Functions and diagnostic importance of some fractions of proteins Table 11 Biologic and clinic importance of blood serum proteins

Fractions	Functions	Diagnostic importance
Albumins (A)	1) Ponc; 2) transport of FFA, bilirubin; hormones, iones and drugs	↓ A is in diseases of liver (↓ of synthesis) and kidneys (↑ of secrertion) => edema, toxic appearance
α-globulins	Transport of copper, lipids, Hp, Ing of proteases	↑of α-globulins in acute inflammation
β-globulins	Transport of iron and cholesterol	↑ of β-globulins is in chronic inflammation
γ-globulins	Humoral immunity	↑ of γ-globulins is in chronic inflammation of infectious and autoimmune diseases ↓ γ-globulins is in immunodeficiency

There are secretory, excretory and indicatory enzymes of blood plasma. Secretory enzymes are thrombin and plasmin. Excretory enzymes are leucine aminopeptidase and alkaline phosphatase; indicatory are LDH, ALT, AST, GGT etc. Secretory enzymes are formed in blood plasma. Excretory enzymes are formed in bile and eliminated through large intestine with feces. In cholelithiasis (bile stone disease and other reasons of cholelithiasis) these enzymes increase in blood plasma indicationg the site of damage – biliary tract. Indicatory enzymes are located in cells. In the case of damage they exit into blood stream, showing the location of damage. For example, ALT and AST are increased in hepatitis and myocardium infarction, muscular trauma. GGT are increased in cancer of pancreas, cholelithiasis, diseases of kidneys. Creatine kinase is increased in myocardium infarction and muscular pathology. LDH1 is located in heart, LDH2- in heart and kidneys; LDH3 - in lungs; LDH4 and 5 – in liver and skeletal muscles

Residual nitrogen includes urea (3-9mM/L); creatine (15-70mcM/L); creatinine (60-130mcM/L); total bilirubin 8-20mcM/L; uric acid (0.2-0.5mM/L). Increase of creatine is observed in infarction of myocardium, traumas, after operations, myodystrophy. Creatinine is an indicator of chronic renal falure. Total bilirubin is increased in jaundices. Indirect bilirubin is increased in hemolytic anemia and hepatitis. Direct bilirubin is increased in hepatitis and mechanic jaundice. Uric acid is increased in gout (podagra).

Increase of residual nitrogen may be retentional and productional. First one may be renal and extrarenal (hypotension, low blood pressure). Productional one is observed in increase of catabolism of proteins in traumas, after operations, in diabetes mellitus, starvation, neoplasm, hemolysis).

Kinins

Kinins are local hormones. They aren’t synthesized in endocrine glands but are formed in blood plasma from inactive precursors. Kinins are formed from kininogens. There is a prekallikrein. Under influence of adrenalin, trypsin, XII factor of blood clotting the activation of its to kallikrein occurs. Kallikrein activates kininogens to according kinins. There are kallidinogen and bradykininogen therefore kallidin and bradykinin are formed. Kallidin and bradykinin are kinins and consist of 9 amino acids. They’re biologically active substances and carry out next functions:

1. increase of permeability and dilation of vessels (hypotension)

2. they are inflammatory mediators because increase permeability of membranes

3. they form pain sense

4. they take part in allergy and constrict bronchi

5. they promote secretion of sweat, saliva, HCl, intestinal juice. It is supposed that increase of kinins leads to ulcer disease

6. decrease of kinins is one of reasons of hypertensia