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a catecholamine that is the neurotransmitter of most sympathetic postganglionic neurons and also of certain tracts in the central nervous system. It is also a neurohormone stored in the chromaffin granules of the adrenal medulla and released in response to sympathetic stimulation, primarily in response to hypotension. It produces vasoconstriction, an increase in heart rate, and elevation of blood pressure. It is administered intravenously in the form of the bitartrate salt as a vasopressor to restore blood pressure in certain cases of acute hypotension and to improve cardiac function during decompensation associated with congestive heart failure or cardiovascular surgery. Called also noradrenaline.
A catecholamine hormone the natural form of which is d, although the l form has some activity; the base is considered to be the postganglionic adrenergic mediator, acting on α and β receptors; it is stored in chromaffin granules in the adrenal medulla in much smaller amounts than epinephrine and secreted in response to hypotension and physical stress; in contrast to epinephrine it has little effect on bronchial smooth muscle, metabolic processes, and cardiac output, but has strong vasoconstrictive effects and is used pharmacologically as a vasopressor, primarily as the bitartrate salt.
A substance, C8H11NO3, both a hormone and neurotransmitter, that is secreted by the adrenal medulla and the nerve endings of the sympathetic nervous system and causes vasoconstriction and increases in heart rate, blood pressure, and the sugar level of the blood. Also called noradrenaline.
A catecholamine hormone, acting on α- and β-receptors; it is stored in chromaffin granules in the medulla of suprarenal gland in much smaller amounts than epinephrine and secreted in response to hypotension and physical stress; used pharmacologically as a vasopressor.
Norepinephrine is a hormone secreted by certain nerve endings of the sympathetic nervous system, and by the medulla (center) of the adrenal glands. Its primary function is to help maintain a constant blood pressure by stimulating certain blood vessels to constrict when the blood pressure falls below normal.
Catecholamine hormone with strong vasoconstrictive effects; used pharmacologically as a vasopressor, primarily as the bitartrate salt.