LDH (lactate dehydrogenase): normal in the blood, increased - reasons

Distribution of fractions in plasma. Age and norm

content of LDH fractions in organs

The first fraction (LDH-1 or HHNN tetramer) originates primarily in the cardiac muscle and is significantly increased in the blood serum with myocardial damage.

The second, third, fourth fractions (LDG-2, LDH-3, LDH-4) begin to actively enter the plasma under pathological conditions accompanied by massive death of blood platelets - platelets, which occurs, for example, in the case of such a life-threatening condition as pulmonary embolism (PE).

The fifth isoenzyme (LDG-5 or MMMM tetramer) comes from the cells of the liver parenchyma and is released into the blood plasma in large quantities at the acute stage of viral hepatitis.

Due to the fact that different types of tissue accumulate and release different concentrations of LDH, fractions of lactate dehydrogenase isoenzymes are distributed unevenly in the blood plasma:

The activity of lactate dehydrogenase in red blood cells (erythrocytes) is 100 times higher than the levels of the enzyme contained in the blood plasma, and increased values ​​​​are observed not only in pathological conditions, but also in a number of physiological conditions, for example, pregnancy, the first months of life or excessive physical effort on their part also contribute to an increase in LDH activity. Significant differences in the normal levels of this indicator are also due to age and gender, as evidenced by the table below:

Meanwhile, the normal values ​​for blood LDH are always approximate; they should not be memorized once and for all for the reason that the analysis can be performed at a temperature of 30°C or 37°C, the level is calculated in different units (μkat/l, mmol/( h·l), U/l or U/l). But if there is an urgent need to independently compare your own results with the normal variants, then it will be useful to first inquire about the institution that performed the analysis, the methods of its implementation and the units of measurement used by this laboratory.

Excretion of lactate dehydrogenase isoenzymes (LDH-4, LDH-5) by the kidneys does not exceed the level of 35 mg/day (excretion rate).

Reasons for increased LDH

The level of LDH activity is increased in almost any pathological process that is accompanied by inflammation and death of cellular structures, therefore the reasons for the increase in this indicator are primarily considered to be:

• Acute phase of myocardial infarction (a more detailed description of changes in the LDH spectrum during necrotic myocardial damage will be presented below);
• Functional failure of the cardiac and vascular system, as well as the respiratory system (lungs). Involvement of lung tissue in the process and the development of circulatory failure in the pulmonary circulation (LDH levels are increased due to the activity of LDH-3 and, to some extent, due to LDH-4 and LDH-5). Weakening of cardiac activity leads to circulatory disorders, symptoms of congestion and an increase in the activity of LDH-4 and LDH-5 fractions;
• Damage to red blood cells (pernicious and hemolytic anemia), causing a state of tissue hypoxia;
• Inflammatory processes affecting the lungs, as well as the renal or hepatic parenchyma;
• Pulmonary embolism, pulmonary infarction;
• Acute period of viral hepatitis (in the chronic stage, LDH activity, as a rule, does not leave the normal range);
• Malignant tumors (especially those with metastasis), localized mainly in the liver tissue. Meanwhile, a strict correlation, in contrast to myocardial infarction (the larger the size of the lesion, the higher the activity of LDH) between the progression of the oncological process and changes in the spectrum of lactate dehydrogenase is not traced;
• Various hematological pathologies (polycythemia, acute leukemia, granulocytosis, chronic myeloblastic leukemia, anemia caused by vitamin B12 deficiency or lack of folic acid);
• Massive destruction of platelets, which is often caused by blood transfusions that are not provided with sufficient selection for individual blood systems (for example, HLA);
• Diseases of the musculoskeletal system, primarily damage to skeletal muscles (injuries, atrophic lesions, mainly at the initial stage of disease development).

Design and technical features of the equipment

The LDG-5 25 huller is a structurally productive and practical development. Allows you to get high performance and long life. The device is able to work efficiently even in abnormal conditions. Effective components are made of high-quality, wear-resistant materials.

They are located in four separate sections, at an angle to the base being processed. And one section of the ceiling. This design characteristic allows you to obtain the quality of continuous processing, without gaps. The device is connected to the hydraulic system of the tractor. Easily transforms from a moving position to a working position.

We recommend: How does the LDG-8 huller work?

Main advantages of PPL 5 25:

1. A variety of areas of use with high productivity.
2. Low cost of use.
3. Simple design with a minimum number of adjustment points.
4. Large disc seats with reliable bearings that do not require maintenance.
5. Possibility to choose among several types of rear rollers.
6. The high pressing force of each disc allows you to obtain the required penetration into the soil.
7. Low level of vegetation contamination.

