Study On Reproductive Toxicity And Genotoxicity Of BBP In Male Mice

Butyl benzyl phthalate (BBP) is a worldly organic pollution, which is mass produced and wildly used. BBP was attracted by more and more attention of experts. It can influence the reproduction and development system of male animals, but its mechanism of action is still not clear currently. To further calibrate the reproduction toxicity of BBP, We used the single cell gel electrophoresis (SCGE), spermatic DNA damages assay and RT-PCR assay. It can provide as laboratorial basis for the study of its damage mechanism.1. Effects of Butyl benzyl phthalate on enzymes correlated with energy metabolism in mice's testisActivities of succinate dehydrogenase (SDH), lactate dehydrogenase (LDH) and ATPase in homogenate of the testis were determined after exposed to BBP. It was observed that the activities of SDH, LDH and ATPase were inhibited significantly in the tests of 500 mg/kg and 1000 mg/kg (p<0.01). BBP at higher level interfered not only the energy supply process of aerobic and anaerobic glycolysis, but also the energy utilization in testis tissue. It is showed that the obstacles of energy metabolism caused by BBP associated with the damage of mice's germ cells.2. Lipid peroxidation of mice caused by BBPWith the increasement of BBP concentration, the content of GSH and MDA, and the activity of SOD had not changged in the serum of mice. But in the testis homogenate of mice compared to the control group, the content of GSH and the activity of SOD both dropped very significantly compared to the control group in all dose groups (p<0.01). It is showed that BBP could break the balance of oxidation-antioxidation system in testis, but the whole oxidation may be still at the level of antioxidant compensatory state in vivo. Lipid peroxidation is one possible toxic mechanism caused by BBP.3. BBP-induced DNA damage in mice spermsAccroding to comet assy, the damage index of DNA was increased significantly in all dose groups compared to that of control group (p<0.05 ), and indicated a remarkable dose-response relationship. Compared with the control group, tail DNA% and tail moment was increased very significantly in all dose groups(p<0.01), and indicated a remarkable dose-response relationship. All the results indicated that BBP may cause DNA damage in various degree, witch may be the functional mechanism of genotoxicity and reproduction toxicity induced by BBP.4. The effects of butyl benzyl phthalates on IL-1βand TNF-αmRNA expressions in the testis of miceRT-PCR was applied to examine the transcriptional changes of IL-1βand TNF-α. The results showed that IL-1βand TNF-αup-regulated slightly but without significance compared with control group in low-dose group. IL-1βand TNF-αboth up-regulated significantly in medium-dose and high-dose groups (p<0.05, p<0.01). These results suggested that BBP could increase the expressions of IL-1βand TNF-αin the testis of mice at the transcription level, witch may be the functional mechanism of male reproductive and developmental toxicity induced by BBP.