What are Catecholamines?

Catecholamines are a neurological substance containing catechol and amine groups. Catechol and amine groups are combined by an enzymatic step of L-tyrosine in the sympathetic nerve, adrenal medulla, and pheochromocytoma. Generally, catecholamines refer to norepinephrine (NA), epinephrine (Adr), and dopamine (DA). All three catecholamines are derived from tyrosine as a precursor.

Drug Name: Catecholamines
Alias: Catechol
Whether prescription drugs: prescription
Main indications: Shock, neurogenic, cardiogenic, septic shock

Dosage: 2 mg in 5% glucose 500 ml
Adverse reactions: Ischemic necrosis
Main medication contraindications: Hypertension, coronary heart disease, arteriosclerosis, etc.
Athletes use with caution: Use with caution

Catecholamines

That is, amine compounds containing catechol (ie, catechol), including dopamine, norepinephrine and epinephrine, and their derivatives. Norepinephrine and epinephrine are both hormones secreted by the adrenal medulla and the nerve mediators of norepinephrine fibers in the sympathetic and central nervous systems. Norepinephrine is widely distributed in the central nervous system, and its content is more, but its content is less. Dopamine is mainly concentrated in the extrapyramidal site and is also a nerve mediator. They are important classic adrenaline receptor agonists. Catecholamines regulate basic physiological functions in the body and transmit physiological signals. They are important signal media in normal physiological processes, and corresponding changes in their contents also occur during pathological processes. It can be used clinically to help diagnose endocrine-related diseases such as hypertension, hyperthyroidism, pheochromocytoma, and neuroblastoma. The chemical structure of catecholamines is characterized by a dihydroxybenzene nucleus and an amino group-containing side chain. The content of catecholamines in biological samples is extremely low ^[1] . ^[2]

Dopamine

Norepinephrine

Epinephrine

Catecholamines explained

Catecholamines (CA) include norepinephrine (NA or NE), epinephrine (Ad or E), and dopamine (DA). The junction between sympathetic ganglion cells and effectors uses noradrenaline as a transmitter . Catecholamines are a neurological substance containing catechol and amine groups. Catechol and amine groups are combined by an enzymatic step of L-tyrosine in the sympathetic nerve, adrenal medulla, and pheochromocytoma. Generally, catecholamines refer to dopamine, norepinephrine, and epinephrine. All three catecholamines are derived from tyrosine as a precursor.

Changes in plasma catecholamine levels suggest different pathological conditions. Two aspects can generally be determined from abnormal catecholamine levels:

Point 1 concerns adrenal medullary tumors, which combine with large amounts of catecholamines to cause circulatory abnormalities.

The second point concerns the cardiovascular system. Excessive levels of catecholamines can cause hypertension and myocardial infarction, and low levels often lead to hypotension. There are also potential links between differences in catecholamine levels and sudden cardiac death and coronary heart disease and heart congestion.

Catecholamine clinical application

Clinical application:

1. Shock, neurogenic, cardiogenic, and septic shock are commonly used in the early stages of dopamine to enhance myocardial contractility and expand peripheral blood vessels to improve microcirculation. Adrenaline is commonly used for anaphylactic shock. Dopamine anti-shock agent

Catecholamines Anabolic The amount should not be too large. Generally, 2 mg is added to 500 ml of 5% glucose, and the intravenous drip rate is controlled at 4-8 micrograms per minute to maintain the systolic pressure at about 90 mmHg.

2. Gastric hemorrhage, 1-3 mg of catecholamines are appropriately diluted and taken orally, and the gastric mucosal blood vessels are contracted due to local effects in the stomach, resulting in hemostatic effects.

Its adverse reactions are: ischemic necrosis of the tissue can occur; so do not let the drug leak out of the blood vessel. Do not overdose; lest acute renal failure occur. In addition, a sudden drop of blood pressure may cause a drop in blood pressure. When the drug is stopped, the dose should be gradually reduced and the drip rate should be slowed down before the drug is stopped.

Catecholamine pathological link

Changes in plasma catecholamine levels indicate different pathological conditions. Two aspects can generally be determined from abnormal catecholamine levels:

Adrenal medullary tumors are involved first, and these tumors combine with large amounts of catecholamines to cause abnormal circulation.

The second point concerns the cardiovascular system. (Catecholamines) excessive levels can cause hypertension and myocardial infarction, too low levels usually lead to hypotension. Different levels of catecholamines are also potentially linked to sudden cardiac death, coronary heart disease, and heart congestion.

When the sympathetic-adrenal medulla system is excited, catecholamines (CA) are released into the blood in large quantities. In various shocks, the CA in the blood is tens or even hundreds of times higher than normal. Norepinephrine and epinephrine excite alpha receptors, causing the skin, abdominal organs, and small vessels in the kidneys to contract, with less blood perfusion and microcirculation ischemia. Epinephrine can also excite receptors, making arteriovenous short circuits open, blood bypasses the real capillary network and enters the venules directly, aggravating tissue ischemia and hypoxia; arteriovenous short circuits of the pulmonary microcirculation open, affecting the arteries of hypoxic venous blood To reduce PaO2.

