Dissertation
Dissertation > Agricultural Sciences > Livestock, animal medicine,hunting,silkworm,bee > Animal Medicine ( Veterinary Medicine) > Livestock, poultry, wildlife diseases > Livestock > Dog

GC-MS Analysis of Endogenous Metabolites in Plasma of Police Dog after Aflatoxicosis

Author LiuYaLing
Tutor WuDeHua;HuangKeHe
School Nanjing Agricultural College
Course Clinical Veterinary Medicine
Keywords endogenous metabolites in plasma liver injury police dog GC-MS AF PCA
CLC S858.292
Type Master's thesis
Year 2009
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Afiatoxins are a structurally similar group of naturally occurring, harmful fungal secondary metabolites that are produced by Aspergillus flavus and Aspergillus parasiticus, and widely found in moldy animal feed. Aflatoxin Bl is the most toxic of the aflatoxins and is a potent liver carcinogen. Animals are very sensitive to the aflatoxins and can be induced liver injury largely when they have eaten the contaminated food with aflatoxin. However the liver plays a central role in the metabolism of carbohydrates, fatty acids, amino acids and so on. It undertakes most of the synthesis, decomposition, transformation, excretion and other metabolic processes. Once damaged, it would lead to substance metabolism disorder. Therefore, study of the aflatoxicosis is very important from a metabolic point. Metabonomics can reflect the relationships between the organism function and concentration of endogenous and exogenous metabolites which in the cells and body fluids, and has been widely used in the research of pharmacology and biological sciences. Gas chromatography-mass spectrometry (GC-MS) is a better and mature technique with searchable standard database, excellent separating, qualitative abilities with a high sensitivity and easy operation, which facilitates the identification of metabolites. Thus GC-MS considered as an ideal tool is suitable for metabonomics analysis. At present the study of aflatoxicosis of police dog based on metabonomics hasn’t been reported at home and abroad. So in this thesis, the chemical derivatization was carried out, and after that, a GC-MS approach was established for characterizing the metabolite profiles of the plasma from the aflatoxicosis canine. Then we studied the changes of metabolies in plasma through the method established. The main content of this study is presented as follows:1. A GC-MS analytical method established for endogenous metabolites in plasma of police dog A reliable GC-MS analytical method was established to obtain the metabolite profiles of plasma of healthy police dog. The procedures of sample preparation and chromatographic conditions were optimized, and validation of the method was carried out, then the excellent GC-MS analytical conditions with large capacity peak and high separation were obtained. The results showed that GC-MS analytical method was stable and reliable. It was capable to describe the biochemical composition of plasma samples.2. Analysis of endogenous metabolites in plasma of police dog by GC-MSA Gas chromatograph-Mass Spectrometry based on methodology was developed to investigate the endogenous metabolites in police dog’s plasma of German shepherd, English Springer Spaniel and Labrador Retriever. The results showed that there were 38 commensal endogenous metabolites in canine plasma. The major commensal metabolites were low molecular weight compounds include amino acids, fatty acids, carbohydrates and so on. Through the analysis of the 38 commensal endogenous metabolites, we found the concentrations of some metabolites among the three species there were differences.3. Metabonomic Study of plasma in canine after aflatoxicosis by GC-MSA metabonomic study was developed to investigate the hepatic injury of canine which was induced by aflatoxin. Gas chromatography -mass spectrometry (GC-MS) was used to analyze the canine metabonome in plasma after aflatoxicosis. NIST mass spectral database was used for the rapid identification of endogenous metabolites of plasma. Then principal component analysis (PCA) was deployed for the changes of endogenous metabolites in plasma of canine after canine aflatoxicosis. The results presented that metabolite profiles in plasma appeared corresponding changes with the various time lapse when the Labrador Retriever occurred aflatoxin poisoning. The increased concentrations of several amino acids(L-Isoleucine, Glycine, L-Threonine and so on), as well as the decreased concentrations of glucose, L-Valine, cholesterol and some free fatty acids(for example, Hexadecanoic Acid and Octadecanoic Acid) in plasma, could be considered as the response metabolites of AF induced liver injure. And there were some relationships between endogenous metabolites changes and the degree of liver damage. The changes of endogenous metabolites levels in plasma can indirectly reveal the extent of aflatoxicosis in canine. The changing tendencies of the metabolite profiles were conformity with the results of blood biochemical parameters. It can be seen that GC-MS based on metabonomic studies could be better reflect the whole status of metabolism in bio-systems. And PCA can be also introduced for the pattern recognition of canine metabonome in plasma. All these would be to hope a new method to diagnose aflatoxicosis.

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