ketoconazole/pharmacology
Male
Phenols/pharmacology
RNA, Messenger/*biosynthesis/genetics
Rats
Rats, Sprague-Dawley
Reverse Transcriptase Polymerase Chain Reaction
Spermatogenesis/drug effects
Testis/*drug effects/*enzymology
Testosterone/pharmacology

Figure

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  Fig. 1 Histological findings in the testes of 8-week-old rats treated with the vehicle alone (A), testosterone (1,000 µg/kg) (B), flutamide (25 mg/kg) (C), diethylhexyl phthalate (250 mg/kg) (D), or diethylstilbestrol (40 µg/kg) (E & F), daily for 3 weeks by oral administration. H&E stain, A-E; ×100, F; ×200.

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  Fig. 2 Analysis of expression levels of PHGPx mRNA in the testes of testosterone-treated rats using reverse transcription-polymerase chain reaction. β-actin: an intrinsic control. The values represent mean ± SD.

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  Fig. 3 Expression pattern of PHGPx mRNA in the testes of flutamide-treated rats using reverse transcription-polymerase chain reaction. β-actin: an intrinsic control. The values represent mean ± SD. *Significantly different from the control at p < 0.05.

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  Fig. 4 Investigation of expression levels of PHGPx mRNA in the testes of diethylhexyl phthalate-treated rats using reverse transcription-polymerase chain reaction. β-actin: an intrinsic control. The values represent mean ± SD.

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  Fig. 5 Expression levels of PHGPx mRNA in the testes of ketoconazole-treated rats. β-actin: an intrinsic control. The values represent mean ± SD. *Significantly different from the control at p < 0.05.

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  Fig. 6 Analysis of expression levels of PHGPx mRNA in the testes of octylphenol-treated rats using reverse transcription-polymerase chain reaction. β-actin: an intrinsic control. The values represent mean ± SD.

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  Fig. 7 RT-PCR amplification of PHGPx mRNA in the testes. Rats were treated with nonylphenol for 3 weeks per oral. β-actin: an intrinsic control. The values represent means ± SD. *Significantly different from the control at p < 0.05.

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  Fig. 8 Expression pattern of PHGPx mRNA in the testes exposed to diethylstilbestrol as measured by RT-PCR. β-actin: an intrinsic control. The values represent mean ± SD. *Significantly different from the control at p < 0.05.

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