The
urine Indican test is also called an Obermeyer test,
which is an indicator of intestinal toxemia and overgrowth of anaerobic
bacteria. Indican is an indole produced
when bacteria in the intestine act on the amino acid, tryptophan. Most indoles are excreted
in the feces. The remainder is absorbed, metabolized by the liver, and excreted
as indican in the urine.
Normally, only a small amount of indican is found in
the urine. The amount of urine indican increases with high protein diets or
inefficient protein digestion. If protein is not digested adequately, bacteria
act on the protein causing putrefaction in the colon and the production of indoles, which are absorbed and converted in the liver to
Indican. Conditions that lead to excess
urine Indican include:
§ Maldigestion and/or
malabsorption of protein
o
Hypochlorhydria
(insufficient stomach acid; use of antacids or H2 blockers)
o
Stomach
cancer
o
Insufficient
digestive enzymes (proteases such as trypsin, pepsin,
chymotrypsin)
o
Malabsorption
syndromes (sprue, Hartnup
disease, a rare disorder in which amino acids are poorly absorbed from the
intestine, etc.)
§ Bacterial overgrowth
in the small and/or large intestine
o
intestinal
obstruction
o
concurrent
intestinal parasitic infections
o
concurrent
intestinal fungal infection
§ Liver Dysfunction?
The inability to digest protein can have
adverse affects on glycemic control, hormone balance and water balance.
(Obermeyer test - Indoxyl
Sulfate)
Following absorption, indole
is converted to 3-hydroxy indole (indoxyl potassium
sulfate and indoxyl glucuronate), which are termed indicans,
in the liver.
Indole (oxidized) ® indoxyl + H2O2 ® indoxyl sulfuric acid K + indoxyl potassium sulfate (indican)
Specimen requirements: No special patient
preparation required. If the assay is not run
immediately, place sample in labeled plastic tube and freeze.
Detection of indican in the urine depends upon its
decomposition and subsequent oxidation of indoxyl to indigo blue and its
absorption into a chloroform layer. The resulting
color is visually compared to a color chart and graded as follows:
|
Your
Result
|
Negative
(Normal)
|
= Clear
or blue tinge
|
|
|
1+ (Slightly Positive)
|
= Slight
blue, yellow, mint green
|
|
|
2+ (Positive)
|
= Dark
blue, light green, golden brown
|
|
|
3+ (High Positive)
|
= Violet,
indigo, dark brown
|
|
|
4+ (Very High Positive)
|
= Jet
black
|
References
include
§ Todd J: Clinical
Diagnosis and Management by Laboratory Methods. WB Saunders, Phil, Pa
1979. pp 592-3
§ Greenberger N, Saegh S, and Ruppert R: Urine
indican excretion in malabsorption disorders. Gastroenterol
55:204-11, 1968
§ Curzon G and Walsh J:
Value of measuring urinary indicant excretion. Gut 7:711, 1966
§ Asatoor A, London D, Craske J, and Milne M: Indole production in Hartnup's
disease. Lancet i:126-8, 1963.
