Study Of Energy Metabolism Of Acute Laminitis In Dairy Cattle Induced By Oligofructose

Heifers laminitis is a kind of aseptic serous inflammation with high incidence of hoof leaf tissue,which can cause discomfort in cows' hoofs and decrease milk production.Now reported that many factors can lead to a cow laminitis.In recent years,research shows that the systemic inflammatory response(e.g.,endometritis,peritonitis,pleurisy),sepsis and endocrine disorder disease can lead to the occurrence of cow laminitis.In recent years,studies have found that the pathogenesis of dairy cow laminitis is relatively complex,with the overexpression of matrix metalloproteinase-2(MMPs-2)and matrix metalloproteinase-9(MMPs-9),and energy metabolism failure of digital laminar tissue as the main causes In this study,a lot of oligofructose were administered to establish a model of acute laminitis in dairy cow,and related indexes of serum metabolism in dairy cows digital laminar tissue,liver and muscle were detected to investigate the expression of blood metabolites and the changes of energy in digital laminar tissue after acute laminitis in cows.In this study,12 healthy non-pregnant Chinese Hesitate heifers were selected,with healthy hooves and no abnormal posture after clinical examination.The heifers were divided into two groups,including model group(OF group,n=6)and control group(CON group,n=6).Oligofructose was administered at 17 g/kg of WB for 0 h of the experiment,the previous three days were the adaptation period and the 0 h?72 h after the administered were the experiment period.The cows were monitored throughout the day during the adaptation period and the experiment period to ensure that the experiment could proceed smoothly.At 0 h,the OF group was given a large amount oligofructose,with a dose of 17 g/kg body weight,dissolved in 2 L/100 kg body weight clear water,and was directly gavage into the rumen through rumen cannula.The CON group was given the same volume clean water.During the first three days low dose-oligofructose administration,the OF group was given a 5% daily dose oligofructose as a transitional period,while the CON group was given the same volume water for the corresponding period.In-72 h and 0 h,and after serving after 6 h,12 h,18 h,24 h and 36 h,48 h,60 h,72 h,OF groups and CON group heifers in the jugular vein blood,used the method of ELISA detection in the serum insulin,triglycerides,total cholesterol,highdensity lipoprotein cholesterol,low density lipoprotein cholesterol,leptin,adiponectin and CD36,use glucose meter to detect the contents blood sugar.After 72 h the heifers were euthanasia and taken the liver,muscle and laminar tissues,for Western blot experiments and real time fluorescence quantitative PCR experiments,testing the energy of the liver,muscle and laminar tissues changes and glucose transport situation,specific indicators: sugar transporters 1 and 4(GLUT-1,GLUT-4),adenosine triphosphate kinase(AMPK)and related factors(P-AMPK,PPAR-?,PGC1-?,PEPCK).After large Oligofructose administration,OF group first limp at 6 h and all heifers at 24 h after ingestion.At the same time,the OF group heifers also showed diarrhea,higher body temperature and hoof temperature,hyper digital artery(toe),decreased rumen peristalsis and other symptoms.In OF group Blood glucose levels in the 6 h,12 h,and 18 h increased significantly compared with the CON group.After 18 h,blood glucose levels rapidly decreased and remained relatively stable,while OF group`s serum insulin levels decreased significantly at 6 h?12 h and 36 h?48 h.In OF group,total cholesterol and triglyceride decreased significantly at 6 h?72 h,LDL-C cholesterol decreased significantly at 24 h,decreased first and then increased in the same group,and HDL-C cholesterol decreased significantly at 6 h?12 h and 36 h?48 h.In OF group,serum leptin increased significantly at 12 h and increased significantly at 36 h compared with 0 h in OF group,while adiponectin and CD36 did not change significantly.After 72 h,all heifers were euthanasia and taken liver tissue after testing found that the concentration GLUT-1 gene in OF group`s liver decreased(P<0.05)but it protein expression no significant change,AMPK gene in OF group concentrations(P<0.05)and protein expression(P<0.01)levels significant increase,but the ratio of PAMPK/AMPK decreased(P<0.01),suggesting that the liver functional AMPK expression decreased result,but no obvious abnormal transport OF glucose in the liver.According to muscle tissue detection,OF group`s muscles AMPK gene concentration and protein expression has no obvious change,but P-AMPK protein expression decreased(P<0.01),at the same time,the ratio of PAMPK/AMPK decreased significantly(P<0.05),suggests that energy metabolism has changed in the muscle.OF group muscle GLUT-4 gene concentration(P<0.05)and protein expression levels(P<0.01)dropped significantly.This indicates that the expression of insulin-dependent glucose transporter receptors in muscle tissue is decreased,which is consistent with the decreasing trend of serum insulin content.The concentration of PPAR-? m RNA and PGC-1? m RNA in the digital laminar tissue increased(P<0.05),the concentration of GLUT-1 m RNA and the protein expression amount significant decreased(P<0.01),the AMPK m RNA concentration and protein expression amount not change significantly,but the protein expression of P-AMPK decreased significantly(P<0.01),and the PAMPK /AMPK ratio decreased significantly(P<0.01).The results showed that the expression of functional AMPK in the digital laminar tissues decreased after ingestion of large amounts of oligofructose,and the expression of non-insulin-dependent glucose transport receptor decreased.In summary:(1)The model of acute laminitis in dairy cattle established by oligofructose overload was reliable laboratory model for the study of cute laminitis in dairy cows.The experimental animals have a disorder of glycolipid metabolism,an increase in blood glucose,a decrease in insulin,and abnormal lipid metabolism,which may provide relevant indicators for the diagnosis of acute laminitis in dairy cattle.(2)In the process of acute laminitis,energy metabolism failure and abnormal glucose transport can occur in the digital laminar tissue of heifers,which may be one of the important reasons for the damage of the digital laminar tissue of heifers.