Clinical%20Chemistry

1
Clinical Chemistry

• Clinical Pathology, K. Canga, RVT

2
Reading and Assignment

• Laboratory Procedures for Veterinary
  Technicians,pp 75 113
• Study Guide as desired

3
Sample Collection Handling

• Most chemical analyses require collection and
  preparation of _____________ samples
• Whole blood or blood plasma may be used for some
  test methods or with specific types of equipment
• Do not use __________ ___________ is usually the
  best choice for clinical chemistry samples
• Most adverse affects on sample quality can be
  avoided by careful sample ___________________ and
  ________________.

4
Sample Collection Handling

• Specific blood collection protocols vary
  depending on patient ______________, volume of
  blood needed, method of restraint, and type of
  sample needed
• Collect blood samples for chemical testing
  ______________ beginning treatment.
• __________________________ samples are preferred
  postprandial samples may produce inaccurate
  results.
• Label sample tube with _________ and time of
  collection, ______________ (owners and
  patients), and patients ______number.

5
Serum Sample Collection

• Blood should be collected from __________, fasted
  animal when possible
• Avoid ________________ by selecting needles of
  the correct size.
• Place blood in a tube that contains no
  _____________________. (Serum Separator tubes can
  also be used.)
• Allow blood to clot at room temperature for 20 to
  30 minutes. (If SST used, gently invert before
  clotting)
• Gently separate clot by _____________ with a
  wooden stick around the inside of the tube.
• Replace top and centrifuge at 2000 to 3000 rpm
  for 10 minutes.
• Remove ___________ with a pipette and transfer to
  appropriate container.

6
Factors Influencing Results

• _______________ may result when a blood sample
  is
• drawn into a moist syringe
• drawn in through too __________ of a needle
• drawn too _____________ in to needle
• mixed too __________________ after collection
• forced through a ___________ when being
  transferred to a tube
• _________________ as a whole blood sample
• Hemolysis can also occur when excess ____________
  is used to clean the skin and not allowed to dry
  prior to drawing blood.

7
Hemolysis

• Fluid from ________________ blood cells can
  dilute the sample, resulting in falsely
  ___________ concentrations of constituents
  present in the animal.
• Certain constituents, normally not found in high
  concentrations in serum or plasma, escape from
  ruptured blood cells, causing falsely elevated
  concentrations in the sample.
• Hemolysis may elevate levels of _____________,
  organic phosphorus, and certain ______________ in
  the blood
• Hemolysis also interferes with __________
  activity and ________________ determinations.

8
Factors Influencing Results

• _________________ contamination collection tubes
  must be chemically pure
• Improper ______________ label all tubes
  properly.
• _________________ influences obtain samples from
  a _____________animal
• Postprandial samples may have increased blood
  ______________ levels and decreased inorganic
  phosphorus.
• _______________ results in turbid or cloudy serum
• _________________ assays affected due to increase
  in GFR after eating.

9
Factors Influencing Results

• Improper Sample Handling complete chemical
  analysis within __________ of sample collection.
• Do not allow samples to become too _________.
• Thoroughly mix serum or plasma that has been
  frozen after thawing to avoid ____________________
  gradients.

10
Reference Ranges

• Reference ranges are a range of values derived
  when a __________________ has repeatedly assayed
  samples from a significant number of clinically
  _____________ animals of a given species using
  specific test methods.

11
Protein Assays

• Plasma proteins are produced primarily by the
  ___________ , as well as _________________________
  _ tissues, _______________ tissues, and
  ___________ cells
• Plasma proteins have many functions
• Form the structural matrix of all ________,
  ___________, and ______________
• Maintain _________________ pressure
• Serve as enzymes for biochemical reactions
• Act as ________________ in acid-base balance
• Serve as _______________
• Function in blood ___________________
• Defend the body against pathogenic microorganisms
• Serve as _____________/______________molecules
  for most constituents of plasma

12
Protein Assays

• Total Plasma Protein
• Total Serum Protein
• Albumin
• Globulins
• Albumin/Globulin Ratio
• Fibrinogen

13
Protein Assays

• Total _____________ protein measurements include
  fibrinogen values
• Total _____________ protein determinations
  measure all the protein fractions except
  fibrinogen.
• Total protein concentration may be affected by
  altered _____________ synthesis, altered protein
  _________________, and altered protein
  ______________ or excretion, as well as
  _________________ or ____________________.

