title: Neurotransmitters excreted in the urine as biomarkers of nervous system activity: validity and clinical applicability.
abstract: Strategies for managing the nervous system are numerous while methods of evaluating the nervous system are limited. Given the physiological importance of neurotransmitters as signaling molecules in the nervous system, the measurement of neurotransmitters has significant potential as a clinical tool. Of all the biological fluids that can be utilized, urinary neurotransmitter testing, due to its stability, sensitivity, and non-invasiveness, is the desired method to analyze nervous system function. Increasing use of this technology in a clinical setting demands a review of its feasibility, utility, and clinical value. We review the current body of literature pertaining to the mechanism of neurotransmitter transport across the blood-brain barrier as well as neurotransmitter filtration and excretion by the kidneys. In addition, this review summarizes the historical use of urinary neurotransmitter assessment to diagnose pheochromocytoma. Early research also correlated urinary assessment of neurotransmitters to various clinical symptoms and treatments of which we present research only for depression, ADHD, and inflammation because of the abundant amount of research in these areas. Finally, we review the limitations and challenges of urinary neurotransmitter testing. Taken together, evidence suggests that neurotransmitters excreted in the urine may have a place in clinical practice as a biomarker of nervous system function to effectively assess disturbances and monitor treatment efficacy.
authors.affiliation: NeuroScience, Inc. 373 280th Street, Osceola, WI 54020, USA. david.marc@neurorelief.com
authors.forename: David T
authors.initials: DT
authors.lastname: Marc
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Ailts
authors.forename: Danielle C Ailts
authors.initials: DC
authors.lastname: Campeau
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bull
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Olson
mesh_terms: D000818:Animals; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000652:urine; D001692:Biological Transport / Q000502:physiology; D015415:Biomarkers / Q000652:urine; D001812:Blood-Brain Barrier / Q000378:metabolism; D003866:Depressive Disorder / Q000175:diagnosis / Q000652:urine; D006801:Humans; D007249:Inflammation / Q000175:diagnosis / Q000652:urine; D009420:Nervous System / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000652:urine*; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; D018377:Neurotransmitter Agents