Introduction to dopamine

Dopamine is secreted by the brain and can affect a person's mood. Arvid Carlsson determined that the role of dopamine as the brain transmitters made him win the 2000 Nobel Prize in Medicine. Dopamine is a neurotransmitter that is used to help cells transmit pulsed chemicals. This brain endocrine is mainly responsible for the brain's lust, feeling excited and happy information transmission, but also with addiction.

In fact, love is because the relevant people and things to promote the brain to produce a large number of dopamine results. Smoking and drug addiction can increase the secretion of dopamine, so addicted to feel happy and excited. According to the study, dopamine can treat depression; and dopamine deficiency will make people lose the ability to control the muscles, the patient's hands and feet will be involuntary vibration or lead to Parkinson's disease. 2012 scientists have developed dopamine can help further treatment of Parkinson's disease. The treatment is to restore the level of dopamine in the brain and control the condition. German researchers say dopamine helps improve memory, which is found or contributes to the treatment of Alzheimer's disease.

Dopamine is most commonly used in the form of hydrochloride, white or white-like shiny crystals. Odorless, slightly bitter taste. Exposure to the air and encounter light color gradient. Soluble in water, slightly soluble in anhydrous ethanol, in chloroform or ether in the very little. Melting point 243℃-249℃ (decomposition).

Dopamine is also the brain's "reward center", also known as dopamine system.

Dopamine drug characteristics

Dopamine is a precursor of NA and is a key neurotransmitter in the hypothalamus and pituitary gland. The concentration of dopamine in the central nervous system is affected by mental factors. There are axonal associations between GnRH and dopamine in the nerve endings Interaction, and dopamine have a role in inhibiting GnRH secretion.

The brain of the neuronal material dopamine, it directly affects people's emotions. Theoretically, adding this substance will make people excited, but it will be addictive. Dopamine in the forebrain and basal ganglia appears, the basal ganglia is responsible for dealing with fear of emotions, but because of dopamine's sake, replacing the feeling of fear, so there are many people addictive, are due to dopamine.

Pharmacological toxicology of dopamine

The sympathetic nervous system adrenergic receptor and the dopamine receptors located in the kidney, mesenteric, coronary and cerebral arteries are dose-dependent. ⑴ small dose (per minute by weight 0,5-2ug / kg), mainly on the dopamine receptor, the kidney and mesenteric vasodilation, renal blood flow and glomerular filtration rate increased, urine output and sodium excretion Increase; (2) small to moderate dose (per minute by weight 2-10ug / kg), can directly stimulate the β1 receptor and indirectly promote the release of norepinephrine from the storage site, the positive stress on the heart, the myocardial contractility and Increased stroke volume, the final increase in cardiac output, systolic blood pressure, pulse pressure may increase, no change in diastolic blood pressure or a slight increase in the total resistance of the circumference often no change, coronary blood flow and oxygen consumption improved ; (3) high dose (per minute by weight greater than 10ug/kg), excited α receptor, leading to increased peripheral vascular resistance, renal vasoconstriction, renal blood flow and urine output decreased. Due to cardiac output and peripheral vascular resistance increased, resulting in increased systolic and diastolic blood pressure. ① on the heart β1 receptor agonism, increased myocardial contractility stronger; ② due to increased renal and mesenteric blood flow, to prevent the ischemia caused by these organs caused by malignant development of shock. In the same increase in myocardial contractility, the cause of arrhythmia and increased myocardial oxygen consumption is weak. In short, dopamine is associated with decreased myocardial contractility, reduced urine volume and blood volume has been particularly useful for shock patients.

The main use of dopamine

Dopamine is mainly used for all types of shock, including toxic shock, cardiogenic shock, hemorrhagic shock, central shock, especially with renal insufficiency, reduced cardiac output, peripheral vascular resistance is low and has made up blood volume Of the patients more meaningful. There are three variants of the DARPP-32 gene: TT TC CC, which determines the level of dopamine in the brain.

Dopamine adverse reactions

Dopamine adverse reactions are chest pain, difficulty breathing, palpitations, arrhythmia (especially with high doses), the body weak feeling; heart slow, headache, nausea and vomiting rare. Long-term use of large doses or small doses for patients with peripheral vascular disease, the reaction of hand, foot and hand pain or cold hands and feet; peripheral vascular contraction, may lead to local necrosis or gangrene; excessive blood pressure may occur, Drug, if necessary, to give α-blockers.

The latest study of dopamine

GDNF and Ret can act as a "switch" for toggle and regulate dopamine "recovery pump". When this "switch" failure (such as Ret knockout), the animal showed a similar expression of Vav2 knockout mice. It is generally believed that GDNF and its receptor Ret are mainly in charge of the survival of dopaminergic neurons, so their discovery extends the traditional understanding of the role of neurotrophic factor GDNF.

It is worth mentioning that the above-mentioned regulation mechanism for dopamine "recovery pump" has brain-specificity, which mainly plays a role in the brain-nucleus accumbens associated with the initiation of reward and drug addiction. For a long time, the question of whether there is a difference in the regulation mechanism of the dopamine "recovery pump" between the major dopaminergic systems in the brain is unknown. Therefore, the results of the Zhou Jiawei Study Group have revealed that the brain nucleus accumbens The significant difference in the molecular level of other major dopaminergic systems will provide an important theoretical basis for understanding and regulating the formation of drug addiction. Indeed, in this study, they found that the dopamine "recovery pump" mechanism disorder caused by the deletion of the Vav2 gene can effectively inhibit the formation of cocaine-induced drug addiction, suggesting that as a new signal transduction pathway, GDNF / Ret / Vav2 Signaling pathway plays a potentially important role in the treatment of cocaine addiction.