From Big Medical Encyclopedia

LACTOSURIA (lactose + grech, wetting uron) — emergence in urine of lactose (lactose).

At the heart of L. relative insufficiency or decrease of the activity of lactase lies (see. Galactosidases ) — the enzyme splitting lactose (see) in microvillis of a mucous membrane of a small bowel to monosugars, and also organic lesion of cells of a mucous membrane of a gut and increase in permeability of its wall. Not hydrolyzed lactose, being absorbed through a wall of a gut, appears in blood, and then it is completely excreted in urine since its return reabsorption in renal tubules does not occur. Toxic damage of renal tubules by lactose leads to development aminoacidurias (see) and proteinurias (see).

Normal lactose can be found in the minimum quantities in urine. L. at the feeding women during the period lactations (see) is physiological. L. at newborns is the first 10 days of life and premature children disappears with increase in a lactase activity. Alimentary L. at babies is passing and disappears with reduction of consumption of milk.

L. can be one of symptoms of disakharidazny insufficiency with the lactose intolerance arising at inborn deficit of lactase. The disease develops at children from the moment of the birth after reception of milk and is characterized by development of the dispepsichesky phenomena of varying severity (see. Malabsorption syndrome ).

L. it is observed at such diseases of intestines as toxic dyspepsia, enterita of various etiology, ulcer nonspecific colitis, the Kwasiorkor, a mucoviscidosis, a Gee's disease, at a lambliasis, after an enterectomy. In these cases of L. has temporary (tranzitorny) character and disappears in process of treatment of a basic disease. Cases of L are described. at phrenic hernias and burns when wounds were processed by the substances containing lactose: lactose was absorbed from a surface of burns and excreted by kidneys.

Lactose in urine can be identified by qualitative and quantitative methods. Treat qualitative: 1. The Fenilozazonovy test based on ability mono - and disugars to form almost insoluble crystals in water with phenylhydrazine; it is used for identification of glucose and lactose in a form of crystals. 2. Velk's test — Malfatti, edges is in what to 5 ml of urine is added by 2 — 5 ml konts. solution of ammonia and 5 drops of 10% of caustic alkali also heat in the water bath within 30 min. at t ° 60 °. In the presence of lactose urine is painted in red color (glucose gives brown coloring). 3. Kolmer's test — Bernera with formation of a white deposit. The test is positive for a galactose and lactose. In urine apply hromatografichesky methods to quantitative definition of lactose (see. Chromatography ), method of high-voltage electrophoresis (see) and a specific enzymatic method with a beta galactosidase.

Treatment at an inborn lactose intolerance includes a dietotherapy with restriction or a complete elimination of milk and use of delactosed milk mixes; at tranzitorny L. treatment of a basic disease is carried out.

Bibliography: Badalyan L. O., Tabolin V. A. and In e of l t and shch e in Yu. E. Hereditary diseases at children, page 104, M., 1971; P and che in L., Todorov Y. and Statevas. A metabolism at children's age, the lane с^болг., page 287, Sofia, 1967; Todorov Y. Clinical laboratory trials in pediatrics, the lane with bolg., page 95, Sofia, 1968; D u r a n d P. Lactosurie et saccharosurie, in book: Moderne Probi, d. Padiat., hrsg. v. A. Hottinger u. H. Berger, Bd 4, S. 496, Basel — N. Y., 1959; Holzel A., Schwarz V. Sutcliffe K. W. Defective lactose absorption causing malnutrition in infancy, Lancet, v. 1, p. 1126, 1959; Kolmer J. A. a. BoernerF. Approved laboratory technics,> p. 152, N.Y., 1941; M a 1-f t t i H. Uber den Nachweis von Milch-zucker in Harne, Zbl. Krankh. Harn-u. sex. Organe, Bd 16, S. 68, 1905; Metabolic, endocrine, and genetic disorders of children, ed. by Y. C. Kelley, v. 2, p. 761, Hagerstown, 1974.

Yu. A. Knyazev, H. P. Filina.