Short term effects of di-(2-ethylhexyl) phthalate on testes, liver, kidneys and pancreas in mice

Yumi Miura¹, Munekazu Naito¹, Maira Ablake², Hayato Terayama¹, Shuang-Qin Yi¹, Ning Qu¹, Lin-Xian Cheng¹, Shigeru Suna³ Fumihiko Jitsunari³, Masahiro Itoh<sup>1

1</sup>Department of Anatomy, Tokyo Medical University, Tokyo 160-8402, Japan, ²Department of Histology and Embryology, Xin Jiang Medical University, Xinjiang 830001, China, ³Department of Hygiene and Public Health, Faculty of Medicine, Kagawa University, Kagawa 761-0783, Japan

DOI: 10.1111/j.1745-7262.2006.00220.x

Abstract
Aim: To determine the biochemical effect of DEHP on testes, liver, kidneys and pancreas on day 10, when degeneration of the seminiferous epithelium is in progress. Methods: Diets containing 2 % DEHP were given to male ICR mice for 10 days. The dose of DEHP was 0.9 ± 0.52 mg / mouse / day. Their testes, livers, kidneys and pancreata were examined for detection of mono-(2-ethylhexyl) phthalate (MEHP), NOx produced by peroxidation of nitric oxide with free radicals, and lipid peroxidation induced by a chain reaction of free radicals. Results: Histological observation and serum analysis showed the presence of severe spermatogenic disturbance, Leydig cell dysfunction, liver dysfunction and dehydration. Unexpectedly, the concentration of MEHP in the testes was extremely low compared with that in the liver. However, the concentration of the NOx in the testes was as high as the hepatic concentration. Furthermore, free radical-induced lipid peroxidation was histochemically detected in the testes but not in the liver. Conclusion: The results indicate that DEHP-induced aspermatogenesis is to the result of the high sensitivity of the testicular tissues to MEHP rather than the specific accumulation or uptake of circulating MEHP into the testes.

Keywords: phthalate, nitrogen oxide, free radical, testis

Correspondence to: Dr Munekazu Naito, Department of Anatomy, Tokyo Medical University, Shinjuku 6-1-1, Shinjuku-ku, Tokyo 160-8402, Japan.
Tel: +81-3-3351-6141, Fax: +81-3-3341-1137
E-mail: anatomy@tokyo-med.ac.jp
Received: 2006-01-24 Accepted: 2006-06-05