Lipidogram - a graphic image of the quantity and quality of serum lipoproteins, obtained by their electrophoretic distribution on paper.
Blood serum before electrophoresis (see) is most often stained by Sudan with black, revealing the lipoproteins visually contained in it. On lipidograms there are three main zones. The first is in the area of α-globulins (α-lipoproteins), the second is in the area of β-globulins (β-lipoproteins), the third is at the site of application of serum to a filter paper tape (in the ү-globulin zone); in this last zone, the lipoproteins do not move under the influence of electrophoresis and are called the zero fraction, or prelipoproteins (Fig.). The fractions of lipoproteins, since they do not strictly coincide with the protein fractions, are denoted by the numbers I, II, III or the letters A, B, C.
α-lipoproteins contain about 66% of phospholipids and about 33% of cholesterol, β-lipoproteins – cholesterol 56% and phospholipids 44%.
Prelipoproteins contain predominantly neutral fats. Normally, the content of α-lipoproteins is 13.0–29.3%, β-lipoproteins - 34.6–50.3%, and prelipoproteins - 29.0–46.8%. Attitude
β-lipoproteins / α-lppoprotepdy = 1.3-3.4.
The percentage of different fractions of lipidograms is determined by densitophotometry, by elution followed by photometry (see Photometry), and also by planimetric. Lipidograms can be used as an additional criterion for the differential diagnosis of a number of diseases (acute hepatitis, liver cirrhosis, congestive jaundice, etc.), in which there is a differential decrease in the α-fraction. An increase in predominantly the B-fraction is observed in chronic hepatitis. Very characteristic changes in lipid profile in children with nephrosis, especially in lipid nephrosis. An increase in prelipoproteins is observed in atherosclerosis. It is believed that the definition of prelipoproteins can be used in a mass survey of the population to identify the spread of this disease.
See also Electrophoresis (electrophoretic studies).
Proteinogram (I) and lipidogram (II) of the blood serum of a healthy person. Proteinogram (III) and lipidogram (IV) of the patient's serum after myocardial infarction; p - β1 - pathological strip.