Study On Formaldehyde-induced DPC In The Liver Of Mice

Recently, the problem of indoor air pollution caused by decoration and fitment are following with interests. Because of its characteristics of extensive sources, serious toxicities, high-level pollution and long-term duration, formaldehyde is considered to be one of the most common pollutants. And the study of formaldehyde has become a hot and difficult spot of the environmental and hygienical fields. Our study aims to further calibrate the DNA damage and reproductive genotoxicity and mechanism of FA inhalation under different level, and to find biomarkers which can be earlier and more conveniently to detect the damage induced by FA.1. The effect of gaseous FA-induced DPC and its repair process in mice liverSPF-class Kun-Ming male mice were exposed to gaseous formaldehyde at different concentrations (0.5mg/m~3, 1.0mg/m~3 and 3mg/m~3) and DPC content was detected by KC1-SDS assay. The result showed there was no significant difference in the DPC coefficient between the group treated with 0.5mg/m~3 of FA and the control group. While, there was a significant difference between the groups treated with 1.0 and 3.0mg/m~3 of FA and the control group (P<0.01). The results showed gaseous FA could not induce DPC at low concentration but could induce DPC significantly at high concentrations, and the concentrations of FA and the DPC coefficient had obviously dose-dependent relationship. DPC induced by gaseous formaldehyde at 3.0 mg/m~3 can be removed within 12 hours.2. The effect of liquid FA-induced DPC and its repair process in HepG 2 cellsHepG 2 cells was exposed to liquid FA with different concentrations and DPC content was detected by KC1-SDS assay. The result showed there was no significant difference in the DPC coefficient between the group treated with 25μmol/L, 50μmol/L of FA and the control group. While, there was a significant difference between the groups treated with 75μmol/L and above 75μmol/L of FA and the control group (P<0.01). The results showed liquid FA could not induce DPC at low concentrations but could induce DPC significantly at high concentrations, and the concentrations of FA and the DPC coefficient had obviously dose-dependent relationship. DPC induced by liquidformaldehyde at 75 jumol/L can be removed significantly after 18 and 24 hours, but not the case after 6 and 12 hours.3. The effect of liquid FA-induced DPC and its repair process in mice liverSPF-class Kun-Ming male mice were injected by liquid formaldehyde at different concentrations (0.2mg/kg> 2mg/kg and 20mg/kg) and DPC content was detected by KC1-SDS assay at different time. The results showed DPC induced by liquid formaldehyde can be removed significantly after 18 and 24 hours.4. The effect of FA-induced DSSB in mice liverSPF-class Kun-Ming male mice were exposed to gaseous formaldehyde at different concentrations (0.5mg/m > l.Omg/m and 3mg/m ) and FA-induced DSSB in mice liver cells was detected by SCGE. The result showed that FA could induce DSSB significantly in mice liver after exposure to 0.5 and 1.0mg/m3 gaseous FA (0.5 mg/ra3, p<0.01;1.0mg/m3, p<0.01). As FA concentrations increased, tail movement of comet abated (P<0.01) obviously, which indicated that DSSB decreased markedly and FA might induce DNA crosslinks, including DDC and DPC. Importantly, by combining these results with the results of KC1-SDS assay we could quantitatively determine that FA probably induced DPC at 3.0mg/m3. It was concluded that FA mainly induced DSSB at 0.5 and 1.0mg/m3, and mainly induced DPC at 3.0 mg/m3. This study showed FA could induce DSSB significantly at low concentrations, while at high levels it mainly induced DPC.