|
|
||||||||
Article |
Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
Abstract
Abstract I. Introduction II. Facts and Fallacies A. Catecholamine Deamination B. Formation of Vanillylmandelic Acid C. Contribution of Vesicular Leakage to Catecholamine Metabolism D. Neuronal and Extraneuronal Catecholamine Metabolism E. Central and Peripheral Contributions to Norepinephrine Metabolism F. Central and Peripheral Contributions to Dopamine Metabolism III. Clinical Implications A. Neurodegenerative Processes B. Neurocirculatory Physiology and Pathophysiology C. Catecholamine-Producing Tumors IV. Future Perspectives
This article provides an update about catecholamine metabolism, with emphasis on correcting common misconceptions relevant to catecholamine systems in health and disease. Importantly, most metabolism of catecholamines takes place within the same cells where the amines are synthesized. This mainly occurs secondary to leakage of catecholamines from vesicular stores into the cytoplasm. These stores exist in a highly dynamic equilibrium, with passive outward leakage counterbalanced by inward active transport controlled by vesicular monoamine transporters. In catecholaminergic neurons, the presence of monoamine oxidase leads to formation of reactive catecholaldehydes. Production of these toxic aldehydes depends on the dynamics of vesicular-axoplasmic monoamine exchange and enzyme-catalyzed conversion to nontoxic acids or alcohols. In sympathetic nerves, the aldehyde produced from norepinephrine is converted to 3,4-dihydroxyphenylglycol, not 3,4-dihydroxymandelic acid. Subsequent extraneuronal O-methylation consequently leads to production of 3-methoxy-4-hydroxyphenylglycol, not vanillylmandelic acid. Vanillylmandelic acid is instead formed in the liver by oxidation of 3-methoxy-4-hydroxyphenylglycol catalyzed by alcohol and aldehyde dehydrogenases. Compared to intraneuronal deamination, extraneuronal O-methylation of norepinephrine and epinephrine to metanephrines represent minor pathways of metabolism. The single largest source of metanephrines is the adrenal medulla. Similarly, pheochromocytoma tumor cells produce large amounts of metanephrines from catecholamines leaking from stores. Thus, these metabolites are particularly useful for detecting pheochromocytomas. The large contribution of intraneuronal deamination to catecholamine turnover, and dependence of this on the vesicular-axoplasmic monoamine exchange process, helps explain how synthesis, release, metabolism, turnover, and stores of catecholamines are regulated in a coordinated fashion during stress and in disease states.
This article has been cited by other articles:
![]() |
M. Dematteis, C. Julien, C. Guillermet, N. Sturm, S. Lantuejoul, M. Mallaret, P. Levy, and E. Gozal Intermittent Hypoxia Induces Early Functional Cardiovascular Remodeling in Mice Am. J. Respir. Crit. Care Med., January 15, 2008; 177(2): 227 - 235. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Chen, Y. Ding, B. Cagniard, A. D. Van Laar, A. Mortimer, W. Chi, T. G. Hastings, U. J. Kang, and X. Zhuang Unregulated Cytosolic Dopamine Causes Neurodegeneration Associated with Oxidative Stress in Mice J. Neurosci., January 9, 2008; 28(2): 425 - 433. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Pacak Preoperative Management of the Pheochromocytoma Patient J. Clin. Endocrinol. Metab., November 1, 2007; 92(11): 4069 - 4079. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. J. Singh and G. Eisenhofer High-Throughput, Automated, and Accurate Biochemical Screening for Pheochromocytoma: Are We There Yet? Clin. Chem., September 1, 2007; 53(9): 1565 - 1567. [Full Text] [PDF] |
||||
![]() |
A. Sainsbury, S. Lin, K. McNamara, K. Slack, R. Enriquez, N. J. Lee, D. Boey, G. A. Smythe, C. Schwarzer, P. Baldock, et al. Dynorphin Knockout Reduces Fat Mass and Increases Weight Loss during Fasting in Mice Mol. Endocrinol., July 1, 2007; 21(7): 1722 - 1735. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Marchitti, R. A. Deitrich, and V. Vasiliou Neurotoxicity and Metabolism of the Catecholamine-Derived 3,4-Dihydroxyphenylacetaldehyde and 3,4-Dihydroxyphenylglycolaldehyde: The Role of Aldehyde Dehydrogenase Pharmacol. Rev., June 1, 2007; 59(2): 125 - 150. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. N. Andrews, A. E. Bharucha, M. Camilleri, P. A. Low, B. Seide, D. Burton, K. Baxter, and A. R. Zinsmeister Nitrergic contribution to gastric relaxation induced by glucagon-like peptide-1 (GLP-1) in healthy adults Am J Physiol Gastrointest Liver Physiol, May 1, 2007; 292(5): G1359 - G1365. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. M MANGER An overview of pheochromocytoma: history, current concepts, vagaries, and diagnostic challenges. Ann. N.Y. Acad. Sci., August 1, 2006; 1073: 1 - 20. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Qvisth, E. Hagstrom-Toft, S. Enoksson, E. Moberg, P. Arner, and J. Bolinder Human Skeletal Muscle Lipolysis Is More Responsive to Epinephrine Than to Norepinephrine Stimulation in Vivo J. Clin. Endocrinol. Metab., February 1, 2006; 91(2): 665 - 670. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. E. Cryer Mechanisms of Hypoglycemia-Associated Autonomic Failure and Its Component Syndromes in Diabetes Diabetes, December 1, 2005; 54(12): 3592 - 3601. [Abstract] [Full Text] [PDF] |
||||
![]() |
November 22 Highlight and Commentary: Is time of the essence? The continuing search for a noninvasive measure of sympathetic adrenergic function Neurology, November 22, 2005; 65(10): 1517 - 1517. [Full Text] [PDF] |
||||
![]() |
T. Kim, C.-f. Zhang, Z. Sun, H. Wu, and Y. P. Loh Chromogranin A Deficiency in Transgenic Mice Leads to Aberrant Chromaffin Granule Biogenesis J. Neurosci., July 27, 2005; 25(30): 6958 - 6961. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Valette, M. Bottlaender, F. Dolle, C. Coulon, M. Ottaviani, and A. Syrota Acute Inhibition of Cardiac Monoamine Oxidase A after Tobacco Smoke Inhalation: Validation Study of [11C]Befloxatone in Rats Followed by a Positron Emission Tomography Application in Baboons J. Pharmacol. Exp. Ther., July 1, 2005; 314(1): 431 - 436. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. S. Goldstein, B. Eldadah, C. Holmes, S. Pechnik, J. Moak, and Y. Sharabi Neurocirculatory Abnormalities in Chronic Orthostatic Intolerance Circulation, February 22, 2005; 111(7): 839 - 845. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |