Norepinephrine, occurrence

Tyrosine (Tyr or Y) (4-hydroxyphenylalanine ((5)-2-amino-3-(4-hydroxyphenyl)-propanoic acid)) is a polar, neutral, aromatic amino acid with the formula H00CCH(NH2)CH2C6H50H and is the precursor of thyroxin, dopamine, norepinephrine (noradrenaline), epinephrine (adrenaline), and the pigment melanin. Being the precursor amino acid for the thyroid gland hormone thyroxin, a defect in this may result in hypothyroidism. Tyr is extremely soluble in water, a property that has proven useful in isolating this amino acid from protein hydrolysates. The occurrence of tyrosine- 0-sulfate as a constituent of human urine and fibrinogen has been reported. ... 

Tramadol has about one tenth the pain-relieving ability of morphine.53 There are two enantiomers, and both contribute to pain relief, but via different mechanisms. (+)-Tramadol and the metabolite (+)-0-desmethy 1-tramadol, which is referred to as Ml, are agonists of the mu opioid receptor. (+)-Tramadol inhibits serotonin reuptake and (-)-tramadol inhibits norepinephrine re uptake.25 This latter action enhances the inhibitory effects on pain transmission in the spinal cord. Because the actions of the two enantiomers are complementary, they are usually supplied as a racemic mixture. However, because it is a serotonin-reuptake blocker, interaction with other medications can lead to the occurrence of serotonin syndrome.54... 

Hormone synthesis and release can be initiated by both extrinsic and intrinsic factors.2 Extrinsic factors include various environmental stimuli such as pain, temperature, light, and smell. Intrinsic stimuli include various humoral and neural factors. For instance, release of a hormone can be initiated by other hormones. These occurrences are particularly typical of the anterior pituitary hormones, which are controlled by releasing hormones from the hypothalamus. Hormonal release can be influenced by neural input a primary example is the sympathetic neural control of epinephrine and norepinephrine release from the adrenal medulla. Other intrinsic factors that affect hormone release are the levels of ions and metabolites within the body. For instance, parathyroid hormone release is governed directly by the calcium concentration in the bloodstream, and the release of... 

Cardiovascular Effects. Thyroid hormones appear to increase heart rate and myocardial contractility, thus leading to an increase in cardiac output. It is unclear, however, if this occurrence is a direct effect of these hormones or if the thyroid hormones increase myocardial sensitivity to other hormones (norepinephrine and epinephrine). 

Ephedrine and pseudoephedrine share properties with cocaine and with the amphetamines because they (1) stimulate (3-receptors directly, and (2) also cause the increased release of norepinephrine. Chronic exposure to abnormally high levels of circulating catecholamines can damage the heart. This is certainly the case with cocaine and methamphetamine (116,117), but ephedrine-related cardiomyopathy is an extremely rare occurrence, occurring only in individuals who take massive amounts of drug for prolonged periods of time. Only two papers have ever been published on the subject (118,119). 

Norepinephrine (201) was a reasonably efficient precursor for normacromerine which indicates that )S-hydroxylation can be an early step, whilst the occurrence of synephrine (198) in C. macromeris indicates that N-methylation can likewise occur early. 

Neuroblastoma 96 Neurocirculatory disturbance 124 Noradrenaline (norepinephrine, arterenol) excretion 10, 11 human brain 57 ff kidney function 72, 74, 80 localization 4, 10 metabolism 15, 16 microcirculation 80, 81, 86 occurrence 30 If Parkinson s disease 62 pharmacology 65 production 3,7 respiratory metabolism 87, 90 turnover 24, 25 Noradrenochrome 21 Normetanephrine (= 3-O-methylnoradrena-line) 11, 15, 34, 66 Norsynephrine see /7-Octopamine... 

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