Protein metabolism

Processes deamination, transamination and synthesis of amino acids, albumin, and most of the serum globulins blood protrombina and fibrinogen occur in the liver. Assume that albumin and alpha-globulins are produced polygon liver cells, b -, and V-globulins are formed in RES, in particular in coppersky liver cells and plasma cells in the bone marrow.
The leading role of the liver in protein metabolism explains the great interest of clinicians to methods of determination of indicators of this exchange. These include primarily the determination of the total plasma protein and its fractions, including prothrombin. Along with the definition of proteinogram are of practical use and samples, indicating only indirectly for changes in the proteins of blood, including the manifestation of the pathological protein paraproteins. These are the tests lability and colloidal samples.
The total amount of protein in the plasma of healthy people is 7.0-8.5 per cent (K. I. stepashkina, 1963). The change in the total quantity of protein is observed only in severe violation of protein metabolism. In contrast, the change in the ratio of individual fractions is very thin indicator of the metabolism of proteins.
The widest application in practice has the determination of protein fractions by electrophoresis on paper. The disadvantage of the latter are the variations in results, depending on which version of the method. Therefore literary data about normal proteinogram not identical.
In table. 7 variants norms, described by various authors (by C. E. Baptist, 1960).
When liver damage is reduced albumin synthesis and A1-globulin polygon in the liver cells, and the synthesis of b - and V-globulin in coppersky cells and periportal mesenchymal cells increases (as a manifestation of irritation cells reticuloendothelial), resulting in quantitative changes of protein fractions - dysproteinemia.
For diffuse liver damage, both acute and chronic are in the period of exacerbation, is characterized by the following changes in proteinogram: drop in the amount of albumin and increased globulins. Regarding the latter, mainly increases ' -globulin fraction, apparently, by the accumulation of antibodies, similar in electrophoretic mobility with ' -globulins. Less content raises the A2 - and?-globulin. The degree of change in proteinogram is in direct proportion to the severity of the disease. The exception is agammaglobulinemia in hepatic coma. The total amount of protein is usually somewhat increased due to hyperglobulinemia.
Assessing proteinogram in patients with liver disease should not forget that a large number of the most various diseases considerable changes protein fractions, such as when collagenoses, kidney damage, multiple myeloma and other
For liver changes in the coagulation of blood, and the definition of various factors of blood coagulation is a test to evaluate the functional state of the liver. The most characteristic changes protrombina and prokonvertina.
Prothrombin (II coagulation factor) is globulin, in an electrophoretic study of plasma prothrombin peak is located between albumin and ' -globulins. Formed prothrombin in the liver cells, with the participation of vitamin K. In the clotting of blood prothrombin turns into thrombin. Concentrations of prothrombin in the blood plasma is about 0,03%. Practically determine not the absolute number of prothrombin, and "prothrombin time and prothrombin index. The most widespread in the Soviet Union method of determining prothrombin index is a method Century N. Tugolukov there (1952). Normal prothrombin index is 80-100%.
The ability of hepatocytes to the synthesis of protrombina in liver pathology can be broken. In addition, the liver accompanied by a breach of the Deposit of its range of vitamins, including vitamin K, which is also the reason gipoprotrombinemii. Therefore, in case of detection of lowering prothrombin index should be re-survey after the 3-day loading vitamin K - 0.015 vikasola 3 times a day. If the number of prothrombin remains low, this indicates the parenchymal liver.
Another factor of the blood coagulation system, naturally respond to the defeat of the liver is proconvertin (factor VII, stable factor). Proconvertin catalyzes action thromboplastin, accelerating the formation of thrombin. This factor is formed in the liver, its content in plasma is 0,015-0,03%. The number prokonvertina as protrombina, expressed as an index. Time prokonvertina is normal 30-35 seconds index - 80-120%.
When parenchymal liver fall as prothrombin index, and the index prokonvertina. There is a parallelism between these indicators and the severity of the liver injury (K. G. Kapetanaki and M. A. Kotovshchikova, 1959; A. N. Filatov and M. A. Kotovshchikova, 1963).
A number of different methods, indirectly determining the presence of dysproteinemia and paraproteinemia. They are all based on the pathological deposition of protein various reagents.


