Metabolism Studies On Liver And Brain In Rats Exposed To Benzo(a) Pyrene And Atmospheric Fine Particulate Matter

Objective:To study the metabolic changes of liver and brain in rats exposed to benzo（a）pyrene and atmospheric PM_2.5,using nuclear magnetic resonance（NMR）,analysis of its involved in the metabolic pathway,to investigate the possible mechanism of benzo（a）pyrene and PM_2.5 exposure to rat liver and brain injury,to find possible early biomarkers,to prevent the damage of benzo（a）pyrene and PM_2.5 to human Provide a new theoretical basis.Methods:Part I: 24 healthy male SD rats were selected,weighing about 180-200 g,were randomly divided into four groups,（each 6）: solvent control group（olive oil）,low dose group（1mg / kg）,middle dose group(_2.5mg / kg)and high dose group（6.25 mg / kg）.Three groups was injected intraperitoneally with benzo（a）pyrene,and the control group was treated with intraperitoneal injection of olive oil,once a day,weekly continuous injection of 5 days,exposure to 3 weeks.Abdominal aorta blood collection,anatomy of the liver and brain,and do pathological examination and metabolic detection.Part II: the use of TH-1000 C II large flow of air particulate sampler for sampling,heating period will be placed in the traffic flow of large traffic junctions,access to atmospheric PM_2.5 particles.36 healthy male SD rats were randomly divided into 6 groups（each 6）.Control group（saline 1.5ml / kg body weight）,PM_2.5 low dose group（1.5mg / kg body weight）,PM_2.5 middle dose group（6mg / kg body weight）,PM_2.5 high dose group（24mg / kg body weight）,PM_2.5 water-soluble component group（24 mg / kg body weight）and PM_2.5 water-insoluble ingredient group（24 mg / kg body mass）.Rat aerosol lung administration kit was used and the rats were treated with trachea atomization for 5 times.36 healthy male SD rats were randomly divided into 6 groups: 0 days,1 day,3 days,5 days,7 days,9 days,6 rats in each group.The rats were treated with rat aerosol lung administration kit,for the next day exposure,exposure dose of 24 mg / kg body weight.Abdominal aorta blood collection,anatomy of the liver and brain,and do pathological examination and metabolic detection.The liver and brain tissues were examined by BRUKER AVANCE III nuclear magnetic resonance（¹H）detection platform.Mest Re Nova software,SIMCA-P 11.0software and SPSS17.0 software were used to find out the difference metabolites.Metabo Analyst3.0（http://metaboanalyst.ca）combined with HMDB（Human Metabolome Database）,KEGG（Kyoto Encyclopedia of Genes and Genomes）and other databases on the relevant metabolic pathway involved in the preliminary analysis.Results:Part 1: Study on liver and brain metabolites in rats exposed to benzo（a）pyrene Pathological results:In the middle dose group,the liver cell fat-like changes,in the high dose group,the liver cell fat-like changes,the portal area lymphocyte infiltration,and no pathological changes were observed in the brain tissues in each group.Liver metabolomics results: The differential metabolites of VIP> 1 were 26,28 and 24,respectively,by low,medium and high dose groups.The leucine/isoleucine,valine,acetate,oxidized glutathione,lactic acid,glycerol phosphocholine,arginine and glycoprotein increased with the increase of dose,glutamic acid/glutamate,betaine,taurine,alpha-glucose,glycogen,lysine,succinic acid,glutathione,methionine,aspartic acid,glycerol,hippuric acid decreased with the increase of dose.Compared with the control group,in the low dose group,leucine/isoleucine,alanine,acetate,oxidized glutathione,glycine,valine,arginine,3-hydroxybutyl acid were significantly increased,glutamic acid/glutamine,betaine,taurine,alpha-glucose,beta-glucose,glycogen,lysine,succinic acid,glutathione,methionine,aspartic acid,glycerol,hippuric acid and acetoacetate were significantly decreased（P<0.05）.In