14
Determination of Total Protein Levels
Refractometric Biuret Photometric Methods

• Refractometric method measures the refractive
  index of serum or plasma with a
  _____________________________.
• Refractive index of the sample is a function of
  the concentration of solid particles in the
  sample. In plasma, the primary solids are the
  _______________.
• Biuret method measures the number of molecules
  containing more than three peptide bonds in serum
  or plasma. (Done via ______________)
• Note Both techniques are _______________

15
Albumin

• Albumin comprises 35 to 50 of the total plasma
  _______________ in most animals.
• Significant _____________________________ is most
  likely caused by albumin loss.
• ___________ disease, ___________ disease, dietary
  intake, and intestinal protein _______________
  may influence the plasma albumin level.

16
Globulins Complex Group of ______________

• ____________ globulins are synthesized in the
  ___________ and primarily transport and bind
  proteins.
• __________ globulins include complement (C3
  C4), transferrin, and ferritin
• _______________ globulins (immunobulins) are
  synthesized by ___________ cells
• Concentration is calculated by determining
  difference between total protein and albumin
  concentrations.

17
Albumin/globulin (A/G) ratio

• Alteration in the normal ratio is frequently the
  first indication of a protein abnormality
• Determined by dividing the albumin concentration
  by the globulin concentration.

18
Fibrinogen

• 3 to 6 of the total plasma protein content
• Most common method of fibrinogen evaluation is
  the heat precipitation test (If you would like to
  know more about this, please reference chapter 2,
  pg 71).

19
Hepatobiliary Assays

• Liver functions include
• _________________ of amino acids, carbohydrates,
  and lipids
• _______________ of albumin, cholesterol, plasma
  protein, and clotting factors
• ___________________ and ________________ of
  nutrients related to bile formation
• secretion of ______________, or bile
• _________________, such as detoxification of
  toxins and ________________of certain drugs

20
Hepatobiliary Assays

• The __________________ is closely associated with
  the liver, both anatomically and functionally
  its primary function is as a storage site for
  _________.
• More than 100 different types of tests can be
  used to evaluate liver function
• Liver disease is usually greatly ________________
  before clinical signs appear.
• Damage to one _________ of the liver may not
  affect all liver functions.

21
Hepatobiliary Assays

• Liver function tests are designed to measure
  substances ________________ by the liver,
  modified by the liver, _________________ when
  _________________ are damaged, or those enzymes
  with altered serum concentrations as a result of
  _________________.
• Liver function tests are usually done with serial
  determinations and several different types of
  liver tests completed to assist in verifying
  functional status.

22
Enzymes Released from Damaged Hepatocytes

• Alanine aminotransferase (ALT)
• Aspartate aminotransferase (AST)
• Sorbitol dehydrogenase
• Glutamate dehydrogenase

23
Alanine Aminotransferase (ALT)

• Enzyme found free in the cytoplasm of hepatocytes
• Considered a ________-specific enzyme in dogs,
  cats, and primates
• ___________, ruminants, ________, and ___________
  do not have enough ALT in the hepatocytes for
  this enzyme to be considered liver specific
• Other sources of ALT are _________ cells,
  _____________ muscle, ____________ muscle, and
  the _______________.

24
ALT (contd)

• Used as a __________________ test for liver
  disease because it is not precise enough to
  identify specific liver diseases
• Increases are usually seen within _____ hours of
  hepatocyte damage and peak levels in 24 to 48
  hours
• Serum levels will return to reference ranges
  within a few weeks unless _____________ liver
  damage is present.

