GAPTOGLOBIN

From Big Medical Encyclopedia

GAPTOGLOBIN (Greek hapto to bind, attach + lat. globus a ball) — a serum protein, a glycoprotein, one of characteristic properties to-rogo is ability to form the complex connection having peroksidazny activity with hemoglobin of blood.

Plays an important role in interstitial exchange of iron, connecting it at an erythrocytolysis. Connects the hemoglobin of blood which is released at fiziol, or patol., hl. obr. intravascular, hemolysis. The formed coarse complex hemoglobin — gaptoglobin does not pass through the renal filter, and collapses in cells of retikulo-histiocytic system with release of molecular iron, a cut then is transferred by means of transferrins of blood to marrow — the place of formation of erythrocytes.

Believe that G. takes part in metabolism of vitamin B 12 .

It is open in 1938 by Polonovsky and Zhel (M. for Polonovski, M. F. Jayle) who, studying peroksidazny activity of hemoglobin, revealed the serum protein forming a strong complex with a globin.

G. in a liver is synthesized, on electrophoretic mobility belongs to alfa2-globulinovy fraction. Apprx. 1/4 of its molecules it is formed by polysaccharides.

G.'s maintenance in blood serum of healthy people fluctuates from 50 to 90 mg of %, making 1,2 — 1,4% of total quantity of proteins of serum. By the time of the birth of the child G., as a rule, is not defined that, apparently, is explained by his insignificant contents. By 7th day of life level G. becomes normal.

For quantitative definition of G. in blood serum use methods of an electrophoresis (in starched, agar and poliakrilamidny gels, cellulose acetate, on paper), a size-filtration method on sephadex, a rivanolovy method, and also the methods based on distinction of peroksidazny activity of hemoglobin and a complex hemoglobin — gaptoglobin.

Level G. decreases in proportion to intensity of an erythrocytolysis. But gemoglobinsvyazyvayushchy ability of G. is not boundless. Formation of a complex gaptoglobin — hemoglobin happens in strictly certain ratios: 1000 mg of G. connect 875 mg of hemoglobin at fluctuations of pH from 3,5 to 11,0.

At increase in intensity of hemolysis and substantial increase of level of hemoglobin of plasma the last cannot be connected by G. any more and is allocated with urine.

There are three types G. differing on a pier. to the weight which are descended. Inheritance of types G. (Nr) depends on a combination of two autosomal genes — Nr 1 and Nr 2 that defines phenotypes of Nr 1-1, Nr 2-2 and Nr 2-1.

Find phenotypes of Nr in Europeans 2-1 and less often than Nr 2-2 more often, inhabitants of Africa and Indians of America have a type of Nr 1-1. The population of the Soviet Union has a phenotype of Nr 2-1 more often, 2-2 and less others are more rare the phenotype of Nr 1-1 is widespread.

Communication between genetic systems of inheritance physical is supposed. - chemical properties of the main substance of connecting fabric and properties G., and also between distribution of types G. and prevalence of a number of diseases. In particular, at patients with hemophilia more often than is normal, the phenotype of H r 1-1 meets. Patients with inborn diseases have a c. the N of page — Nr 1-1, at patients with tumoral diseases is systems of blood — a phenotype of Nr 2-2.

G.'s maintenance sharply increases at infectious diseases and at the processes connected with defeat of connecting fabric. Diagnostic and predictive value of increase in maintenance of G. at patients with rhematoid polyarthritis, rheumatism is emphasized; and this increase is proportional to activity and prevalence of process and acceleration of sedimentation of erythrocytes and difenilaminovy test is more constant sign, than. Level G. in blood serum is increased at patients with a myocardial infarction, with damage of a liver, especially in an acute stage of infectious hepatitis. At patients with an aggravation hron, hepatitises and with severe forms of cirrhoses of a liver level G. is reduced, and at cholelithiasis is increased therefore G.'s definition can serve as differential diagnostic test at mechanical and parenchymatous jaundices. At the progressing damage of kidneys (nephrites, nefroza) substantial increase of level early comes to light. At leukoses G.'s maintenance is defined by interaction of two factors: the neoplastic nature of leukemic process promotes increase in level G., accession of a hemolitic component — to decrease it. According to Markolongo (R. Marcolongo), G.'s increase at acute leukoses and a lymphogranulomatosis depends on a stage of a disease and weight of a course of process and has predictive value. Level G. at cancer tumors increases gradually; at innidiation or accession of infectious complications sharply raises.

Gaptoglobin in the medicolegal relation

G. investigate at judicial proceedings of an origin of children (a doubtful paternity, motherhood, replacement of children), for examination of material evidences with spots of blood. There are data on use of changes of level G. in blood for establishment of a cause of death and prescription of its approach.

The main types of Nr 1-1, Nr 2-1 and Nr 2-2 are genetically determined and are descended according to certain patterns — the child can have no type G., to-rogo is not present at least at one of parents. The possibility of an exception of paternity on type G. is presented in the table.

If both parents have type of Nr 1-1, then they can have children only with type of Nr 1-1, and at parents with type of Nr 2-2 — children only with type of Nr 2-2; if one of parents has type of Nr 2-2, and the second — Nr 1-4, then all their children will have type of Nr 2-1.

At examination of disputable motherhood (when the possibility of the birth of the child from the specific woman is established) types of Nr are also considered. So, the woman with type of Nr 1-1 cannot have the child with type of Nr 2-2 and, on the contrary, at the woman with type of Nr 2-2 cannot be the child with type of Nr 1-1.

For establishment of accessory of blood on material evidences establish types G. in spots of blood. At the same time extraction of spots of blood is made the solution containing urea. G.'s ability connect to hemoglobin can be used for confirmation of availability of blood in spots: add to the extract made of the studied spot. In the presence of blood its hemoglobin will connect to G. and at an electrophoresis the characteristic foregramma will be found, i.e. strips of a complex hemoglobin — gaptoglobin will come to light. In the absence of hemoglobin in an extract in the studied spot of such foregramma it is not observed.

OPTIONS OF INHERITANCE OF THE GAPTOGLOBINA TYPES


Bibliography: Lazurenko I. S. Gaptoglobin and technique of his definition, M., 1968; Nikolenko O. V. To Definition of types of a gaptoglobin in spots of blood, Court. - medical examination, No. 2, page 31, 1972; Prokhurovskayaz. I. and M about in-sh about in and the p B. L. Metodika and diagnostic value of definition of a gaptoglobin, Laborat, business, No. 6, page 333, 1972; Sta-rostinn. N of an icherkovskiya. H. Qualitative and quantitative test of gaptoglobin of blood of the person, in the same place, No. 4, page 200, 1966; Tumanov A. K. Serumal systems of blood, M., 1968; Harris G. Fundamentals of biochemical genetics of the person, the lane with English, page 79, M., 1973.

L. G. Kovalyova; A. K. Tumanov (court.).

Яндекс.Метрика