Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

CLSF
8218
CLU
8531
FCCK
90162
Chloride, Spinal Fluid
Clinical Information: Cerebrospinal fluid, which cushions the brain and spinal cord, is formed by
both ultrafiltration and active secretion from plasma.
Useful For: This test is of limited clinical utility.
Interpretation: Cerebrospinal fluid chloride levels generally reflect systemic (blood) chloride levels.
Reference Values:
120-130 mmol/L
Chloride, Urine
Clinical Information: Chloride is the major extracellular anion. Its precise function in the body is
not well understood; however, it is involved in maintaining osmotic pressure, proper body hydration,
and electric neutrality. In the absence of acid-base disturbances, chloride concentrations in plasma will
generally follow those of sodium (Na+). Since urine is the primary mode of elimination of ingested
chloride, urinary chloride excretion during steady state conditions will reflect ingested chloride, which
predominantly is in the form of sodium chloride (NaCl). However, under certain clinical conditions, the
renal excretion of chloride may not reflect intake. For instance, during states of extracellular volume
depletion, urine chloride (and sodium) excretion is reduced.
Useful For: As an indicator of fluid balance and acid-base homeostasis
Interpretation: Urine sodium and chloride excretion are similar and, under steady state conditions,
both the urinary sodium and chloride excretion reflect the intake of NaCl. During states of extracellular
volume depletion, low values indicate appropriate renal reabsorption of these ions, whereas elevated
values indicate inappropriate excretion (renal wasting). Urinary sodium and chloride excretion may be
dissociated during metabolic alkalosis with volume depletion where urine sodium excretion may be
high (due to renal excretion of NaHCO3) while urine chloride excretion remains appropriately low.
Reference Values:
40-224 mmol/24 hours
Clinical References: 1. Tietz Textbook of Clinical Chemistry. Third edition. Edited by CA Burtis,
ER Ashwood. Philadelphia, WB Saunders Co, 1999 2. Toffaletti J: Electrolytes. In Professional Practice
in Clinical Chemistry: A Review. Edited by DR Dufour, N Rifai. Washington, AACC Press, 1993 3.
Kamel KS, Ethier JH, Richardson RM, et al: Am J Nephrol 1990;10:89-102 4. Package insert: Roche
reagent. Indianapolis, IN 46256, 8/99
Cholecystokinin (CCK)
Clinical Information: Cholecystokinin is a 33 amino acid peptide having a very similar structure to
Gastrin. Cholecystokinin is present in several different sized forms including a 58 peptide Pro-CCK and
22, 12, and 8 peptide metabolites. The octapeptide retains full activity of the 33 peptide molecule.
Cholecystokinin has an important hysiological role in the regulation of pancreatic secretion, gallbladder
contraction and intestinal motility. Cholecystokinin levels are elevated by dietary fat especially in
diabetics. Elevated levels are seen in hepatic cirrhosis patients. Cholecystokinin is found in high levels
in the gut, in the brain and throughout the central nervous system.
Reference Values:
Up to 80 pg/mL
This test was developed and its performance characteristics
determined by Inter Science Institute. It has not been cleared or
approved by the US Food and Drug Administration. The FDA has
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