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Publication from Belagromash-Service (@belagromash2020) May 22, 2021 at 9:36 PDT

LDH and cardiac muscle necrosis

The study of the glycolytic enzyme has a very important diagnostic value in case of damage to the heart muscle, therefore it is one of the main enzymatic tests that determine myocardial infarction on the first day

development of a dangerous necrotic process localized in the heart muscle (8–12 hours from the onset of pain). The increase in enzyme activity occurs, first of all, due to the LDH-1 fraction and partly due to the second fraction (LDH-2).

After a day or two from a painful attack, the level of LDH in the blood reaches its maximum values ​​and in most cases remains highly active for up to 10 days. It should be noted that activity is directly dependent on the area of ​​myocardial damage

(the larger the size of the lesion, the higher the indicator values). Thus, myocardial infarction, initially diagnosed using laboratory tests such as determination of creatine kinase and the MB fraction of creatine kinase, can be confirmed within a day by this enzymatic test (LDG is elevated and increased significantly - 3 - 4 ... up to 10 times).

In addition to increasing the total activity of lactate dehydrogenase and increasing the activity of the LDH-1 fraction, the LDH/LDH-1 or HBDG (hydroxybutyrate dehydrogenase) ratio and the LDH-1/LDH-2 ratio are of particular value for detecting acute myocardial infarction. Considering that the GBDG values ​​in the acute period of the disease change significantly upward, and the total activity of lactate dehydrogenase will be reduced relative to the rather high LDH-1 values, the LDH/GBDG ratio will noticeably drop and will be below 1.30. At the same time, the LDH-1/LDG-2 ratio, on the contrary, will tend to increase, tending to reach 1.00 (and sometimes even cross this line).

Functionality and profitability of equipment

The hydroficated disk huller LDG-5 is a highly efficient development of Ukrainian production. Performs surface treatment of soil to a depth of up to 15 cm.

It is used when processing soil for agricultural purposes after the main harvest, in fields where there is a huge amount of vegetation. It is successfully used for pre-sowing treatment, which improves the quality of plowing. Effectively handles fallow areas.

The use of technology improves the quality of the soil, eliminates erosion and weathering, and enhances exchange activities. The disk huller marked 5 operates with soil of different densities.

It effectively loosens it and is successfully used in conditions of high humidity. The device cuts off the roots of weeds, crushes decaying remains, and forms mulch.

During operation, the equipment mixes it with soil to the depth and width of the treatment. It makes the relief of the treated areas even, breaks up blocks, and eliminates insect larvae throughout the entire depth of influence. Using this technique, the soil is saturated with moisture, ensuring its preservation. The quality of the land and its fertility are improving.

Other reasons for changing odds

The above parameters, in addition to necrotic damage to the heart muscle, are also subject to changes in the case of other serious diseases:

• Hemolytic anemia of various origins (LDG/GBDG decreases and becomes below 1.3);
• Megaloblastic anemia (the content of the first fraction significantly exceeds the concentration of the second);
• Conditions accompanied by increased cell destruction (acute necrotic process);
• Neoplasms localized in the glands of the female and male reproductive system: ovarian dysgerminoma, testicular seminoma, teratoma (here only an increase in the concentration of LDH-1 is noted);
• Renal parenchyma lesions.

Thus, the main culprits, and therefore the main reasons for changes in the concentration of the described indicators in the blood serum, can be considered conditions associated with the destruction of liver and kidney parenchyma cells, as well as blood cells (platelets, erythrocytes).

Some nuances

To study LDH in the blood, 1 ml of serum is sufficient, which is obtained from blood donated, as for any other biochemical test, in the morning on an empty stomach (however, if there is a question about diagnosing acute MI, then these rules, of course, are neglected).

In a laboratory study of LDH, hemolysis leads to distortion of the analysis results (overestimates them). And when exposed to heparin and oxalate, the enzyme activity in the serum, on the contrary, will be reduced compared to the real blood LDH values. To prevent this from happening, you should start working with the material as early as possible, first of all separating the clot with formed elements from the serum.

Reliable and simple

Pupil LDG-5 is highly reliable and easy to use. The discs optimally follow the contour of the soil. At the same time, the unit is easy to assemble and maintain. The service life of the model is at least seven years, but in fact, with proper care, the service life of the unit is more than 10 years.

Another indisputable advantage of the LDG-5 hoe is the excellent suspension of the discs to the frame. Each disc is mounted individually, securely attached to the frame. During operation, the disc hoe shows good results even on rocky soils.

Well-attached spherical discs pass through stones, small obstacles, and the roots of large weeds without being damaged. They do an excellent job of peeling and plowing the top layer of soil.

LDG-5 has established itself as a simple and effective machine for soil hulling.

This compact device has a working width of 5 m, while the discs are capable of cutting and mixing the earthen bank to a depth of 10 cm. Thus, the compact device contains all the necessary requirements for ploughers.