Promotion of proliferation of prostate in aged rats by low-dose di(2-ethylhexyl) phthalate / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To investigate the proliferation effect of di(2-ethylhexyl) phthalate (DEHP) on prostate in aged rats at the environmental exposure dose and the possible mechanism.METHODS Thirty-two male Sprague-Dawley rats,aged 1.5 years,were randomly divided into 4 groups (8 rats per group) and treated with DEHP (30,90 and 270 μg· kg-1,ig) and vehicle once daily respectively for 4 weeks.All the animals were anesthetized with pentobarbital sodium and sacrificed on the day subsequent to the last treatment.① Abdominal aortic blood samples were collected,and serum estradiol (E2),testosterone (T) and prolactin (PRL) levels were assayed by ELISA.② The prostate tissues were dissected and categorized into different lobes,weighed and measured.The prostate relative mass was calculated.③ The morphological changes were detected by HE staining and prostate epithelial height was analyzed with microscopic image analysis software.RESULTS Compared with vehicle control group,the prostate relative mass,dorsolateral prostate mass,and dorsolateral prostate index in DEHP 270 μg· kg-1 group were significantly higher (P＜0.05).The height of the ventral prostate epithelium in DEHP 30,90 and 270 μg· kg-1 groups was increased significantly (P＜0.01),so was the height of dorsal prostate epithelium in DEHP 270 μg· kg-1 group (P＜0.01).There were no significant changes in levels of E2,PRL or T in DEHP 30,90 and 270 μg· kg-1 groups,but the ratios of E2/T in DEHP 30 and 270 μμg· kg-1 groups were increased significantly (P＜0.05).CONCLUSION Low-dose DEHP could promote the proliferation of prostatic hyperplasia in the aged rats,which might be associated with the relative levels of endogenous hormone.