OBJECTIVETo evaluate the effects of di-butyl phthalate(DBP) on the sperm motility and oxidative stress in rats.

METHODSHealthy 6-week-old male Sprague Dawlay rats were randomly divided into 4 groups with 8 in each group. DBP dissolved in peanut oil was administered by gavage at dosage of 0, 250, 500, 1,000 mg/(kg.d). After 4-week DBP exposure, the animals were killed and the organs were selected and weighed. The sperm VCL, VSL, VAP, BCF, ALH, LIN, MAD and STR in the cauda epididymis were assessed by computer assisted sperm analysis (CASA), and the activities of superoxide dismutase (SOD) and the contents of malondialdehyde (MDA) in serum and testis homogenate were measured simultaneously. The increase of body weight per day and the organ body weight ratio changes of the liver, testes and epididymides were also observed.

RESULTSThe liver organ body weight ratios of the treated groups were higher than those of the control (P < 0.01), while the testis organ body weight ratios were lower at dosage of 1,000 mg/(kg.d) DBP. Compared with the control group, the parameters of rat sperm VCL and ALH declined significantly at dosage of 1,000 mg/(kg.d) DBP. In addition, DBP showed inhibiting effect on SOD activities in the testis, and it was significant in the highest exposure group compared with the control (P < 0.05). However, there were no differences in serum SOD activities between the treated groups and the control.

CONCLUSIONDBP exposure may affect the sperm motility and the anti-oxidative systems. The testis is a vital target organ influenced by DBP.