25
Aspartate Aminotransferase (AST)

• Found free in the cytoplasm of hepatocytes and
  bound to the __________________ membrane.
• Levels tend to rise more ___________ than ALT and
  return to normal levels within a day if chronic
  liver insult is not present
• Found in __________________ amounts in many other
  tissues, including _______, cardiac muscle,
  ____________ muscle, ______________, and pancreas

26
AST (contd)

• Increased blood level may indicate
  _______________ liver damage or be caused by
  strenuous exercise or intramuscular injection
• Assess _________ ____________ activity to rule
  out muscle damage before attributing an AST
  increase to liver damage.

27
Sorbitol Dehydrogenase

• Found in liver, kidney, small intestine, skeletal
  muscle, and RBCs
• Especially useful for evaluating liver damage in
  ___________ animals such as ________, ________,
  _________, ___________, and ____________.
• Plasma level rises __________ with
  ___________________ damage or ____________.
• Assays can be used in all species to detect
  hepatocellular damage or necrosis
• Tests not readily available to average vet. lab.

28
Glutamate dehydrogenase

• Mitochondrial-bound enzyme found in high
  concentrations in the hepatocytes of cattle,
  sheep, and goats
• No standardized test method has been developed
  for use in a veterinary practice laboratory

29
Enzymes Associated with Cholestasis

• Alkaline phosphatase (AP)
• Gamma glutamyltransferase (GGT)

30
Alkaline Phosphatase (AP)

• Present as isoenzymes in _________________ in
  bone, and as ___________________ in cartilage,
  intestine, placenta, and cells of the
  hepatobilary system in the liver.
• Isoenzymes of AP remain in circulation for
  approximately 2 to 3 days, with the exception of
  intestinal isoenzyme, which circulates for just a
  few hours.
• A corticosteroid isoenzyme of AP has been
  identified in dogs with exposure to increased
  endogenous or exogenous __________________________
  ____.

31
AP (contd)

• Source of an isoenzyme or location of the damaged
  tissue is determined by electrophoresis and other
  tests performed in commercial or research
  laboratories.
• In older animals, nearly all circulating AP comes
  from the ___________ as _________ development
  stabilizes.

32
AP (contd)

• Assay in a practice laboratory determines the
  total blood concentration.
• Concentrations used to detect _________________
  in adult dogs and cats
• Not a useful test for detecting cholestasis in
  cattle and sheep because of wide fluctuations in
  ____________blood levels in these species.

33
Gamma glutamyltransferase (GGT)

• Also called gamma glutamyltranspeptidase
• Primary source is ____________
• Also found in _________ , _____________, and
  _____________,epithelia, as well as in the
  kidneys, pancreas, intestine, and muscle cells
• Cattle, horses, sheep, goats, and birds have
  ___________blood activity than dogs and cats
• Blood level is evaluated with liver disease,
  especially _________________disease.

34
Hepatocyte Function Tests

• Bilirubin
• Bile acids
• Cholesterol
• Others (dye excretion, ammonia tolerance,
  caffeine clearance)

35
Hepatocyte Function Tests

• Evaluated substances are taken up, modified,
  produced, and/or secreted by the liver, primarily
  _____________ and __________ acids other tests
  include albumin, ammonia, and cholesterol.

36
Bilirubin

• Derived from the breakdown of ___________________
  by macrophages in the _____________
• Measurements of the circulating levels of these
  various populations of bilirubin can help
  pinpoint the cause of _______________.
• Assays can directly measure _________ bilirubin
  (____________ bilirubin plus ________________
  bilirubin), and _______________ bilirubin

37
Bilirubin (contd)

• Blood levels of _______________ bilirubin are
  elevated with _________________ damage or bile
  duct injury/obstruction
• Blood levels of ___________________ bilirubin are
  elevated with excessive erythrocyte
  __________________ or defects in the transport
  mechanism that allow bilirubin to enter
  hepatocytes for conjugation.

38
Bile Acids

• Aid in ______ absorption and modulate cholesterol
  levels
• Synthesized by hepatocytes from cholesterol and
  conjugated with glycine or taurine
• Conjugated bile acids are secreted across the
  _______________ membrane and reach the duodenum
  by the biliary system
• Gallbladder stores ________ acids (except in the
  ___________) until contraction associated with
  feeding.

