Distribution of cadmium in mice after exposure to cadmium via drinking water
OBJECTIVE:This study aimed to elucidate the distribution,accumulation and toxicity of cadmium in the blood,esophagus,liver,and kidneys of mice following subchronic exposure of cadmium in drinking water.METHODS:For this study,27 pathogen-free(SPF)-grade C57BL/6J mice were randomly assigned to a control,low-dose(10 mg/kg CdCl2),and high-dose groups(75 mg/kg CdCl2).The control group received standard feed and double-distilled water,while the exposed groups were given standard feed and a solution containing the corresponding concentration of CdCl2.The low-dose group was exposed to cadmium for 8,12,16,and 20 weeks,and the high-dose group for 16 weeks,with three mice per time point.Whole blood was collected from the orbital cavity of mice of the control group at 8 and 12 weeks,the low-dose group at 8,16,and 20 weeks,and the high-dose group at 16 weeks.Mice were sacrificed according to the experimental time points,and esophageal,liver,and kidney tissues were collected.Cadmium levels were measured using inductively coupled plasma mass spectrometry(ICP-MS).RESULTS:Blood cadmium levels in the treated groups were significantly higher than in the control group(P＜0.01).The blood cadmium levels in the low-dose group were significantly increased compared to the control(P＜0.01),but there was no statistically significant difference among the different exposure time points within the group(P＞0.05).At the 16-week time point,the blood cadmium levels in the high-dose group were significantly higher than in the low-dose group(P＜0.01).The esophageal cadmium concentration in the low-dose group was higher than in the control group at all exposure time points(P＜0.05 or P＜0.01),with the highest concentration at 20 weeks(67.7 μg/L),which was statistically significant compared to 8 weeks(44.0 μg/L)and 12 weeks(35.2 μg/L)(P＜0.05 or P＜0.01).The esophageal cadmium concentration in the high-dose group(129.2 μg/L)at 16 weeks was significantly higher than in the low-dose group(47.9 μg/L,P＜0.01).In the low-dose group,cadmium concentrations in liver and kidney tissues increased from 12-16 weeks and 8-16 weeks,respectively,compared to the control group(P＜0.05 or P＜0.01),reaching a peak at 16 weeks(P＜0.01)before declining.At 16 weeks,there were statistically significant differences in the cadmium concentrations of liver and kidney tissues among all dose groups,with the highest concentrations in the high-dose group(P＜0.01).Cadmium levels were quantifiable in the blood,esophagus,liver,and kidneys of both control and cadmium-treated groups,with the highest to lowest order of cadmium content being kidney＞liver＞esophagus＞blood.CONCLUSION:Dietary cadmium exposure resulted in the accumulation of cadmium in the blood,esophagus,liver,and kidney of mice,exhibiting a definite time-and dose-dependent effect.
cadmiummiceaccumulationinductively coupled plasma mass spectrometryesophagus
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维普
