SHYONKHEYMERA METHOD (R. Schoen-heimer, amer. doctor. sort. in 1898) — a method of definition in blood serum of free and esterified cholesterol. The method is used as additional diagnostic test at diagnosis of atherosclerosis (see), a hypothyroidism (see), a nephrotic syndrome (see), diseases of a liver, various disturbances of a lipometabolism (see), etc.
Principle of a method. Cholesterol is extracted ether alcohol: in one part of extract determine the general content of cholesterol (the general cholesterol), in another — the content of ester of cholesterol (esterified cholesterol) after sedimentation of free cholesterol by digitonin, then calculate the content of free cholesterol (a difference between the content of the general and esterified cholesterol).
Course of definition. In a volumetric flask on 25 ml pour 15 ml of ether alcohol (3:1), stirring up, add 1 ml of blood serum on drops. Put for 1 min. in the boiling water bath and well mix. Cool, bring to a tag mix of alcohol and ether, filter. The filtrate is collected in a bottle, to-ruyu densely corked.
Definition of the general cholesterol:
5 ml of a filtrate, the corresponding
0,2 ml of blood serum, heat in a test tube on the water bath to full evaporation and formation of a solid residue. Cool and at strong stirring add in the small portions 10 ml of chloroform. Then filter also to 5 ml of a filtrate, the corresponding 0,1 ml of blood serum, add 2 ml of acetic anhydride and 5 drops the concentrated chamois to - you, slightly stir up, cork up and leave to stand in the dark place precisely 30 min., during to-rykh the developing green coloring reaches the greatest intensity. Kolo to a rimetrir yut (see Colorimetry) at 720 nanometers (the red light filter) in a ditch with thickness of a layer of 5 mm. Calculation of content of cholesterol is made according to the calibration schedule constructed with use of standard solutions of cholesterol.
Definition of esterified cholesterol: 10 ml of a filtrate, the corresponding 0,4 ml of blood serum, heat on the water bath to disappearance of a smell of ether, add
1 ml of 1% of solution of digitonin, slightly stir up and continue to evaporate before receiving a solid residue. Cool and add in the small portions 10 ml of chloroform, stirring up at each addition, filter. From a filtrate take 5 ml corresponding to 0,2 ml of blood serum then define concentration of ester of cholesterol the same as it is described above during the definition of concentration of the general cholesterol.
Concentration of free cholesterol makes a difference between concentration of the general cholesterol and concentration of esterified cholesterol.
The normal amounts of content of esterified cholesterol in blood serum determined by Sh. by m make 90 — 135 mg! 100 ml, free cholesterol — 40 — 70 mg! 100 ml.
Bibliography: D to P. and
Peunesku E. zhordzhesk. Biochemical methods of the diagnosis and a research, the lane from Romanians., page 168, Bucharest, 1963; Schoenhei-mer R. Sperry W. M. Micromethod for determination of free and combined cholesterol, J. biol. Chem., v. 106, p. 745, 1934. JI. M. Pimenova.