| Background:Cadmium is a highly toxic and accumulative pollutant that affects human health,especially lipid metabolism.At present,most studies have clarified the effect of cadmium on lipid metabolism from the perspective of characteristic indicators,and rarely explore it from the perspective of histology.Therefore,this topic is proposed to use cadmium chloride as the research object,using lipid histology methods from the molecular level to explore the toxic effects of cadmium on lipid metabolism in rats,to find out the potential lipid biomarkers associated with cadmium exposure,to explore cadmium on the body's lipid metabolism mechanism.Method:1.After one week of adaptation,24 6-week-old SPF-grade SD rats were randomly divided into 4 groups,namely,blank control group(negative control group),low-dose cadmium chloride group(1.375 mg/kg),medium-dose cadmium chloride group(5.5 mg/kg),high-dose cadmium chloride group(22 mg/kg),the subjects were Cd Cl2 solution,with ultrapure water to be used to make the above three doses.The experimental period is 14 days.During feeding,daily stomach filling,free drinking water diet.Blood is collected on the 14 th day.After feeding,the weight change,organ coefficient,blood cadmium accumulation and lipid metabolism index were measured.2.By using high-resolution mass spectrometry technology,the serum and liver nontargeted lipid group detection methods were established,and the data were processed using multiple statistical analysis methods to observe the differences in lipid metabolism between the cadmium exposure group and the control group.3.Screening for potentially significant difference metabolites in rat serum and liver after short-term repeated exposure of cadmium chloride,identification of potential significant difference metabolites after screening according to the database,and correlation analysis and pathway analysis of identified potentially different compounds.Explore the similarities and differences between potential lipid metabolites in serum and liver tissue and the connections between their pathways.Results:1.Effect of cadmium on physiological activity and lipid characteristics in ratsAfter the 14-day cadmium exposure experiment in SD rats,the weight of SD rats in all groups increased,the weight of rats in the dosage group was lower than that of the control group,and the liver organ index of rats decreased,and the kidney organ index increased significantly(P<0.05),indicating that cadmium intake had a certain effect on physiological activities in SD rats.Using ICP-MS to determine the content of cadmium in blood and major organs,it was found that cadmium was mainly accumulated in the liver and kidneys,the heart,lungs and spleen were less abundant and hardly accumulated in the blood;With the increase of cadmium exposure,the content of TG in the high-dose cadmium exposure group(22mg/kg)and the medium-dose cadmium exposure group(5.5mg/kg)was significantly lower than that in the control group(P<0.05)and was negatively correlated The LDC content in the serum(22mg/kg)was significantly lower than in the control group(P<0.05),while the TC,HDC,ACC and MDH were not significantly different in all cadmium exposure groups and control groups(P>0.05).2.Analysis of lipid metabolism profile in serum-liver tissue in laboratory ratsIn both the serum and liver,the high dose(22 mg/kg)cadmium exposure group and the control group OPLS-DA score chart were significantly separated,indicating that the lipid metabolite content between the two groups changed,that is,after cadmium exposure,lipid metabolism disorders occurred in rats.3.Screening identification of potential differences and pathway analysisA total of 42 significant lipid potential differential metabolites were screened in rat serum,mainly triglycerides and glycerin phospholipids,and 11 significant lipid potential differential metabolites were screened in liver tissue,mainly glycerin phospholipids and lipids.Screening hemorrhagics-The liver has a total of 3 types of potential lipid difference metabolites,respectively PE-NMe2(18:2(9Z,12Z)/18:0),PI(18:0/20:4(5Z,8Z,11 Z,14Z)and SM(d18:1/22:0).Finally,it is concluded that cadmium causes changes in lipid metabolism in rats by the metabolism of lipids and glycerin phospholipid metabolism.Conclusion:1.As the dose increased,cadmium levels increased in rats and were mainly distributed in the liver and kidneys,and triglycerides levels decreased significantly in rats.2.Three serum-tissue common difference metabolites were significantly increased,combined with pathway analysis,indicating that cadmium exposure to rats glycerin phospholipid metabolism and lipid metabolism significantly disordered. |
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