Sample Takata-Ara (sublimate sample) based on the loss of flocculent precipitate of coarse proteins under the action of reagent Takata containing mercuric chloride. The reaction is measured by the density of the sediment or serum dilution, which came blurred. The sample is assessed as positive if in a series of tubes from the reagent Takata and waning number serum (1,0; 0,5; 0,25; 0,12 ml and so on) flocculent precipitate fall in the first three test tubes; if only in the first two weakly positive. The sample falls positive with the increasing content ' -globulins in the blood, particularly in Botkin's disease, cirrhosis of the liver, but also in a number of other diseases (pneumonia, syphilis and others).
One of the modifications of the sample Takata-Ara is the testing gross (sublimate-sedimentary reaction), in which the results are expressed in milliliters sublimate reagent needed to obtain a clear dimness. The norm is 2 ml or more. With liver disease indicators samples gross decrease to 1.8-1.6 ml, with heavy defeat to 1.4 ml and below.
Trial of Veltman based on coagulation proteins when heated in the presence of calcium chloride solution of various concentrations (from 0,1 to 0,01%). In the normal coagulation occurs when the concentration of the solution is higher than 0,04%, i.e. in the first 6-7 tubes. For liver damage is characterized by the appearance of sediment at lower concentrations - prolongation of coagulation "ribbon".
Test with Catalina based on the occurrence flocculation cephalin-cholesterol emulsion in the presence of the blood serum of the patient. The sample has the advantage before those specified above that falls sharply positive in the presence of necrosis in liver parenchyma and therefore can be useful in determining the activity of the process in Hungary disease and cirrhosis of the liver, and in differential diagnosis between mechanical jaundice (in early stages) and parenchymal liver.
Test thymol turbidity based on the determination of turbidity arising in connection test serum thymol reagent. The turbidity is determined after 30 minutes and is estimated at spectrophotometer or in a colorimeter. Using a standard curve turbidity, get the result in arbitrary units. Rainfall varies from 0,8 up to 5.0% In the defeat liver indicator of samples increases, reaching 30-35 units at Botkin's disease (Popper, Schaffner, 1961).
Sample thymol turbidity can be continued in the form of thymol test flocculation: estimated occulation, the coming 24 hours after the connection serum thymol reagent.

The residual nitrogen in the blood is normal 20-40 mg%. Expressed azotemia (up to 100 mg% or more) meets with severe liver disease (acute degeneration when hepatitis, end-stage cirrhosis, liver failure after operation on a liver and biliary tract) and shows the development of liver failure.
Ammonia serum is in norm 40-100'%. Giperammoniemia observed in liver failure, and in the presence of pronounced Porto kafelnyh anastomoses (developed naturally or created during the operation), in which the blood from the intestines is, bypassing the liver. The most pronounced increase in the amount of ammonia in the peripheral blood is observed in patients with hepatic insufficiency after load protein (eating large amounts of meat intake in the intestine of blood in the esophageal or gastric bleeding). To identify portal and hepatic insufficiency can be applied test with load ammonium salts (A. I. Khazanov, 1968).
Lipoproteins and glycoproteins *. The proteins in the blood serum form stable compounds with lipids and carbohydrates: lipo - and glycoproteins. Naturally, with the change in the ratio of different fractions of plasma proteins change and maintenance of related facilities.
During electrophoresis lipoproteins are divided into fractions corresponding to the 1-,b and V-globulin fractions. To V-cut ("lipid balance") are few moving in an electric field connection protein with a neutral fat and cholesterol esters. This fraction is not practical interest, since the latter does not change in conditions of a pathology. In healthy individuals have the following percentage of alpha - and beta-fractions, lipoprotein (I. E. Tareeva, 1962): alpha-lipoprotein - 29,0 ± 4,9; beta-lipoprotein - 71,0 ± 4,9; attitude β/α-2,45 ± 0,61.
The relation between the change in the ratio of alpha - and beta-lipoprotein fraction and the severity of damage of the liver parenchyma. No full parallelism between changing lipoproteinami and other functional characteristics. However, it should be noted that for Hungary disease and the active phase of liver cirrhosis is characterized by a decrease of the alpha-lipoprotein up to their complete disappearance on lipid profile and increase of b-lipoproteins with a corresponding increase in the ratio β/α several times. In chronic liver these changes were less pronounced.
Glycoproteins connection of different carbohydrates with protein, mainly with globulins. Electrophoretic method enables the separation of fractions of glycoproteins with the corresponding protein fractions. Synthesis of glycoproteins is in the liver, so clear attempt of application of the definition of glycoproteins with the purpose of functional diagnostics. However, the data obtained by various authors for examination of patients with liver disease, remains highly controversial. More typical is the increase of the faction alpha-glycoproteins (N. A. Zaslavskaya, 1961; I. D. Mansurov, V. I. Dronov, and M. S. Panasenko, 1962).

* The method of determining see: A. F. of Bluger. Structure and function of the liver at epidemic hepatitis. Riga, 1964.