Clinical ChemistryClinical ChemistryClinical Pathology, K. Canga, RVT

Reading and AssignmentReading and AssignmentLaboratory Procedures for

Veterinary Technicians,pp: 75 – 113

Study Guide as desired

Sample Collection & Sample Collection & HandlingHandling

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 samplesMost adverse affects on sample quality can

be avoided by careful sample ___________________ and ________________.

Sample Collection & Sample Collection & HandlingHandlingSpecific 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, ______________ (owner’s and patient’s), and patient’s ______number.

Serum Sample CollectionSerum Sample CollectionBlood should be collected from __________, fasted

animal when possibleAvoid ________________ 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.

Factors Influencing Factors Influencing ResultsResults

_______________: 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.

HemolysisHemolysisFluid 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.

Factors Influencing Factors Influencing ResultsResults

_________________ 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.

Factors Influencing Factors Influencing ResultsResults

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.

Reference RangesReference RangesReference 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.

Protein AssaysProtein AssaysPlasma 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

Protein AssaysProtein Assays

Total Plasma ProteinTotal Serum ProteinAlbuminGlobulinsAlbumin/Globulin RatioFibrinogen

Protein AssaysProtein AssaysTotal _____________ 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 ____________________.

Determination of Total Protein Levels: Determination of Total Protein Levels: Refractometric & Biuret Photometric Refractometric & Biuret Photometric MethodsMethodsRefractometric 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 _______________

AlbuminAlbuminAlbumin 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.

Globulins: Complex Group of 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.

Albumin/globulin (A/G) Albumin/globulin (A/G) ratioratio

Alteration in the normal ratio is frequently the first indication of a protein abnormality

Determined by dividing the albumin concentration by the globulin concentration.

FibrinogenFibrinogen3% to 6% of the total plasma

protein contentMost 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).

Hepatobiliary AssaysHepatobiliary AssaysLiver 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

Hepatobiliary AssaysHepatobiliary 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.

Hepatobiliary AssaysHepatobiliary AssaysLiver 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.

Enzymes Released from Enzymes Released from Damaged HepatocytesDamaged Hepatocytes

Alanine aminotransferase (ALT)Aspartate aminotransferase (AST)

Sorbitol dehydrogenaseGlutamate dehydrogenase

Alanine Aminotransferase Alanine Aminotransferase (ALT)(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 _______________.

ALT (cont’d)ALT (cont’d)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.

Aspartate Aminotransferase Aspartate Aminotransferase (AST)(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

AST (cont’d)AST (cont’d)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.

Sorbitol DehydrogenaseSorbitol DehydrogenaseFound in liver, kidney, small intestine,

skeletal muscle, and RBCsEspecially 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.

Glutamate dehydrogenaseGlutamate dehydrogenaseMitochondrial-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

Enzymes Associated with Enzymes Associated with CholestasisCholestasis

Alkaline phosphatase (AP)Gamma glutamyltransferase (GGT)

Alkaline Phosphatase (AP)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 ______________________________.

AP (cont’d)AP (cont’d)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.

AP (cont’d)AP (cont’d)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.

Gamma glutamyltransferase Gamma glutamyltransferase (GGT)(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.

Hepatocyte Function Hepatocyte Function TestsTests

BilirubinBile acids

CholesterolOthers (dye excretion, ammonia tolerance, caffeine clearance)

Hepatocyte Function TestsHepatocyte Function TestsEvaluated substances are taken up,

modified, produced, and/or secreted by the liver, primarily _____________ and __________ acids; other tests include albumin, ammonia, and cholesterol.

BilirubinBilirubinDerived 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

Bilirubin (cont’d)Bilirubin (cont’d)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.

Bile AcidsBile AcidsAid in ______ absorption and modulate

cholesterol levelsSynthesized 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.

Bile Acids (cont’d)Bile Acids (cont’d)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.

Bile Acids (cont’d)Bile Acids (cont’d)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.

CholesterolCholesterol

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

Cholesterol (cont’d)Cholesterol (cont’d)Assay is sometimes used as a screening test

for ________________________◦ _______________ hormone controls _________________

and _____________________ of cholesterol in the body

Other diseases associated with hypercholesterolemia include _____________________________, _______________ ____________, and nephrotic syndrome.

Administration of ____________________ may also cause an elevated blood cholesterol concentration.

Other Tests of Liver Other Tests of Liver FunctionFunction

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.

Kidney AssaysKidney AssaysKidney 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

Kidney AssaysKidney AssaysKidneys 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 __________.

Kidney Assays (cont’d)Kidney Assays (cont’d)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.

Kidney Assays (cont’d)Kidney Assays (cont’d)Primary serum chemistry tests for

kidney function: ____________________ and ______________.

Other tests are designed to evaluate the rate and efficiency of __________________ filtration.

Blood Urea Nitrogen Blood Urea Nitrogen (BUN)(BUN)

Also called serum urea nitrogenUrea is the principal end product of

__________________ breakdown in mammals.Urea passes through the glomerulus and enters

the renal tubulesApproximately __________ 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.

BUN (cont’d)BUN (cont’d)

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.

Serum Creatinine Serum Creatinine Formed from creatine found in ____________

muscle as part of muscle metabolismCreatine 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 animal’s total muscle mass.

Creatinine (cont’d)Creatinine (cont’d)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.

