The metabolism of phenol amines in children.

nameCatecholamines refers to amines that contain the basic structure of phthalates. Bioactive pacrysamines in the body include dopamine (dopamine, DA), norepinephrine (norepinephrine, noradrenaline, NE) and epinephrine (epinephrine, adrenalin, E). Their structure is as follows.and epinephrine are both
hormones
secreted by adrenal myelin and neurotransmitter of epinephrine-energy fibers in the communication and central nervous system. NE is widely distributed within the hub, with more content and less E, so we focus on ne metabolism. DA is mainly concentrated in the cone outer system, is also a neurotransmitter.(i) Biosynthesis of cerium phenolamine neural
tissue
the synthetic raw material of cerium phenolamine comes from tyrosine in the blood, and its synthesis process.In the above-mentioned process, the first step is tyrosine hydroxylase participation, it is located in the cytoplasma of the epinephrine
energy nerve fiber, the content is small, low
activity, become the NE-generated speed limit enzyme, tethydrogen biothhotrexate is its coenzyme, O2 and Fe
is also an essential factor in synthesis; The specificity of this enzyme is not high, and the general amino acid dehydrase, requires acetaldehyde phosphate as a coenzyme, the third step is dopamine hydroxyase catalyzed oxidation reaction, oxidation occurs on β carbon atoms, this enzyme does not exist in the cytoplasm but attached to the vesicle wall, belongs to the
protein
containing Cu, and needs
vitamin
C as an auxiliary factor.From the subcellular horizontal distribution of the above enzymes can be understood, the final step of synthesis of NE can only be carried out in the vesicles, NE synthesis is not only regulated by the speed limit of tyrosine hydroxygenase, but also when the concentration of free NE in the nerve ending plasma is too high, but also due to feedback inhibition of the role of tyrosine hydroxylase to reduce the synthesis of NE.benzene ethanolamine-N-methyl
-transferase
is mainly found in adrenal myelin cells, which enable NE methylation to produce epinephrine. Although this enzyme is present in a small amount in the brain, it is generally believed that the adrenaline content in the lactating brain is very low. It has been suggested that if phenylamphetamine N methyl transferase activity is too high, dopamine can be directly turned into N methyl dopamine and other things, resulting in metabolic disorders of these metabolic substances, which may be one of the reasons for schizophrenia.(ii) dethyroidized epinephrine (NE) 1. Store and release NE in place after synthesis in the vesicle. It is loosely combined with ATP, chromium-thromium particle protein, etc., so that NE is not easily penetrated into the plasma and is destroyed by monoamine
oxidase
protein. When nerve impulses reach the end, the follicles near the synaptic frontal membrane fuse with the frontal membrane, breaking and ingling. The NE in the vesicle is then released into the synapse gap along with chromium particle proteins, etc.. 2. Where NE is released into the synapse gap ne can bind to the NE subject on the synapse post-membrane to produce physiological effects. Then, about three-quarters of NE is re-ingested by the synaptic prefilm. NE after ingestion of cytos paste can also enter the bubble storage. Re-ingestion is an energy-consuming process associated with the Na-, K-ATP enzyme system on the synaptic prefilm and the Mg-ATP enzyme system on the vesicle membrane.
other part of NE is ingested by the afterdural membrane, where it is decomposed and inactivate. Others are destroyed or escaped into the bloodstream during synapses. With the exception of NE re-ingested by synaptic prefilms and vesicles for reuse, most of the rest of NE is inactivate by enzyme-promoted degradation.
NE's enzyme-promoting degradation, as shown in Figure 14, monoamine oxidase (MAO) and catecholotransmethylase (COMT) are the two main enzymes that catalyz the breakdown of catalytic catalytic phenol amines, which are not only present in nerve tissue, but are also widely distributed in non-neural tissues, and there are many mitochondrial membranes of neurons.
NE is affected by MAO, first oxidizing deaminoformide to produce aldehyde, which in turn becomes alcohol or acid. 3-methoxy-4-hydroxybenzene glycol (MHPG) is the main degradation product of NE in the hub. In the outer weeks, oxidized into vanilla-based tonsil acid (VMA) mainly. NE (mainly hormones) in the blood circulation is excreted when tissues such as the liver and kidneys are turned into methoxygen metabolites by COMT.
Now, clinically often determine the content of VMA in the urine, as an indicator of understanding the function of the sensory nerves, when suffering from chromosoma and neuroblastoma, because the tumor tissue also produces NE or E, its metabolite VMA correspondingly increased, so it is quite meaningful in diagnosis.neurocytosomes in the central nervous system are concentrated in the yan and bridge brains, and their path paths have been studied clearly. But whether NE is inhibitory or excitable in the hub is not yet certain and may vary from site to site. The physiological effects of NE are also difficult to express in the simple terms "excitement" and "inhibition".
some animal experiments have observed that NE can cause animal drowsiness, hypothermia, and eating behavior. Some people think that reduced NE in the brain can show depression; In summary, the function of NE in the brain may be closely related to the regulation of body temperature, eating behavior, analgesics, cardiovascular system and mental state.(iii) dopamine (DA) Dopamine is a precursor to epinephrine in the biosynthesis process of the phenol amine-type delivery. Where there is NE tissue in the body, there must also be a DA. Because DA is highly concentrationed in certain parts of the hub and its distribution is not parallel to NE, it is generally considered to be an independent neurotransmitter in itself. role of dopamine in the brain is multi-ion, it may be related to the strengthening of body motor function, the strengthening of pituitary
endocrine
function and the regulation of mental activity. the follicles in the nerve endings of dopamine are the place to store the DA. This type of cyst is different from NE follicles, which do not contain dopamine β serotonin, so daxy is not hydroxy into NE. In addition, in epinephrine fibers, NE vesicles are required for storage β there is hydroxyl in the location, while there is no hydroxyl in the β da structure.
the storage, release and enzymatic degradation of the DA are very similar to NE, while the update speed is faster than NE. The metabolites of THEA in the brain are mainly 3-methoxy-4-hydroxybenzene acetic acid (homovanic acid short-form HVA, a.k.a. herbic acid

).