INDICAN — the general name of some derivatives of indoxyl (beta oxyindole) which are formed in animal and vegetable organisms; the maintenance of an indican serves auxiliary in blood serum and urine a wedge. - biochemical, the test at a number of diseases.
Distinguish the so-called «animal» indican found in blood and urine of animals and the person who represents potassium or sodium salt indoksilserny or indoksilglyukuronovy to - you (see. Indole ), and the «vegetable» indican which is found in indigonosny plants (the mountaineer tinctorial, an oleander tinctorial, etc.) and being glucoside of indoxyl. Vegetable And. it is used as an initial product for receiving indigotin.
Structure And. it was established by A. Bayer in 1905. «Animal» And. represents the colourless crystals differing in bitter taste easily water soluble. All types And. at acid or enzymic hydrolysis give indoxyl:
«Animal» And. it is formed in a liver of the person and animals in the course of neutralization of the indoxyl arriving with blood of a portal vein and being waste product of intestinal microflora. The hydroxylic group of indoxyl is etherified sulfuric or glucuronic to - that. Formed in a liver And. comes to blood and it is removed with urine. Normal blood serum contains 0,02 — 0,08 mg of % And., with urine in days at the healthy person from 5 to 20 mg
of I. Kolichestvo I. in blood serum are allocated it is increased at a renal failure, uraemia, disturbance of activity went. - kish. path. A hyperindicanemia (see. Indicanemia ) it is expressed at hron, uraemias it is brighter, than at acute uraemia, and can be followed by accumulation And. as well in cerebrospinal liquid. At dysfunction went. - kish. path contents And. raises not only in blood, but also in urine (see. Indicanuria ). Century of X. Vasilenko (1927) provides data that patients with dysfunction of kidneys have a concentration And. in urine surpasses concentration it in blood no more than by 13 times while at a hyperindicanemia of not renal origin this figure can increase to 70. L. V. Hankes et al. (1970) established that at a pellagra allocation And. with urine decreases, and later Voykulsky (V. Voiculscy, 1973) found that at an endogenous pellagra daily excretion And. raises; contents And. in urine increases also at Hartnup's disease (see. Hartnupa disease ). According to Flynn (J. N of Flinn) et al. (1964), contents And. in urine decreases at gout, a pseudorheumatism with psoriasis. Increase in quantity And. in urine at the person it is observed at locks, intestinal impassability, a typhoid, strengthening of processes of rotting in intestines. According to the Fisher (S. Ilea, 1962), at cancer went. - kish. path allocation And. with urine sharply increases. At purulent processes in a bladder or urinary tract under the influence of microorganisms there can be a splitting And. with formation of blue indigotin owing to what the emitted urine gets blue coloring.
Methods of definition
In urine contents And. determine by Kumon's method based on condensation And. with ninhydrin therefore the reaction product painted in red color which is extracted chloroform is formed and kolorimetrirut against standard solution I. (10 mg uric And. in 100 ml of a distilled water and 1 mg of sodium fluoride), stored long time. Add 0,5 ml of 2% of lead acetate to 10 ml of urine, stir up and filter. From a filtrate take 5,25 ml (that corresponds to 5 ml of urine), add 1 ml of 10% salt to - you and 3 — 4 drops of 3% of solution of ninhydrin and immerse for 3 min. in the boiling water bath. After cooling mix is poured in a separatory funnel, add 5 ml of chloroform, stirred up and in 3 min. merge the chloroform painted in red color. The same is made with test, in to-ruyu instead of urine add standard solution I.
In blood presence And. define by means of the qualitative test carrying the name of test of Rosenberg. Blood serum or blood are besieged the equal number of 20% trichloroacetic to - you then centrifuge; 1 ml of a tsentrifugat pour in a thin-walled test tube, on a wall carefully add a cut konts. salt to - that. In a few minutes on border of liquids the violet ring is formed. Positiveness of test is determined by the speed of emergence and intensity of coloring of this ring. Test is positive in all cases of a heavy renal failure.
For quantitative definition And. in blood blood serum is mixed with an equal capacity of 20% trichloroacetic to - you, filtered and to a filtrate add several drops of spirit solution of methyl-isopropyl phenol and Obermayer's reactant — 2 g of ferric chloride to 1 l konts. salt to - you with ud. weighing 1,19 (see. Obermayera test ). In 20 min. the formed krasnofioletovy pigment is taken by 2 ml of chloroform and kolorimetrirut (reaction of Yolles — Haas).
During the definition And. in urine to 2 — 3 ml of protein-free urine flow equal volume konts. salt to - you with ud. weighing 1,19, several drops of 2% of potassium permanganate and 10 — 15 drops of chloroform. Contents of a test tube are carefully mixed. At presence And. chloroform is painted in blue color. Intensity of coloring is proportional to amount of the formed blue indigotin. It is necessary to consider that excess of potassium permanganate oxidizes blue indigotin in the isatin having yellow color. Modification of this qualitative test on presence And. in urine so-called reaction of Jaffe is: add 1,5 ml of lead acetate to 15 ml of urine (10% solution), filter, add equal volume to a filtrate konts. salt to - you, 2 — 3 drops of 5% of Calcium chloratum and 2 — 3 ml of chloroform, carefully mix. If urine is normal, the water layer is painted in green-blue color, and chloroformic — in blue.
When investigated accepted the medicinal substances containing iodine, the chlorouniform extract of urine is painted in pink or red color, sometimes with a violet shade. Red coloring disappears after addition of a small amount of hyposulphite.
See also Altshuler method .
Bibliography: Karrer P. A course of organic chemistry, the lane with it., page 693, etc., L., I960; Maister A. Biochemistry of amino acids, the lane with English, page 409, M., 1961; The carbohydrates, ed. by W. Pigman, p. 543, N. Y., 1957; Handbuch der Pflanzen-pliysiologie, hrsg. v. W. Ruhland, Bd 6, S. 761, B. u. a., 1958.
I. B. Friedland.