Abstract: Objective:To investigate the effect of di(2-ethylhexyl) phthalate (DEHP) on the uterus tissue of female rats, and to clarify the mechanism of uterine toxicity of DEHP in the female rats. Methods:A total of 48 Wistar female rats were randomly divided into control group(given corn oil), low, middle, and high doses of DEHP groups (given 300, 1 000, and 3 000 mg·kg^-1·d^-1 DEHP;1/100,1/30,and 1/10 LD₅₀)(n=12). The rats in various groups were sacrificed during anoestrum, the body weights were recorded and uterine organ coefficients of the rats in various groups were calculated. The pathomorphology of the uterus tissue of the rats in various groups was detected by HE staining. The expression levels of follicle stimulating hormonereceptor (FSHR) and luteinizing hormone receptor (LHR) in uterus tissue of the rats in various groups were detected by immunohistochemistry. Results:Compared with control group, the body weights of the rats in different doses of DEHP groups were decreased (P<0.05) with a dose-effect relationship; there were no significant differences in uterine organ coefficients of the rats in various groups (P>0.05). Macroscopically, the morphology of the uterus of rats in control group was normal; in middle and high doses of DEHP groups, the uterus showed distorted and the tube wall became thinner; different degrees of hydrops, congestion and swelling were seen on the serosal surface of the uterus. The microscopic observation results showed that in different doses of DEHP groups the endometrium nuclei appeared pseudostratified phenomenon; the epithelial hyperplasia and endothelial fibrosis were found in the endometrium; the gland number in the lamina propria was decreased,and part of the glands were depauperate. Compared with control group, the expression levels of FSHR in uterus tissue of the rats in different doses of DEHP groups had no significant differences(P>0.05),and the expression levels of LHR were decreased(P<0.05); the expression levels of LHR in uterus tissue of the rats in middle and high doses of DEHP groups were significantly lower than that in low dose of DEHP group (P<0.05). Conclusion:DEHP can lead to the weight loss and the pathological changes in the uterus tissue of the female rats, and has a uterine toxicity effect on the female rats.

Key words: plasticizer, di(2-ethylhexyl) phthalate, female, uterus