39
Bile Acids (contd)

• Any process that impairs the hepatocellular,
  biliary, or portal enterohepatic circulation of
  bile acids results in elevated serum levels.
• Serum level is normally ______________ after a
  meal because the gallbladder has contracted and
  released increased amounts of _______ into the
  __________________.
• Paired serum samples performed after 12 hours of
  fasting and 2 hours postprandial are needed to
  perform the test.
• Difference in concentration of the samples is
  reported
• Only a single sample is tested in horses.

40
Bile Acids (contd)

• Inadequate ______________ or spontaneous
  ___________________ contraction can increase
  fasting bile acids prolonged fasting and
  _______________ decreases bile acids
• Most commonly used method for determination of
  bile acids is an enzymatic method measured by
  machine
• Bile acid test that uses immunologic methods
  (ELISA) is available for use in the veterinary
  clinic.

41
Cholesterol

• Produced primarily in the __________ and ingested
  in food.
• _________________ causes an increase in serum
  cholesterol in some species
• Some automated analyzers provide cholesterol and
  other lipoprotein values
• Fluoride and oxalate anticoagulants may
  ______________ enzymatic method results

42
Cholesterol (contd)

• Assay is sometimes used as a screening test for
  ________________________
• _______________ hormone controls
  _________________ and _____________________ of
  cholesterol in the body
• Other diseases associated with hypercholesterolemi
  a include _____________________________,
  _______________ ____________, and nephrotic
  syndrome.
• Administration of ____________________ may also
  cause an elevated blood cholesterol concentration.

43
Other Tests of Liver Function

• Dye excretion bromsulfophthalein excretion and
  indocyanine green excretion tests require
  administration of a dye that binds to a protein
  in serum.
• Ammonia tolerance any condition that reduces the
  uptake of ammonia or conversion of ammonia to
  urea can lead to increased plasma ammonia
  concentration.
• Caffeine clearance test used in human medicine
  few experimental studies have been performed in
  canine species.

44
Kidney Assays

• Kidney functions
• _______________ or ____________water and
  electrolytes in times of imbalance.
• Excrete or conserve _________ ions to maintain
  blood _______ within normal limits.
• Conserve ________________
• Remove end products of ______________ metabolism
• Produce renin, _______, and prostaglandins
• Lower blood pressure
• Regulate acid secretion in the stomach
• Aid in regulation of body temperature and
  platelet aggregation
• Aid in vitamin D activation

45
Kidney Assays

• Kidneys receive blood from the _________
  arteries blood enters the ________________ of
  the ______________where nearly all water and
  small dissolved solutes pass into the collecting
  tubules.
• Each nephron contains sections that function to
  ______________ or ____________specific solutes.
• Resorption of glucose occurs in the _______
• Secretion and reabsorption of mineral salts
  occurs in the ascending limb of the loop of
  __________ and in the __________.

46
Kidney Assays (contd)

• Nephron has a specific reabsorptive capability
  for each substance called the ____________________
  _____.
• Blood returns from the _____________ to the rest
  of the body through the renal __________, which
  connect to the caudal ___________ ___________.
• _____________ and ___________ may be analyzed to
  evaluate kidney function.

47
Kidney Assays (contd)

• Primary serum chemistry tests for kidney
  function ____________________ and
  ______________.
• Other tests are designed to evaluate the rate and
  efficiency of __________________ filtration.

48
Blood Urea Nitrogen (BUN)

• Also called serum urea nitrogen
• Urea is the principal end product of
  __________________ breakdown in mammals.
• Urea passes through the glomerulus and enters the
  renal tubules
• Approximately __________ the urea is reabsorbed
  in the tubules and the remainder excreted in the
  urine
• If the kidneys do not remove sufficient urea from
  the plasma, BUN levels _________________.
• Contamination of the blood sample with
  urease-producing bacteria may result in
  decomposition of urea and decreased BUN levels.
• Staphylococcus aureus, Proteus spp. and
  Klebsiella spp.

