Abstract: Objective To observe the behavioral changes of rats after subchronic exposure to di-(2-ethyl hexyl) phthalate
(DEHP). Methods Twenty-four healthy male SD rats were randomized equally into 4 groups, namely the solvent control group
(sesame oil) and 3 DEHP groups with daily intragastric administration of DEHP at the doses of 150, 450, and 1350 mg/kg for 28
days. The neurobehavioral changes of rats were evaluated by open-field test (OFT) and elevated plus-maze test (EPM), and the
body weight and organ coefficients were measured. Results The rats showed no significant differences in the performance in
OFT or EPM before DEHP exposure. The body weight of the rats increased with the prolonged DEHP exposure, but no
significant differences were found between the treatment groups and the control group (P>0.05). From the third week of
exposure, the weekly food consumption and the food utilization rate showed significant differences between the treatment
groups and the control group (P<0.05 and P<0.01), and the liver and testis coefficients, but not the kidney coefficient, also
differed significantly (P<0.01, P<0.01, and P>0.05). In OFT, the total distance of movement was the longest in high dose
treatment group (P<0.05 vs control group), and the durations of stay in the central area, but not the number of times of entry,
differed significantly between the 3 treatment groups and the control group (P<0.05 and P>0.05). In EPM test, however, the
performances of the rats was all similar between the 4 groups (P>0.05). Conclusion DEHP can affect the locomotor activity and
exploratory behavior of rats after short-term exposure, suggesting its possible hazard in human being.