AGR 322 Exam 5

• Liver

  Body's filter for blood
• Liver enzymes

  • Induced or leakage
  • Hepatocyte damage
  • Some liver-specific, some all over
• ALT


  Leaks from damaged hepatocytes
• SDH


  • Very fast half life
  • Liver specific in large animals
• GLDH


  Liver specific in birds
• ALKP


  • Not liver specific
  • Needs calcium- don't use EDTA plasma
  • Can indicate cholestasis
• GGT


  • Not liver specific
  • Indicates cholestasis
  • Can indicate hemolysis
• AST


  Not liver specific
• Functional liver tests


  • Total protein
  • Albumin
  • Ammonia (liver converts ammonia to BUN)
  • Bile acids
  • Bilirubin
  • Cholesterol
  • Coagulation tests
• Liver damage enzymes

  • ALT: small animals and monkeys
  • AST: RBCs, muscles, kidney, pancreas
  • GLDH: ruminants, avian
  • SD: breaks down <2 hours, highly liver specific in horses and cows
• Cholestasis

  • ALKP: osteoblasts, chondroblasts, intestines and placenta
  • GGT: large animals and birds, kidneys, mammary tissue, pancreas, intestines, and muscle, only hepatic GGT is in serum
• Other liver tests


  • Ammonia NH3
  • Bile acids
  • Portosystemic shunts
  • Clotting tests
  • Prothrombin time
• Bilirubin


  • Function test
  • Breakdown product of hemoglobin
  • Yellow plasma, serum, and mucous membranes
  • Porphyrin > biliverdin > bilirubin
  • Direct and total bilirubin is measured in blood, indirect is calculated
  • Falsely elevated by lipemia and hemolysis
  • Light sensitive
• Ammonia


  • False elevations occur with prolonged delays
  • Fast at least 8 hours prior to sampling
  • Heparin or EDTA plasma with no ammonia
  • Notify lab of intent to submit sample
  • Place samples in ice bath
  • Separate from cells immediately post collection
  • Freeze of get to lab within 3 hours of collection
  • Minimize exposure to air (use sealed vacutainer everything)
• Bile acids


  • Cholestasis, liver disease, portosystemic shunt, or hyperadrenocorticism
  • Fasted and postprandial in dog and cat
  • Random sample in horses
  • False decrease with hemolysis
  • False increase with lipemia
  • 2 hours post meal
  • Plain red top tubes
• Coagulation tests


  • PT, PTT, TCT, Factor VII-XII
  • Protein C, antithrombin, fibrinogen
  • Avoid: clots, lipemia, hemolysis
  • Fill: completely fill citrate tube
  • Centrifuge and separate
  • Freeze for lab submission
  • Interferes: use plastic tubes, glass tubes interfere with some coag tests
• Proteins


  • ALB
  • GLOB
  • Gamma plasma cells
  • Fibrinogen
  • C-reactive protein
  • Serum amyloid A
  • Troponin
• Hypoproteinemia/hypoalbuminemia/hypoglobulinemia


  PLE, Parasitism, Hemorrhage, IBD, Malnutrition, Liver or kidney disease
• Hyperproteinemia/hyperalbuminemia/hypoglobulinemia


  Dehydration, Hemolysis, Lipemia, Acute blood loss, Inflammation
• Hyperfibrinogenemia


  Inflammation, Neoplasia
• Hypofibrinogenemia


  Disseminated intravascular coagulation (DIC)
• Thrombin test


  Fibrin degradation products (FDPs)
• 1. reactive protein


  • Emergency test
  • Acute phase protein
  • Produced by liver
  • Inflammation
  • Rises in 4 hours
  • Cleared quickly
  • Dogs, pigs, horses
• Troponin


  • Protein of the heart
  • Found in microfibrils
  • Breed differences
• Other globulin proteins


  • Serum Amyloid A (acute phase protein)
  • Complement components (C3)
  • Haptoglobin (acute phase protein)
  • Hemopexin
  • Ceruloplasmin (acute phase protein)
  • Protein C
  • Antithrombin
  • Beta globulins: transferrin, ferritin, complement
• Plasma lipids/lipoproteins


  • Cholesterol
  • Cholesterol esters
  • Triglycerides
  • Phospholipids
  • Nonesterified (free) fatty acids
• Lipoproteins


  • Produced by liver
  • Elevations: renal disease, diabetes, cholestasis, pancreatitis, hypothyroidism, hypoadrenocorticism (cushings)
  • HDL: alpha 1
  • LDL: beta 2
  • VLDL: alpha 2
• Hyperchylomicronemia/triglyceridemia


  • Elevated with triglycerides
  • Pancreatitis: dogs
  • Xanthomas: cats
  • Yellow nodules of cholesterol
  • Mini schnauzers, middle aged and older animals
  • Diabetes mellitus
• Glucose/ketones/lactate


  • Fasted animals utilize stored glucose in liver
  • Insulin increases cellular uptake of glucose (muscle, fat, liver)
  • hyperglycemia/hypoglycemia
  • Fasting, separate serum/plasma, avoid lipemia
  • Glucosuria
  • Sodium fluoride=preservative
  • Lactate dehydrogenase (LDH)=colic
  • Fructosamine
• Fructosamine


  • Glycated serum proteins
  • Albumin and glucose
  • Weekly perspective of increase
  • Eliminates glucose from excitement or stress (cats)
• Stress corticosteroids


  • Increased WBC
  • Increased mature neutrophils
  • Increased lymphocytes
  • Increased monocytes
  • Decreased eosinophils
• Protein tests


  • C reactive protein
  • Cardiac troponin in dogs
  • Heart issues in cats: test ProBNP
  • Horses: serum amyloid A
  • Cat urine: false positive WBC and fat droplets
• Diabetes Mellitus


  • Low insulin
  • hyper/hypoglycemia
• Diabetes Insipidus


  • Low ADH (PU/PD)
  • Released by pituitary gland for plasma protein
• Pancreatic exocrine functions


  • Digestive enzymes
  • Lipase: fat
  • Amylase: starches
  • Trypsin: proteins
• Pancreatic endocrine functions


  • Produce hormones (insulin)
• Amylase


  • Intestines, ovaries, testes, salivary glands (pigs)
  • Calcium dependent
  • Breaks down starches
  • Bound to globulins: dogs
  • Filtered by renal tubules, inc. could be kidney failure
  • Liver Kupffer cells (macrophages) reabsorb amylase in blood stream
  • Inc. hyperamylasemia: acute pancreatitis, renal disease, decreased GFR, intestinal disease, obstruction
  • falsely elevated with lipemia, hemolyzed, icteric samples
  • Decr. hypoamylasemia
  • False: occurs with elevated glucose and ascorbic acid
• Lipase


  • Pancreas, liver, small intestines
  • Pancreatic and lipoprotein lipase
  • Breaks down triglycerides
  • Filtered by renal tubules
  • Inc. hyperlipasemia: acute pancreatitis, hepatic disease, intestinal disease, corticosteroids/stress response
• Trypsin like immunoreactivity (TLI)


  • Different tests for species
  • 12 hour fast
  • Must be collected in red top tube or white top tube: no anticoags, no SST
  • Freeze if testing delayed by 1+ weeks
  • Lipemia can falsely decrease values
• Endocrine tests


  • Glucose
  • Protein metabolism
  • Lipid production
  • Cortisol
  • ACTH