49
BUN (contd)

• Several photometric tests are available to
  measure urea nitrogen
• _________________ results in increased retention
  of urea in the blood (_______________)
• High-______________ diets and strenuous exercise
  may cause elevated BUN levels because of
  increased _____________________ breakdown.

50
Serum Creatinine

• Formed from creatine found in ____________ muscle
  as part of muscle metabolism
• Creatine diffuses out of muscle cells and into
  most body fluids, including ___________
• Amount of creatine metabolized to creatinine
  usually remains _______________, as does blood
  level of creatinine
• Total amount of ______________ is a function of
  the animals total muscle mass.

51
Creatinine (contd)

• Serum creatinine is filtered through the
  _______________ and eliminated in urine
• Any condition that ___________ glomerular
  filtration rate alters serum ____________ level
• Nearly ____ of kidney tissue must be
  _________________ before blood creatinine levels
  rise.
• __________________ decreases in creatinine occur
  from transient increase in glomerular filtration
  rate after a meal.

52
Creatinine (contd)

• Increased serum creatinine levels are seen when
  there is a lack of functional _______________
• Serum creatinine concentrations are influenced
  by
• Fluid and _______________ levels
• _____________ factors, such as shock
• _________________ factors, such as bladder and
  urethral obstructions
• Used to evaluate __________________ function

53
BUN/Creatinine Ratio

• Both measurements have a wide range of reference
  intervals
• Used in human medicine for diagnosis of renal
  disease
• BUN and creatinine have an ___________
  logarithmic relation.

54
Urine Protein/Creatinine Ratio

• Mathematical method that compares urine
  ______________ level with urine
  _____________________ levels in a single urine
  sample
• 5 to 10 mL of urine collected via
  ________________________.
• Sample is centrifuged and ____________________
  used to determine both concentrations for each
  sample by photometric methods.

55
Pancreas Assays

• The pancreas has both ______________ and
  _________________ functions.
• Pancreatic endocrine function involves production
  of ____________ and ___________. Diabetes
  mellitus, or a deficiency of ___________
  resulting in hyperglycemia, is the most common
  endocrine disorder of the pancreas.
• Pancreatic exocrine function involves the
  production of ____________, _____________, and
  ____________. Most pancreatic disturbances occur
  in the exocrine function of the pancreas.
  ___________ seem to have a greater incidence than
  ____________.

56
Pancreas Assays

• Exocrine pancreas also referred to as the acinar
  pancreas.
• Secretes enzymes necessary for ____________ into
  the small intestine
• Primary pancreatic enzymes are trypsin, amylase,
  and lipase
• Trauma to pancreatic tissue is often associated
  with pancreatic duct ____________________ that
  results in a back-up of digestive enzymes into
  peripheral circulation.

57
Pancreas Assays

• Endocrine Pancreas interspersed within the
  exocrine pancreatic tissue are the __________ of
  _________________
• Four types of islet cells present designated as
  a(_________), ß(__________), d(________), and
  ____ cells.
• Delta and PP cells comprise less than 1 of the
  islet cells and secrete somatostatin and
  pancreatic polypeptide, respectively.
• Beta cells comprise approximately _____ of the
  islet cells and secrete _____________.
• 20 consists of alpha cells that secrete glucagon
  and somatostatin.

58
Pancreas Assays

• Diseases of the pancreas may result in
  inflammation and cellular damage that causes
  leakage of ______________ enzymes or insufficient
  ___________________ or ___________________of
  enzymes.
• Primary ______________ pancreas tests are amylase
  and lipase trypsinlike immunoreactivity and
  pancreatic lipase immunoreactivity

59
Amylase

• Primary source is the pancreas, but also produced
  in the ______________ glands and small intestine.
• Increases in serum amylase are nearly always
  caused by pancreatic disease (_________________),
  especially when accompanied by increased lipase
  levels
• ______________, intestinal obstruction, or
  intestinal ___________________may also result in
  increased serum amylase from increased absorption
  of intestinal amylase into bloodstream.