Creatinine (cont’d)Creatinine (cont’d)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 obstructionsUsed to evaluate __________________

function

BUN/Creatinine RatioBUN/Creatinine RatioBoth measurements have a wide range

of reference intervalsUsed in human medicine for diagnosis of

renal diseaseBUN and creatinine have an ___________

logarithmic relation.

Urine Protein/Creatinine Urine Protein/Creatinine Ratio 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.

Pancreas AssaysPancreas AssaysThe 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 ____________.

Pancreas AssaysPancreas 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.

Pancreas AssaysPancreas AssaysEndocrine Pancreas: interspersed within

the exocrine pancreatic tissue are the __________ of _________________

Four types of islet cells present; designated as α(_________), β(__________), δ(________), 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.

Pancreas AssaysPancreas AssaysDiseases 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

AmylaseAmylase

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.

Amylase (cont’d)Amylase (cont’d)

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.

LipaseLipaseNearly 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.

Trypsinlike Trypsinlike Immunoreactivity (TLI)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 specificTrypsin and trypsinogen are produced only in the

pancreasSerum TLI decreases in parallel with functional

pancreatic massDecreased _____________filtration rate increases

TLI Important to fast animal for ___ hours prior to

collecting sample.

Serum Pancreatic Lipase Serum Pancreatic Lipase Immunoreactivity (PLI)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.

Pancreas AssaysPancreas AssaysEndocrine Pancreas Tests

Primary test is blood __________; others include fructosamine, beta-hydroxybutyrate, glycosylated hemoglobin, serum cholesterol, and triglyceride

GlucoseGlucosePancreatic 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.

Glucose (cont’d)Glucose (cont’d)Ideally, samples should be taken from

an animal that has been fasted for ___ to ___ hours (ruminants should not be fasted)

____________ is preferredIt 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.

Glucose (cont’d)Glucose (cont’d)

_______________________ 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.

FructosamineFructosamineRepresents irreversible reaction of

glucose bound to protein, particularly _____________.

Increased fructosamine indicates persistent ____________________.

Glucose Tolerance TestGlucose Tolerance TestSometimes 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.

Glucose Tolerance Test Glucose Tolerance Test (cont’d)(cont’d)

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

Insulin Tolerance TestInsulin Tolerance TestProbes causes of diabetes

mellitusSerum glucose levels are

measured in blood samples obtained before __________ injection (fasting blood glucose) and every ___ minutes after injection for __ hours.

Other Endocrine Pancreas Other Endocrine Pancreas TestsTests

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.

Other Endocrine System Other Endocrine System AssaysAssaysAdrenocortical Function TestsThyroid AssaysPituitary Function Tests

Adrenocortical Function Adrenocortical Function TestsTests

Brain or pituitary ___________ leading to secondary bilateral adrenal ____________, idiopathic adrenal hyperplasia, or neoplasia may cause excessive ____________ release and _________________________. (Cushing’s disease)

Misuse of _________________________ is the most common cause of cortisol excess.

___________________________, (Addison’s disease) includes mineralocorticoid deficiency, which does not occur in iatrogenic disease from rapid withdrawal of _________________________.

Adrenocortical Function Tests Adrenocortical Function Tests (cont’d)(cont’d)

Addison’s 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.

Adrenocortical Function Tests Adrenocortical Function Tests (cont’d)(cont’d)

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 Addison’s disease, whereas normal (or increased) concentrations are expected in primary Addison’s disease.

Refer to pp 100-101 in your textbook for step-by-step instructions on performing ACTH stim. and Dex. suppression tests!

Thyroid AssaysThyroid AssaysBaseline 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.

Thyroid Assays (cont’d)Thyroid Assays (cont’d)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.

Pituitary Function TestsPituitary Function TestsDiagnosis of canine ______________

may be based on documentation of elevated ____________ hormone (GH).

Electrolyte AssaysElectrolyte AssaysElectrolytes: 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.

Electrolyte AssaysElectrolyte Assays___________, ______________,

____________, and ________________ are the four electrolytes in plasma.

Minerals of importance are __________, _____________, and ______________.

These two groups together are often simply called “________________”

Electrolyte AssaysElectrolyte Assays

CalciumInorganic PhosphorusSodiumPotassiumMagnesiumChlorideBicarbonate

CalciumCalciumDo not use _______, _________, or _________

anticoagulants to collect calcium samples for testing because they bind with calcium and make it unavailable for assay.

___% of the body’s 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)

Calcium (cont’d)Calcium (cont’d)______________________: 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.

Inorganic PhosphorusInorganic PhosphorusMost phosphorus in whole blood is found within

the RBCs as _______________ phosphorusPhosphorus 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.

Inorganic PhosphorusInorganic 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

SodiumSodium

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.

Sodium (cont’d)Sodium (cont’d)_______________________ 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.

PotassiumPotassiumMajor _______________ 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 body’s 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).

Potassium (cont’d)Potassium (cont’d)______________________: 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.

MagnesiumMagnesiumFunctions 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

ChlorideChloridePredominant ________________ 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

Chloride (cont’d)Chloride (cont’d)_______________________: may be

due to metabolic ___________ or renal tubular acidosis

_______________________: may be due to excessive ___________ , anorexia, ________________, or diabetes insipidus, or may accompany hypokalemia.

BicarbonateBicarbonateSecond 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.