L-thyroxine treatment and neurotransmitter levels in the cerebrospinal fluid of hypothyroid patients: a pilot study

Abstract

Monoamine precursors, neurotransmitters and their metabolites were studied in cerebrospinal fluid (CSF) obtained from nine newly diagnosed hypothyroid patients.Before treatment, the serum TSH correlated positively with the CSF concentrations of tyrosine and phenylalanine.During treatment, the levels of the precursors tryptophan, phenylalanine and tyrosine decreased significantly, as was also the case with dopamine and the noradrenaline metabolite 4-hydroxy-3-methoxyphenylglycol (HMPG), but not with serotonin, noradrenaline and the serotonin metabolite 5-hydroxyindoleacetic acid, nor the dopamine metabolites homovanilic acid and dihydroxyphenylacetic acid. The study provided some indication that the CSF levels of phenylalanine and tyrosine are related to thyroid function. Furthermore, we have found an indication that L-thyroxine treatment affects the CSF levels of the precursors as well as dopamine and HMPG. Our results support the notion that there is an interaction between thyroid function and CSF disposition of monoamine compounds.

Depressive Symptoms in Hypothyroid Disorder with some Observations on Biochemical Correlates

“…The CSF was immediately protected from light, centrifuged, and stored at -70°C until analyzed. For details regarding the analyses, see Sjöberg et al [21] and Gunnarsson et al [27].…”

“…We have previously reported CSF data on monoamine compounds [21] and CCK peptides [22] in these patients, before and during L-thyroxine treatment.…”

Platelet Serotonin Concentration and Monoamine Oxidase Activity in Hypothyroid Patients

“…Augmentation therapy with T 3 or T 4 to different antidepressants induced remission in treatment-resistant depressed patients [13]. In hypothyroid female patients, treatment with T 4 induced a significant decrease in pretreatment values of 5-HT and catecholamine precursor in cerebrospinal fluid [14]. A significant decrease in D -fenfluramine-induced cortisol response was also found in hypothyroid patients [15], probably due to a decrease in 5-HT2A receptor sensitivity [16].…”

Season of birth in suicidology: Neurobiological and epidemiological studies

“…Although most studies with CSF have measured the metabolites of monoamines, some studies also measure the CSF levels of the transmitters serotonin, dopamine and noreprinephrine themselves, and of their precursors tryptophan, tyrosine and Phenylalanin (Eklundh et al, 1996;Sjöberg et al, 1998). This is interesting, since CSF is becoming increasingly appreciated as an important physiological channel for "volume transmission" (Zoli et al, 1998), which consists of three-dimensional diffusion of signals in the extracellular fluid for distances larger than the synaptic cleft.…”