60
Amylase (contd)

• Animals have a greater serum amylase activity
  level than humans (___ times greater in dog and
  cat) so it is recommended to dilute the serum
  with normal saline before testing if using tests
  designed for human samples.
• ______________, ________________, and calcium
  cheleating anticoagulants will affect results.

61
Lipase

• Nearly all serum lipase is derived from the
  ____________________.
• Excess lipase is normally filtered through the
  ________________, so lipase levels tend to remain
  normal in the early stages of pancreatic disease.
• Increased lipase is also seen in ___________
  failure, hyperadrenocorticism, dexamethasone
  treatment, and bile tract disease.
• Manual methods for testing are cumbersome, easier
  to use automated or SNAP test.

62
Trypsinlike Immunoreactivity (TLI)

• Considered the test of choice, TLI is highly
  specific and sensitive in detecting
  __________________ insufficiency in dogs.
• Radioimmunoassay using antibodies to trypsin that
  can detect both trypsinogen and trypsin
• Antibodies are species specific
• Trypsin and trypsinogen are produced only in the
  pancreas
• Serum TLI decreases in parallel with functional
  pancreatic mass
• Decreased _____________filtration rate increases
  TLI
• Important to fast animal for ___ hours prior to
  collecting sample.

63
Serum Pancreatic Lipase Immunoreactivity (PLI)

• Serum feline PLI is specific for
  ___________________ and is recommended instead of
  the previously validated serum feline TLI to
  diagnose cats with symptoms of pancreatitis.
• Cats must also be fasted for ___ hours prior to
  drawing blood sample.

64
Pancreas Assays

• Endocrine Pancreas Tests
• Primary test is blood __________ others
  include fructosamine, beta-hydroxybutyrate,
  glycosylated hemoglobin, serum cholesterol, and
  triglyceride

65
Glucose

• Pancreatic islets respond directly to blood
  glucose concentrations and release ____________
  (from the beta cells) or ______________ (from the
  alpha cells) as needed.
• Blood glucose level is used as an indicator of
  _____________________ metabolism in the body and
  as a measure of _________________ function of the
  ________________.
• Some tests for blood glucose react with only
  glucose, whereas others may quantify all sugars
  in the blood.

66
Glucose (contd)

• Ideally, samples should be taken from an animal
  that has been fasted for ___ to ___ hours
  (ruminants should not be fasted)
• ____________ is preferred
• It is essential to centrifuge sample and transfer
  serum to another tube immediately because blood
  continues to use glucose at a rate of 7 to 10
  per hour if allowed to remain in contact with the
  serum or plasma.

67
Glucose (contd)

• _______________________ may result from
  ______________ ____________, or any of several
  nonpancreatic causes such as stress and
  hyperadrenocorticism (_____________ disease)
• Diagnosis of diabetes mellitus is not made
  unless _________________ accompanies
  hyperglycemia.
• _______________________ may result from
  malabsorption, severe liver disease, or prolonged
  contact of the _________ or _________ with the
  cellular component of blood.

68
Fructosamine

• Represents irreversible reaction of glucose bound
  to protein, particularly _____________.
• Increased fructosamine indicates persistent
  ____________________.

69
Glucose Tolerance Test

• Sometimes referred to as glucose curve
• Challenge the pancreas with a glucose load and
  measure ___________ effect by blood or urine
  glucose concentrations used to rule out
  __________ ____________.
• IV test is preferred over oral because oral test
  is affected by abnormal intestinal function such
  as ______________ or hypermotility, and
  excitement.

70
Glucose Tolerance Test (contd)

• Glucose is injected after a 12- to 16-hour fast
  (except in ruminants)
• Blood glucose is subsequently checked and
  progress mapped as a tolerance curve.
• Results are standardized as disappearance
  half-lives or glucose turnover rates expressed as
  percent/minute

71
Insulin Tolerance Test

• Probes causes of diabetes mellitus
• Serum glucose levels are measured in blood
  samples obtained before __________ injection
  (fasting blood glucose) and every ___ minutes
  after injection for __ hours.

