Angiotensin-converting enzyme is a biologically active substance contained in the human body and is involved in many physiological reactions. In particular, it regulates water-salt metabolism and controls blood pressure, narrowing or dilating blood vessels. Therefore, it is extremely important to control its work, especially for older patients, because it is they who suffer most from high blood pressure and its sharp fluctuations.
ACE Overview
Angiotensin-converting enzyme is actively involved in the metabolism. He does this by influencing the so-called renin-angiotensin system, which is also responsible for regulating blood pressure.
The mechanism of action of the enzyme is quite complicated. If you describe it in a nutshell, it consists in influencing the process of conversion of angiotensin-I to angiotensin-II, which has biologically active properties. In particular, it directly affects the level of blood pressure and contributes to its increase, narrowing the blood vessels. It is because of its main function of converting one angiotensin into another that the enzyme considered in the article got its name.
If we talk about where the angiotensin-converting enzyme is produced, then there are two main places of its synthesis in the body: lung tissue (the main place of occurrence) and renal tubules (in a small amount). After synthesis, the substance is evenly distributed in almost all body tissues.
Indications for the diagnosis of activity
According to the level of activity of the angiotensin-converting enzyme, experts conclude the presence or absence of certain diseases, far from all of which are associated with blood pressure. We can talk about such ailments:
- Sarcoidosis
- Respiratory diseases such as bronchitis and pulmonary fibrosis.
- Rheumatoid arthritis.
- Chronic liver or kidney disease.
- Amyloidosis.
- Diabetes mellitus, etc.
In some cases, the analysis is prescribed to monitor the effectiveness of angiotensin-converting enzyme inhibitors. This is rare enough, but for a patient whose health may depend on the drugs of this group, analysis becomes a very important diagnostic procedure.
Drugs that affect angiotensin-converting enzyme
ACE inhibitors are the most popular group of drugs that are used to control blood pressure in people around the world. They are both medicines for emergency therapy (Captopril), and drugs for treatment courses (Enalapril, Lisinopril). The essence of their action is that they slow down the production and effect of ACE on angiotensin-I, not allowing it to turn into an active form and, accordingly, do not allow an increase in blood pressure.
Study preparation
Analysis for angiotensin-converting enzyme does not require any serious preparation steps. The enzyme is determined in venous blood, so preparation for blood sampling is carried out according to standard recommendations for any such study:
- The patient should donate blood only on an empty stomach, in connection with which he is advised to refrain from eating 12 hours before going to the laboratory to conduct a blood sampling procedure.
- It is necessary to exclude smoking and alcohol intake a day before blood sampling, as these substances can affect the level of the enzyme.
- It is necessary to avoid stress, since the reaction to nervous tension can affect a variety of body functions, for example, increasing the effect of ACE on pressure.
In what cases is the level of ACE increased
When a patient develops the diseases described above (sarcoidosis, respiratory diseases), the amount of angiotensin-converting enzyme in the blood increases significantly. However, sarcoidosis is currently the main reason for which an analysis may be prescribed.
The exact etiology of the disease is still unclear, but it is known that when sarcoidosis occurs in the lymph nodes, granulomas producing ACE begin to appear. A significant increase in the level of the enzyme can be fixed and used as a diagnostic sign in identifying the disease.
With significant deviations of the ACE level, the doctor prescribes additional diagnostic procedures to confirm or deny the alleged diagnosis. Therefore, based on only one analysis, it is impossible to say with accuracy about the presence of such a serious disease as sarcoidosis in a patient.
Norm of angiotensin-converting enzyme
To interpret the results of the analysis, it is necessary to know the normal values for the enzyme. The analysis should show the results displayed in units of units / liter.
Enzyme rates in patients of different age categories are different. The value for children under 12 years old is from 9.4 to 37 units / liter. Adolescents 13-16 years old already have slightly less active ACE in their blood. For them, the norm is from 9.0 to 33.4 units / liter. For adults, values from 6.1 to 26.6 units / liter are considered good indicators.
Is high ACE always a marker for serious illness?
The answer to this question depends on how much the norm is raised. In the case of sarcoidosis, ACE is significantly increased, since granulomas are actively produced in the body. A slight increase may indicate the presence of respiratory tract diseases (including bronchitis), rheumatoid arthritis, diabetes and many other diseases. It is important to know that the level of ACE is not the only factor by which the doctor makes a conclusion about the presence of a disease.
Any patient whose values of this indicator are too high should undergo additional specific diagnostics. With the help of these studies, doctors make the final diagnosis.
Why the level of enzyme activity can be increased
For a long time, doctors could not pinpoint the reasons why some people have excessively high levels of ACE, while others have no problems with this enzyme.
However, recent studies of geneticists in this direction have revealed the angiotensin-converting enzyme gene. This is the so-called ACE gene, which appears due to a small mutation and causes increased synthesis of ACE in the body.
This gene contributes to the appearance of not only high blood pressure, but also many other cardiovascular pathologies. This pathology can manifest itself at any age. However, researchers with great caution draw any conclusions from their discovery, since repeated experiments gave very conflicting information.
In particular, some scientists found the dependence of the ACE level on gender or race, while others did not reveal such a dependence. Therefore, scientists suggest that for more accurate research results, an additional criterion may be required to filter out factors that influence the course of the experiment.
But difficulties with accurate results do not diminish the hope that soon the reasons for the increase in the angiotensin-converting enzyme in the human body will be clarified. Perhaps in the future, gene therapy will help people in the treatment of diseases such as arterial hypertension and angina pectoris. At the present stage, these diseases are treated exclusively by symptomatic therapy. If the reasons for the increase in the level of ACE in the blood are established, patients can get rid of their problems after passing one short course of treatment.