Related Experiment Video
Updated: Aug 10, 2026

Fractionation for Resolution of Soluble and Insoluble Huntingtin Species
Published on: February 27, 2018
Blood monoamine metabolism in Huntington's disease
Abstract:
In 25 patients with Huntington's disease (HD), the mean blood concentration of serotonin (5-HT) and percentage of plasma free tryptophan were significantly increased while plasma concentrations of total and protein-bound tryptophan were significantly decreased. The pattern of changes in tryptophan concentrations was related to clinical severity but not to 5-HT levels. Platelet monoamine oxidase (MAO) activity was significantly increased in patients with HD; kinetic and marker enzyme studies suggested an increased enzyme concentration. Offspring at risk for HD also had elevated platelet MAO activity but normal concentrations of blood 5-HT and plasma tryptophan. In ten patients, plasma epinephrine concentrations were significantly increased; plasma dopamine and norepinephrine concentrations were positively related to MAO activity. The finding of peripheral neurotransmitter abnormalities in HD raises the question of an interaction between CNS and peripheral processes or a systemic disorder of neurotransmitter metabolism.
Related Concept Videos
Drugs Affecting Neurotransmitter Release or Uptake
Drugs Affecting Neurotransmitter Synthesis
Parkinson's Disease: Treatment
Parkinson's Disease is primarily a result of the loss of dopaminergic neurons in the substantia nigra pars compacta. The cornerstone of its...
Nonlinear Pharmacokinetics: Dependence of Elimination Half-Life and Dose Clearance
A study on guinea pigs examined the...
Parkinson Disease ll: Pathophysiology
Huntington Disease l: Introduction

