Research On Metabolomics Of Exercise Training In Inner Mongolian Horse Endurance

Endurance riding is an equestrian sport with long-history,and it is an entertainment in which people and animals cooperate.Mongolian horse is recognized as a distinct breed in China as well as one of the ancient horse breeds in the world with thousands of years of breeding history.They are also known for their endurance.In this paper,metabolics study of endurance training was carried out using 6 Mongolian horses and 6 hybrid horses as comparison groups.The training session lasted for two month and samples from each group were collected for both 15km and 30km distance training.Specifically,blood samples were collected at both before and after training,and after 45 minutes rest;muscle samples were collected at before and after training.Plasma and muscle samples metabolites were detected by 1H-NMR technology and metabolite classification analysis was performed using Chenomx NMR suit software.To identify the metabolic pathways and metabolites with significant difference before and after training the metabolic model was screened using PLS-DA and the metabolites were analyzed by one-dimensional variance analysis.Functional enrichment and KEGG Pathway analysis were carried out based on the identified metabolites.At last,the interaction network diagram was obtained,and metabolic pathways and diseases involved in during-exercise and after-exercise were identified.The main results are as follows:1.By analyzing the metabolites in plasma and muscles in Mongolian horse group,we found that 1)during 15km distance training Mongolian horses tended to switch on anaerobic metabolism to supply energy and showed lactic energy and sugar metabolism were more active.After training energy supply from fat was increased;2)during 30km distance training Mongolian horses tended to be in the aerobic metabolism of fat to provide energy,but the process of gluconeogenesis was enhanced,substances(i.e.carnitine,pantothenic acid,and betaine)associated with the consumption of fatty acid metabolism were increased.After training,the immune pressure was increased dramatically.These results indicate that fat reserve,the production and clearance of lactic acid are of great significance for Mongolian horse endurance training.2.By analyzing the metabolites in plasma and muscles in hybrid horse group,we found that 1)during 15km distance training hybrids tended to be in the aerobic metabolism to provide energy,and lactate energy and glucose metabolism were more active.After training glycolysis kept providing energy;2)during 30km distance training both glycolysis and lipid aerobic metabolism tended to provide energy to the hybrids and immune pressure was increased significantly after the training.Glycolysis was relatively active during the 15km as well as 30km training,at the same time,the hybrids showed the ability of getting rid of lactic acid.The results suggested that the production and clearance of lactic acid are essential in the hybrids endurance training.3.By comparing the metabolites in plasma and muscles between Mongolian horses and hybrids,before training glycometabolism was more active in hybrids,however,metabolism of fatty acids was the source of energy in Mongolian horse.During the training,the Mongolian horses showed the ability of fat mobilization that is essential in the long-distance training,however,the hybrids showed the ability of lactic acid tolerance and metabolism which is required for short distance racing.These results suggested that Mongolian horses are suitable to be bred for long distance racing.4.To obtain 15km distance exercise associated metabolic pathways,the analysis of metabolic pathways and disease related enrichment was performed based upon the identified metabolites from both Mongolian horse and hybrids.The identified pathways during the training were mainly related to glycolysis or gluconeogenesis,synthesis and degradation of ketones,citrate cycle,valine,degradation of leucine and isoleucine,valine,biosynthesis of leucine and isoleucine,metabolism of taurine and taurine,methane metabolism,D-glutamine and D-glutamic acid metabolism.The pathways after exercise were associated to the possibility of material metabolism abnormality,oxidative stress,various discomfort,inflammatory disease,muscle lysis,nerve disorder,mitochondrial encephalopathy lactic acid stroke,anaerobic disease,heart failure,myocardial infarction,myocardial injury,asphyxia,severe convulsion or cardiogenic shock,adrenocortical dysfunction.These suggested that supplements and getting rests are needed to the horses after long distance training.