the middle dose group,leucine/isoleucine,alanine,acetate,oxidized glutathione,glycine,valine,glycerol phosphate,creatine,lactate,triglyceride,glycoprotein were significantly increased,glutamic acid/glutamine,betaine,taurine,alpha-glucose,beta-glucose,glycogen,lysine,succinic acid,glutathione,methionine,aspartic acid,glycerol,hippuric acid and acetoacetate were significantly decreased（P<0.05）.In the high dose group,leucine/isoleucine,alanine,acetate,oxidized glutathione,glycine,arginine and glycerophosphorylcholine were significantly increased,glutamic acid/glutamine,betaine,taurine,alpha-glucose,beta-glucose,glycogen,lysine,succinic acid,glutathione,methionine,aspartic acid,glycerol,hippuric acid and acetoacetate were significantly decreased（P<0.05）.A comprehensive analysis of metabolic pathways revealed that exposure to benzo（a）pyrene could lead to valine,leucine and isoleucine biosynthesis,ketone synthesis and degradation,glycine,serine and threonine metabolism,alanine,aspartic acid and glutamic acid metabolism,glycerol metabolism,taurine and taurine metabolism in rat liver path changes.Brain metabolomics results:The differential metabolites of VIP> 1 were 18,21 and 19,respectively,by low,medium and high dose groups.The 2-amino-ethanedioic acid and malic acid increased with the increase of dose,leucine/isoleucine,lactic acid,N-acetyl glycoprotein,glycoprotein,proline,pyruvate,citric acid,creatine,phosphorylcholine,betaine,inositol,taurine,glycerol,glutamine/glutamate,lysine,succinic acid decreased with the increase of dose.Compared with the control group,in the low dose group,alanine were significantly increased,proline,pyruvate,citric acid,betaine,lysine and glycerophosphorylcholine were significantly decreased（P<0.05）.In the middle dose group,malic acid and N-acetylaspartate were significantly increased,proline,pyruvate,citric acid,betaine,lysine,N-acetylglucoprotein,glycoprotein,creatine,phosphorylcholine,inositol,glycerol,glutamine/glutamate,succinic acid,leucine/isoleucine were significantly decreased（P<0.05）.In the high dose group,2-amino-ethanedioic acid were significantly increased,proline,pyruvate,citric acid,betaine,lysine,N-acetylglucoprotein,glycoprotein,creatine,phosphorylcholine,inositol,glycerol,glutamine/glutamate,succinic acid,lactic acid,taurine and triglyceride were significantly decreased（P<0.05）.A comprehensive analysis of metabolic pathways revealed that exposure to benzo（a）pyrene could lead to pyruvate metabolism,citrate cycling,glycolysis or gluconeogenesis,glycerol metabolism,taurine and taurine metabolism in rat brain path changes.Part II: Study on liver and brain metabolites in rats with atmospheric PM_2.5 exposure Pathological results: Low dose group of regional lymphocyte infiltration,middle dose group of liver cell fat-like changes,high dose group of liver cell fat-like changes,inflammatory exudation,water soluble group of liver cell fat-like changes,non-water soluble group of lymphocytes infiltration,liver cell fat-like changes;and no pathological changes were observed in the brain tissues in each group.Liver metabolomics results:The differential metabolites of VIP> 1 were 23,25 and 27,respectively,by low,medium and high dose groups.The LDL/VLDL,3-hydroxybutyric acid,acetate,creatine,glycine and glycerophosphorylcholine increased with the increase of dose,valine,glutamine/glutamate,choline,betaine,taurine,beta-glucose,alpha-glucose,glycogen,lysine,succinic acid,glutathione,methionine,aspartate and glycerol decreased with the increase of dose.Compared with the control group,in the low dose group,glycine and lactic acid were significantly increased,glycogen,methionine,glycerol,acetoacetic acid and succinic acid were significantly decreased（P<0.05）.In the middle dose group,glycine,lactate,LDL/VLDL and 3-hydroxybutyric acid were