72
Other Endocrine Pancreas Tests

• Glucagon tolerance indicated when repeated
  borderline results are obtained.
• Insulin/glucose ratio involves simultaneous
  measurements in a fasting animal.
• Miscellaneous tests of insulin release glucose,
  epinephrine, leucine, tolbutamide, or calcium
  challenges may be attempted.

73
Other Endocrine System Assays

• Adrenocortical Function Tests
• Thyroid Assays
• Pituitary Function Tests

74
Adrenocortical Function Tests

• Brain or pituitary ___________ leading to
  secondary bilateral adrenal ____________,
  idiopathic adrenal hyperplasia, or neoplasia may
  cause excessive ____________ release and
  _________________________. (Cushings disease)
• Misuse of _________________________ is the most
  common cause of cortisol excess.
• ___________________________, (Addisons disease)
  includes mineralocorticoid deficiency, which does
  not occur in iatrogenic disease from rapid
  withdrawal of _________________________.

75
Adrenocortical Function Tests (contd)

• Addisons disease also may result from Lysodren
  (Rx for adrenal hyperplasia) or from
  ____________________ causes.
• Dogs with nonadrenal disease such as diabetes
  mellitus, liver disease, or renal disease may
  have false-positive results
• _________________________ hormone (ACTH) and
  _____________ concentrations may be a helpful
  diagnostic aid in differentiating primary
  (adrenal-dependent) from secondary
  (pituitary-dependent) hypoadrenocorticism.

76
Adrenocortical Function Tests (contd)

• Measurements taken as _____________ data and
  compared with data obtained from challenge to the
  adrenal gland with ACTH or dexamethasone.
• Low to undetectable ACTH concentrations occur in
  secondary Addisons disease, whereas normal (or
  increased) concentrations are expected in primary
  Addisons disease.
• Refer to pp 100-101 in your textbook for
  step-by-step instructions on performing ACTH
  stim. and Dex. suppression tests!

77
Thyroid Assays

• Baseline thyroxine (T4) concentrations are used
  diagnostically, but normal values vary
  dramatically
• Semiquantitative immunologic tests are available
  to measure T4 concentrations
• ________ response test is used on small animals
  (except _________________ cats) and horses and
  provides a reliable diagnostic separation of
  patients with normal versus abnormal thyroid
  function.

78
Thyroid Assays (contd)

• Free T4 test measures the fraction of thyroxine
  not bound to protein levels are less influenced
  by nonthyroidal diseases or drugs than are total
  T4 concentrations.
• Triiodothyronine (T3) suppression test based on
  the expected ____________________ regulation of
  TSH induced by high concentrations of
  circulating thyroid hormone.

79
Pituitary Function Tests

• Diagnosis of canine ______________ may be based
  on documentation of elevated ____________ hormone
  (GH).

80
Electrolyte Assays

• Electrolytes negative ions, or ___________, and
  positive ions, or ___________, of elements found
  in all body fluids of all organisms.
• Functions of electrolytes include
• maintenance of ________ balance,
• fluid ____________ pressure, and
• normal ___________ and ____________ functions.
• Also function in the maintenance and activation
  of several enzyme systems and in acid-base
  regulation
• Acid-base status depends on _________________ and
  should be interpreted together.

81
Electrolyte Assays

• ___________, ______________, ____________, and
  ________________ are the four electrolytes in
  plasma.
• Minerals of importance are __________,
  _____________, and ______________.
• These two groups together are often simply called
  ________________

82
Electrolyte Assays

• Calcium
• Inorganic Phosphorus
• Sodium
• Potassium
• Magnesium
• Chloride
• Bicarbonate

83
Calcium

• Do not use _______, _________, or _________
  anticoagulants to collect calcium samples for
  testing because they bind with calcium and make
  it unavailable for assay.
• ___ of the bodys calcium is in _________.
• Remaining calcium maintains __________________
  excitability and tone, acts as an enzyme
  activator, plays a role in _____________ , and
  helps in transport of ions across cell membranes.
• Serum calcium levels vary with serum protein and
  albumin levels (these levels should be
  _____________ with increased serum calcium)

84
Calcium (contd)

• ______________________ seen with
  hyperparathyroidism, excessive vitamin __ intake,
  bony ______________.
• ______________________ seen in malabsorption,
  ____________, pancreatic necrosis,
  hypoalbuminemia, hypoparathyroidism,
  gastrointestinal __________ or blockage in
  ruminants, postparturient ________________ in
  cow, bitch, ewe, and mare.

