CATECHOLAMINES

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CATECHOLAMINES DEFINITION: * These are the compounds that possess a catechol moiety that has a benzene ring with 2 hydroxyl groups lying side by side and also an amine side chain . * Catecholamines are the "fight-or-flight" hormones that are released by adrenal glands in response to stress conditions. * They are a part of the sympathetic nervous system. The important catecholamines used pharmacologically are 1.NORADRENALINE:this is also called as norepinephrine.it is a transmitter released by the sympathetic nerve terminals. 2.ADRENALINE:this is also called as epinephrine.it is an adrenal medulla secreting hormone. 3.DOPAMINE:it is the precursor of adrenaline and noradrenaline metabolism.it is a neurotransmitter of CNS. 4.ISOPROTERENOL:It is a synthetic derivative of noradrenaline. FUNCTIONS OF CATECHOLAMINES: * Two of the catecholamines, norepinephrine and dopamine, acts as neuromodulators in central nervous system and as hormones in the blood circulation process. * The norepinephrine is a neuro modulator of peripheral sympathetic nervous system but it is also present in blood . * High catecholamine levels in blood are due to stress, which can be induced from the psychological reactions or environmental stressors like high sound levels, intense light, or low blood sugar levels in the body. * Extremely large levels of catecholamines (termed as catecholamine toxicity) may occur in central nervous system trauma as a result of stimulation or damage of the nuclei in brainstem. * In emergency medicine, this happening is widely known as catecholamine dump. * Extremely high levels of catecholamine can also be caused by neuroendocrine tumors in the adrenal medulla, a treatable condition known as pheochromocytoma. * High levels of catecholamines may be caused by deficiency of monoamine oxidase A . * This is one of the enzyme that is responsible for the degradation of these type of neurotransmitters and thus elevates the bioavailability of them considerably. Effects * Catecholamines generally cause physiological changes that make the body for physical activity (i.e.,fight-or-flight response). * Some typical effects are i ncrease in heart rate, blood pressure, blood glucose levels, and a general reaction of the sympathetic nervous system. * Some drugs, for instance tolcapone (which is a central COMT-inhibitor), increases the levels of all catecholamines. DEGRADATION: * THE half-life OF CATECHOLAMINES IS a few minutes during the blood circulation. * They may be degraded either by methylation bycatechol-O-methyltransferases or by deamination by monoamine oxidases (MAO). * Amphetamines and MAOIs bind to Mono Amino Oxidase to inhibit its action of breaking down the catecholamines. * This is the major reason why the effects of amphetamines possess a longer lifespan cocaine and other substances. * Amphetamines also suppresses re-absorption. references: RANG AND DALE'S PHARMACOLOGY 6TH EDITION,PAGE NO:168-174. "THIS BLOG DOES NOT CONTAIN ANY PLAGIARISED MATERIAL" PHARMA WARRIORS
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K Rajakrishna's picture

Both adrenaline and noradrenaline are not called as epinephrine. Please check.
Sandhya Sravya malla's picture

thank you and it was a flaw made due to over look.anyways thank you pharmawarriors

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