significantly increased,glycine,methionine,glycerol,acetoacetic acid,succinic acid,glutamine/glutamate,choline,betaine,taurine,beta-glucose,lysine,glutathione,aspartic acid,valine were significantly decreased（P<0.05）.In the high dose group,LDL/VLDL,3-hydroxybutyric acid,acetate,creatine and glycerophosphorylcholine were significantly increased,glycine,methionine,glycerol,acetoacetic acid,LDL/VLDL,3-hydroxybutyric acid,glutamine/glutamate,choline,betaine,taurine,beta-glucose,lysine,glutathione,aspartate and α-glucose were significantly decreased（P<0.05）.A comprehensive analysis of metabolic pathways revealed that exposure to atmospheric PM_2.5 could lead to ketone synthesis and degradation,alanine,aspartic acid and glutamic acid metabolism,taurine and sub-taurine metabolism,glutathione metabolism in rat liver path changes.Time effect relationship results,The differential metabolites of VIP> 1 were 25,24,19,21 and 27,respectively,by 1,3,5,7,and 9 days groups.Compared with the 0 day group,3-hydroxybutyric acid,phosphorylcholine,leucine / isoleucine,proline,glycine,acetate,alanine,acetoacetic acid,hippuric acid,inositol and creatine were significantly increased,taurine,betaine,choline,glutathione,aspartic acid,α-glucose,β-glucose,glycogen,acetoacetic acid,methionine,glycerol,glutamate,lactic acid,valine,amber acid,hippuric acid,oxidized glutathione and inositol were significantly decreased（P<0.05）.A comprehensive analysis of metabolic pathways revealed that exposure to atmospheric PM_2.5 could lead to ketone synthesis and degradation,alanine,aspartic acid and glutamic acid metabolism,taurine and sub-taurine metabolism,glutathione metabolism in rat liver path changes.Different component results,The differential metabolites of VIP> 1 were 23 and 25,respectively,by water soluble component groups and non-water soluble component groups.Compared with the control group,in the water soluble component group,inositol were significantly increased,betaine,taurine,glycerol,glutamate,glutathione,aspartic acid,α-glucose,lactic acid and β-glucose were significantly decreased（P<0.05）.Metabolic pathway analysis showed that water soluble components could lead to liver alanine,aspartic acid and glutamic acid metabolism,taurine and sub-taurine metabolism,glutathione metabolism changes in these metabolic pathways.In the non-water soluble component group,inositol,leucine/isoleucine,3-hydroxybutyric acid,phosphocholine and glycine were significantly increased,betaine,taurine,glycerol,glutamate,glutathione,aspartic acid,α-glucose,acetoacetic acid,methionine and glycogen were significantly decreased（P<0.05）.Metabolic pathway analysis showed that non-water soluble components could lead to liver ketone synthesis and degradation,alanine,aspartic acid and glutamic acid metabolism,taurine and sub-taurine metabolism,glutathione metabolism changes in these metabolic pathways.Brain metabolomics results:The differential metabolites of VIP> 1 were 16,16 and 13,respectively,by low,medium and high dose groups.The lactic acid,γ-aminobutyric acid,citric acid,phosphocholine,betaine,inositol and taurine decreased with the increase of dose.Compared with the control group,in the low dose group,γ-aminobutyric acid,taurine and N-acetyl-glycoprotein were significantly decreased（P<0.05）.In the middle dose group,γ-aminobutyric acid,taurine,lactic acid,phosphocholine,betaine and inositol were significantly decreased（P<0.05）.In the high dose group,γ-aminobutyric acid,taurine,N-acetyl-glycoprotein,lactic acid and citric acid were significantly decreased（P<0.05）.A comprehensive analysis of metabolic pathways revealed that exposure to atmospheric PM_2.5 could lead to glycerol metabolism,pyruvate metabolism,citric acid cycle,glycolysis or glycogenogenesis in rat brain path changes.Time effect relationship results,The differential