Catecholamines physiological effects

The main physiological role of catecholamines is to stimulate the alpha receptors of blood vessels, causing them to contract, mainly small arteries and

Synthesis of catecholamines Vein vasoconstriction is more obvious in the skin and mucous membranes; second is the vasoconstriction of the kidneys; in addition, the brain, liver, mesentery, and skeletal muscle blood vessels all have a contraction effect; it has a diastolic effect on the coronary coronary vessels, which is due to cardiac excitement and cardiac metabolism The increase of products such as adenosine increases the perfusion pressure of coronary vessels and increases the principle of coronary flow. Acting on the heart itself, when the release of catecholamines in the body increases, the myocardial contractility increases, the heart rate increases, the stroke volume increases, the systolic blood pressure increases, and the pulse pressure becomes smaller.

1. Effect on the cardiovascular system: Catecholamine acts on the heart through -1 receptors, which accelerates heart rate, increases contractility, increases conduction speed, and increases cardiac output.

2. Effect on internal organs: Catecholamine relaxes smooth muscle through -2 receptor, and contracts it through -1 receptor.

3. Metabolic effect: Catecholamines participate in the regulation of thermogenesis and increase heat consumption through receptors to produce heat. And can promote the decomposition of energy substances stored in the body.

4. Catecholamines have an important role in regulating the volume and composition of extracellular fluid and the metabolism of water and electrolytes.

5. Catecholamines can cause changes in the secretion of renin, insulin and glucagon, thyroid hormone, calcitonin and other hormones. Determination of catecholamine concentration The normal value of plasma norepinephrine is about 0.3 to 2.8 nmol / L (15 ~ 475pg / ml), the normal value of adrenaline is about 170 ~ 520pmol / L (30 ~ 95pg / ml).

Catecholamine analysis method

The chemical structure of catecholamines is characterized by a dihydroxybenzene core and an amino group-containing side chain. The content of catecholamines in biological samples is extremely low. Most literature reports that the content of catecholamines in actual biological samples is very small. Extremely poor stability and susceptibility to oxidation. In addition, various endogenous chemical interferents with similar structures and / or metabolites with the same chemical group are also present in biological samples, leading to accurate determination of catecholamine concentrations in biological samples. It is difficult to determine a specific catecholamine in a biological sample with high selectivity and high sensitivity, such as accurate determination of norepinephrine and / or epinephrine in serum, which is currently a difficult target in clinical practice. At present, related research on the detection and analysis of catecholamines at home and abroad is continuously deepening, and more attention is paid to simple, easy, economical and applicable methods to accurately quantify related substances and can be widely applied.

Catecholamines are closely related to people's health and disease as neurotransmitters. More and more evidence shows that they play different roles in physiological processes, disease occurrence and disease progression. Many clinicians and researchers have paid attention to the research of catecholamines, and the most important research goal at this stage is how to quickly and accurately detect the target substance. The premise to obtain accurate results is to choose a simple and reliable analysis method. There are various methods for detecting catecholamines currently used in laboratories. At present, scholars have focused on the combination of high-performance liquid chromatography with electrochemical detection and fluorescence detection. Method for analysis of catecholamines. At present, these methods have their own advantages and disadvantages. The analysis characteristic of HPLC-electrochemical method is that it can reduce but not completely eliminate drug interference. In recent years, with the deepening of the research on CAs, many researchers at home and abroad have begun to combine the separation at the early stage with the detection steps at the later stage, and thus developed a series of efficient, highly selective, and sensitive CAs detection methods. Nikolajsen et al ^[3] [1] summarized the analysis methods of CAs in urine samples from 1988 to 2000. The analysis methods during this period were mainly based on high performance liquid chromatography (HPLC) and chemiluminescence analysis ( CL), electrochemical analysis (ECD), capillary electrophoresis (CE), and fluorescence spectrophotometry (FL) are relatively few, especially LC-MS ⁽⁴⁾ . Tsunoda et al. [2] summarized the analysis methods of CAs and their metabolites from 2000 to 2005. Parrot et al. [3] reported the detection of CAs and stimulating amino acids in rat brain by capillary electrophoresis-laser induced fluorescence method (CE-LIF). Jia Zhen et al. [4] reported the research progress of electrochemical analysis of CAs from 2000 to 2005. Dong Jie et al. [5] reviewed the characteristics of detecting CAs in tissue fluids and cells by fluorescence spectrophotometry, radiochemical method, gas chromatography (GC), high performance liquid chromatography, and electrochemical analysis.

Catecholamine adverse reactions

Ischemic necrosis of the tissue can occur, so do not let the drug leak out of the vessel. Do not overdo it to avoid acute kidney failure. In addition, a sudden drop of blood pressure may cause a drop in blood pressure. When the drug is stopped, the dose should be gradually reduced and the drip rate should be slowed down before the drug is stopped.

Catecholamine contraindications

Contraindications

Hypertension, coronary heart disease, arteriosclerosis, heart failure, hyperthyroidism, diabetes, severe renal insufficiency, patients without urine, shock patients with microcirculation disorders, elderly and pregnant women with caution!

Catecholamines Related Terms

Angiotensin	Corticotropin	insulin	Norepinephrine	Growth hormone	Prostaglandin	Renin cortisol	Epinephrine
ACTH	Aldosterone	Glucagon	Atrial natriuretic peptide	Thyroid hormone	Sex hormone	Androgens	Histamine
Cortisone	Thyroxine	Adrenocorticotropic hormone	Glucocorticoid	Antidiuretic hormone