Objective To study the pneumotoxicity and hematotoxicity of PM2.5 and three lead compounds (PbSO4, PbCl2 and PbO)in rats.
Methods Seventy-eight SPF male Wistar rats were randomly divided into five groups including saline control group, fine particulate matter exposure group (low, medium and high exposure dose were 1.6, 8.0, 40.0 mg/kg& #183;bw respectively), lead sulfate exposure group, lead chloride exposure group and lead oxide exposure group. The low, medium and high exposure dose of lead exposure groups were 13.5, 67.5, 337.5 μg/kg& #183;bw respectively. Each dose group was exposed to a intra-tracheal instillation for three consecutive days, once per day. Twenty four hours after the last exposure, the rats were sacrificed and brochoalveolar lavage fluid (BALF)were collected and analyzed to measure the ingredients changeslactate dehydrogenase (LDH), alkaline phosphatase (AKP), acid phosphatase (ACP), albumin (ALB)and total protein (TP). Blood were collected to analyze the activity of δ-ALAD.
Results PM2.5 and three lead compounds all induced the increase of the percentage of neutrophils and reduce the percentage of macrophages in BALF. The content of LDH, AKP, ACP, TP and ALB in exposure groups were higher than those in control group with a significant dose-response correlation. Those effects induced by PM2.5 were more significant than lead compounds. On comparing with two other lead compounds, lead sulfate was the most significant one. Twenty four hours after the last exposure, δ-ALAD activity in blood was lowered as the lead dose increased. This effect induced by PM2.5 was more significant than lead compounds. The δ-ALAD activity reduced by lead sulfate was the most significant among all three lead compounds.
Conclusion Intratracheal instillation of PM2.5 and three lead compounds could resulted in pneumotoxicity and hematotoxicity in Wistar rats, compared with the same dose of lead-containing PM2.5, these lead compounds are less effective. The toxicity of these lead compounds is different from each other, and the toxic effects induced by lead sulfate are most significant.
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