metabolites of VIP> 1 were 14,17,18,17 and 16,respectively,by 1,3,5,7,and 9 days groups.Compared with the 0 day group,lactic acid,glutamate,γ-aminobutyric acid,pyruvate,citric acid,lysine,betaine,taurine,triglyceride and creatine were significantly decreased（P<0.05）.A comprehensive analysis of metabolic pathways revealed that exposure to atmospheric PM_2.5 could lead to glycerol metabolism,pyruvate metabolism,citric acid cycle,glycolysis or glycogenogenesis in rat brain path changes.Different component results,The differential metabolites of VIP> 1 were 20 and 18,respectively,by water soluble component groups and non-water soluble component groups.Compared with the control group,in the water soluble component group,betaine and γ-aminobutyric acid were significantly decreased（P<0.05）.Metabolic pathway analysis showed that water soluble components could lead to brain glycerol metabolism,pyruvate metabolism,citric acid cycle,glycolysis or glycogenogenesis changes in these metabolic pathways.In the non-water soluble component group,betaine,3-hydroxybutyric acid,lactic acid,N-acetyl-glycoprotein,glycoprotein,oxidized glutathione,proline,pyruvate,citric acid,creatine,glycerophosphorylcholine,taurine,lysine,succinic acid,triglyceride were significantly decreased（P<0.05）.Metabolic pathway analysis showed that non-water soluble components could lead to brain glycerol metabolism,pyruvate metabolism,citric acid cycle in these metabolic pathways.Conclusion:1.B（a）P,atmospheric PM_2.5 after short-term exposure to rats,rat liver and brain showed a small molecular metabolic profile changes.2.B（a）P short-term exposure can cause biodegradation of valine,leucine and isoleucine,ketone synthesis and degradation,glycine,serine and threonine metabolism,alanine,aspartate glutamic acid and glutamic acid metabolism,glycerol metabolism,taurine and taurine metabolism of these metabolic pathways changes in the liver,reaction of B（a）P caused by amino acid metabolism,lipid metabolism,oxidative stress disorder.B（a）P short-term exposure can cause pyruvate metabolism,citrate cycle,glycolysis or gluconeogenesis,glycerol metabolism,taurine and taurine metabolism of these metabolic pathways changes in the brain,reaction of B（a）P caused by energy metabolism,lipid metabolism,oxidative stress disorder.These disorders may be related to the mechanism of liver and brain damage in rats.3.Atmospheric PM_2.5 short-term exposure can cause ketone synthesis and degradation,alanine,aspartic acid and glutamic acid metabolism,taurine and sub-taurine metabolism,glutathione metabolism of these metabolic pathways changes in the liver,reaction of PM_2.5 caused by amino acid metabolism,oxidative stress disorder,water soluble ingredients,non-water soluble ingredients can cause alanine,aspartic acid and glutamic acid metabolism,taurine and sub-taurine metabolism,glutathione metabolism of these metabolic pathways changes in the liver,non-water soluble ingredients can also cause ketone synthesis and degradation of metabolic pathways changes in the liver,different components also caused by amino acid metabolism,oxidative stress disorder.Atmospheric PM_2.5 short-term exposure can cause glycerol metabolism,pyruvate metabolism,citric acid cycle,glycolysis or glycogenogenesis of these metabolic pathways changes in the brain,reaction of PM_2.5 caused by lipid metabolism,energy metabolism disorder,water soluble ingredients,non-water soluble ingredients can cause glycerol metabolism,pyruvate metabolism,citric acid cycle of these metabolic pathways changes in the brain,water soluble ingredients can also cause glycolysis or glycogenogenesis of metabolic pathways changes in the brain,different components also caused by lipid metabolism,energy metabolism disorder.These disorders may be related to the mechanism of liver and brain damage in rats.