Flashcards in Renal Ettinger Deck (408)
What is Carbamylated Hemoglobin?
(dissociated BUN that reacts with Hb) concentrations higher in dogs w/ renal disease (vs control) and higher w/ CRF vs ARF
What is GFR directly related to?
Functional renal mass
How is BUN made?
synthesis in liver via Ornithine cycle from catabolism of ammonia (from catabolism of endogenous and exogenous proteins)
Name 3 things that affect BUN.
Passive reabsorbed in tubules (greater extent when slow tubular flow (like with dehydration)
GI bleeding (increase nitrogenous compounds)
Drugs (increased catabolism with steroids, azathioprine), (decreased protein synthesis with tetracyclines)
How is creatinine made?
nonenzymatic breakdown product of phosphocreatinine in muscle, daily amount based on muscle mass
Which breed has higher creatinine?
Greyhounds (more muscle)
Describe the relationship btwn changes in BUN and creat.
Relationship of BUN or Crea concentration to GFR is a rectangular hyperbola; large changes in the early courses of renal disease cause only small increase in BUN/Crea vs small changes in GFR in advanced renal disease result in large changes
What does it imply when BUN and creatinine are increased?
Incr BUN & Crea implies that at least 75% of the nephrons are not functioning
What is cystatin C?
(small polypeptide protease inhibitor, freely filtered by glomeruli)
○ Filtered cystatin C - almost completely reabsorbed by proximal tubular cells and catabolized to AA
○ Produced at a constant rate = May serve as a marker of GFR
What can affect cystatin C?
inflammation or neoplasia
When does urinary concentrating ability lost?
When 66% of nephrons are lost
When does azotemia occur?
When 75% of nephrons are lost
When is it best to use the creatinine clearance?
When the patient is PU/PD but their BUN and creatinine are normal
Name agents that can be administered for a single injection to estimate GFR?
inulin, iohexol or Creatinine
When is dynamic renal scintigraphic methods with radioisotopes helpful?
When individual renal function information is needed
What is microalbuminuria an indication of ?
§ Humans: Early indication of vascular endothelial damage
Dogs/cats: 15-20% normal animals have an increase, unknown if results in progressive renal dz in vet med
What is the Bladder Tumor Antigen Test and what are problems with it?
latex agglutination dipstick test that detects glycoprotein antigen complex associated with bladder tumors in people
alse + occur w/ marked proteinuria, glucosuria, pyuria, hematuria
§ Good to differentiate neoplasia from normal dogs, but not good in animals with other LUT dz
What is the role of the water deprivation test?
tubular function test, used to decipher between DI vs psychogenic PD
When is the maximal stimulation of ADH release?
With 5% loss of BW!
What is the benefit of the gradual water deprivation test?
use to eliminate diagnostic confusion created by medullary wash out
○ Dogs with pyschogenic PD: Endogenous release of ADH, increased permeability of inner meduallary collecting ducts to urea and restoration of normal gradient of medulalary hypertonicity
Which electrolyte is good for pre renal vs renal disease?
Fractional excretion of Na: Pre-renal animals should have avid Na conservation!
What is the renal threshold for glucose in dogs and cats?
Renal threshold glucose – Cat 300, Dog 180 mg/dL
What ketones are noted on the dipstick?
○ Nitroprusside reagent (dipsticks) - Acetone < acetoacetate (NOT with beta-hydroxy)
What is the renal worm?
Which breed can get renal telangectasia?
What is a caudate cells?
transitional cells w/ tapered edges that originate from the renal pelvis
Which casts are normal in low number?
Occasional hyaline and granular casts
What is a hyaline cast?
pure proteins precipitates (Tamm-Horsfall mucoprotein and albumin), dissolve in dilute or alkaline urine; Small numbers can be seen with fever/exercise; seen in diseases assoc. with proteinuria
What is a coarsely or fine granular cast?
degeneration of cells in other casts or precipitation of filtered plasma proteins; * suggestive of ischemic or nephrotoxic renal tubular injury