Search results
Results from the WOW.Com Content Network
Two catecholamines, norepinephrine and dopamine, act as neuromodulators in the central nervous system and as hormones in the blood circulation. The catecholamine norepinephrine is a neuromodulator of the peripheral sympathetic nervous system but is also present in the blood (mostly through "spillover" from the synapses of the sympathetic system).
l-DOPA can be directly metabolized by catechol-O-methyl transferase to 3-O-methyldopa, and then further to vanillactic acid. This metabolic pathway is nonexistent in the healthy body, but becomes important after peripheral l-DOPA administration in patients with Parkinson's disease or in the rare cases of patients with AADC enzyme deficiency. [11]
Neuromelanin is an autoxidation byproduct of catecholamines, and it has been suggested that catecholaminergic neurons surrounded by a low density of glutathione peroxidase cells are more susceptible to degeneration in Parkinson's disease than those protected against oxidative stress.
For premium support please call: 800-290-4726 more ways to reach us
Catecholaminergic means "related to catecholamines". The catecholamine neurotransmitters include dopamine , epinephrine (adrenaline), and norepinephrine (noradrenaline). A catecholaminergic agent (or drug ) is a chemical which functions to directly modulate the catecholamine systems in the body or brain.
The mechanisms of sympathomimetic drugs can be direct-acting (direct interaction between drug and receptor), such as α-adrenergic agonists, β-adrenergic agonists, and dopaminergic agonists; or indirect-acting (interaction not between drug and receptor), such as MAOIs, COMT inhibitors, release stimulants, and reuptake inhibitors that increase the levels of endogenous catecholamines.
An adrenergic storm is a sudden and dramatic increase in serum levels of the catecholamines adrenaline and noradrenaline (also known as epinephrine and norepinephrine respectively), with a less significant increase in dopamine transmission.
However, when catecholamines active the beta receptor, the blood vessel dilates (gets larger) and allows for increased blood flow, reducing the blood pressure. [117] If a pheochromocytoma patient is only started on a beta-adrenoceptor antagonist, this reverses the protective vasodilation and worsens the patient's hypertension.