85
Inorganic Phosphorus

• Most phosphorus in whole blood is found within
  the RBCs as _______________ phosphorus
• Phosphorus in plasma and serum is _____________
  phosphorus and is the phosphorus assayed in the
  laboratory
• Plasma or serum phosphorus and calcium
  concentrations are _____________ related as
  phosphorus concentrations decrease, calcium
  concentrations ___________.
• ___________________ samples should not be used
  because organic phosphorus liberated from
  ______________ may be hydrolyzed to inorganic
  phosphorus, which results in a falsely ______
  inorganic phosphorus concentration.

86
Inorganic Phosphorus

• ______________________________ may be seen in
  renal failure, ________, excessive vitamin __
  intake, ethylene glycol poisoning, and
  hypoparathyroidism.
• ______________________________ may occur in
  primary hyperparathyroidism, ____________________,
  inadequate intake, hyperinsulinism,
  _____________________, lymphosarcoma,
  hyperadrenocorticism

87
Sodium

• Most abundant ______________ cation that plays a
  major role in the distribution of ___________ and
  the maintenance of _____________ pressure of
  fluids in the body.
• If ________ is retained, _____ is retained.
• Sodium heparin should not be used as an
  anticoagulant because it may falsely _____
  results.

88
Sodium (contd)

• _______________________ is rare unless the animal
  is deprived of ________.
• _______________________ is quite common and is
  seen in such conditions as ________ failure,
  __________, or diarrhea use of diuretics
  excessive ____ congestive heart failure water
  toxicity or excessive ________ administration.

89
Potassium

• Major _______________ cation important for
  normal _______________ function, nerve impulse
  transmission, and ________________ metabolism.
• __________ levels are so ____ that measurement of
  serum potassium does not give much information
  about the bodys potassium levels.
• ___________ is the preferred sample because
  platelets may release potassium during the
  clotting process (elevating K levels).
• ______________ releases potassium into plasma
  (elevating K levels).

90
Potassium (contd)

• ______________________ will be seen in adrenal
  cortical hypofunction, ____________, or
  late-stage ________ failure.
• ______________________ will be seen in
  ____________, ____________ therapy, or excess
  fluid _________ due to diuretics, vomiting, and
  diarrhea.

91
Magnesium

• Functions to activate _____________ systems and
  involved in production and decomposition of
  acetylcholine
• __________ and ________ are the only domestic
  animals that show clinical signs related to
  magnesium deficiencies.
• Imbalance in __________ -_____________ ratio can
  lead to muscle _________ in cattle and sheep
• Anticoagulants other than ___________ may
  artificially decrease results
• ________________ may elevate the results through
  liberation of magnesium from RBCs

92
Chloride

• Predominant ________________ ion.
• Functions in maintenance of _______ distribution,
  ____________ pressure, and the normal
  ________/_________ ratio.
• Concentration is regulated by the ___________.
• There is a close relationship between ________
  and ___________ levels
• ______________ may affect test results by
  diluting the sample with RBC fluid

93
Chloride (contd)

• _______________________ may be due to metabolic
  ___________ or renal tubular acidosis
• _______________________ may be due to excessive
  ___________ , anorexia, ________________, or
  diabetes insipidus, or may accompany hypokalemia.

94
Bicarbonate

• Second most common __________ of plasma.
• Functions in the bicarbonate/carbonic acid
  __________ system and aids in the transport of
  ____ from the tissues to the lungs.
• Kidney regulates bicarbonate levels in the body
  by excreting excesses after it has ____________
  all that it needed.
• Levels are frequently estimated from blood carbon
  dioxide levels (___________ blood best)
• Bicarbonate level is approximately ___ of the
  total carbon dioxide measured.