Amine Metabolites In Cerebrospinal Fluid Research Articles

Cerebrospinal Fluid Biogenic Monoamine Analysis for Diagnosis of Primary Neurotransmitter Disorders.

Biogenic amine neurotransmitters metabolism is a multistep pathway with pterin and pyridoxal phosphate (vitamin B6) as cofactors. A defect in biogenic amine and cofactor metabolism and vesicular transporters result in a primary neurotransmitter disorders. These are a well-recognized groups of inherited disorders and often present with features overlapping with other neurological conditions. Their diagnosis is made by analysis of biogenic amine metabolites in cerebrospinal fluid (CSF) and other body fluids and respective enzyme assays. Many of these disorders are treatable and deficits can be reverted by timely intervention. CSF biogenic amine or cofactor metabolite analysis is one of the primary indicators of a neurotransmitter disorder. In this paper, 3 cases are reported-2 of cofactor deficiency and 1 with enzyme deficiency wherein biogenic amine estimation has assisted in diagnosis.

Obituary of Theodore L. Sourkes, PhD, FRSC, OC.

Obituary of Theodore L. Sourkes, PhD, FRSC, OC.

Age and Gender-Related Changes in Biogenic Amine Metabolites in Cerebrospinal Fluid in Children.

Metabolites of cerebrospinal biogenic amines (dopamine and serotonin)are an important tool in clinical research and diagnosis of children with neurotransmitter disorders. In this article we focused on finding relationships between the concentration of biogenic amine metabolites, age, and gender. We analyzed 148 samples from children with drug resistant seizures of unknown etiology and children with mild stable encephalopathy aged 0-18 years. A normal profile of biogenic amineswas found in 107 children and those children were enrolled to the study group. The CSF samples were analyzed by HPLC with an electrochemical detector. The concentrations of the dopamine and serotonin metabolites homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA), respectively, were high at birth, gradually decreasing afterward until the 18 years of age. Nevertheless, the HVA/5-HIAA ratio did not vary with age, except in the children below 1 year of age. In the youngest group we observed a strong relationship between the HVA/5-HIAA ratio and age (r = 0.69, p < 0.001). There were no statistical differences in the level of both dopamine and serotonin metabolites between boys and girls, although a tread toward lower HVA and 5-HIAA in the boys was noticeable. Significant inter-gender differences in the level of HVA and 5-HIAA were noted only in the age-group of 1-4 years, with 5-HIAA being higher in the girls than boys (p = 0.004). In conclusion, the study revealed that the concentration of biogenic amine metabolites is age and sex dependent.

Biogenic amine metabolism in juvenile neurocardiogenic syncope with dysautonomia.

ObjectiveBiogenic amine brain levels and their cerebral metabolism are frequently studied by quantitation of biogenic amine metabolites in cerebrospinal fluid (CSF) compared to age-matched controls. There is a paucity of studies in adolescents and young adults investigating the potential role of disordered cerebral biogenic amine metabolism in young patients who have dysautonomia based on abnormal head-up tilt table (HUTT).MethodsIn a cohort of juvenile patients with neurocardiogenic syncope and dysautonomia documented by abnormal HUTT, biogenic amine metabolites of dopamine and serotonin were quantitated in 18 patients (15 females). HUTT testing is an effective clinical method to evaluate posturally induced physiological events in patients suspected of neurocardiogenic syncope with dysautonomia.ResultsLevels of the dopamine metabolite (homovanillic acid: HVA) and/or the serotonin metabolite (5-hydroxyindoleacetic acid: 5HIAA) were significantly reduced in 13 patients compared to age-matched controls.InterpretationPeripheral biogenic amines and their metabolites have been extensively studied in adults with dysautonomia due to various neurodegenerative disorders (Parkinson disease, multiple system atrophy, primary autonomic failure). Our findings indicate that more than two-thirds of this cohort of young patients with dysautonomia of variable severity have a defect in cerebral biogenic amines, particularly in dopamine and serotonin metabolism.

Abnormalities of biogenic amines affecting the metabolism of serotonin and catecholamines.

This paper describes the relevance of measuring biogenic amine metabolites in cerebrospinal fluid in order to detect inborn errors affecting catecholamines and serotonin biosynthesis. Defects in tetrahydrobiopterin and a deficiency of aromatic L-amino acid decarboxylase, tyrosine hydroxylase or dopamine-beta-hydroxylase are candidate inborn errors for neurotransmitter metabolites screening. This investigation has to be considered in any child with motor retardation and extrapyramidal signs.

Attempted suicide characteristics and cerebrospinal fluid amine metabolites in depressed inpatients

Serotonin abnormalities have been reported in the brain of suicide victims. Evidence of a serotonin deficiency in suicide attempters is less consistent. We hypothesized that a serotonin deficiency may be present in suicide attempters whose attempt behavior more closely approximates completed suicide. Sixty-seven (67) drug-free depressed inpatients (46 suicide attempters, 21 nonattempters) underwent research clinical assessments and a lumbar puncture. Cerebrospinal fluid (CSF) monoamine metabolites were assayed. Degree of medical damage and intent of the most recent suicide attempt were rated. CSF amine metabolites did not differentiate suicide attempters as a group from nonattempters. However, reduced serotonergic activity, as indicated by lower levels of CSF-5-hydroxyindoleacetic acid (5-HIAA) was associated with a history of planned suicide attempts and with suicide attempts that resulted in greater medical damage. Other monoamine metabolites did not correlate with seriousness of suicidal behavior, except for low CSF homovanillic acid and higher medical damage. No correlation was found with violent method. Planned and more medically damaging suicide attempts appear to be associated specifically with low serotonergic activity and, therefore, resemble completed suicide both behaviorally and biochemically. It remains to be determined whether low levels of CSF 5-HIAA can predict greater medical damage in future suicide attempts.

Elevated Biopterin and Homovanillic Acid Levels in Cerebrospinal Fluid From Children With Aseptic Meningitis

To examine biopterin fractions and biogenic amine metabolites in cerebrospinal fluid in aseptic meningitis, the concentrations of homovanillic acid, 5-hydroxyindoleacetic acid, and the total, the oxidized form, and the reduced form of biopterin were determined in cerebrospinal fluid specimens from 15 children with aseptic meningitis in the acute phase, 15 children with aseptic meningitis in the recovery phase, and six other children as controls. The concentration of each substance was significantly higher in the acute phase than in the recovery phase. Homovanillic acid in the acute phase was significantly increased compared to that in the control group. The concentrations of the total, the oxidized form, and the reduced form of biopterin, and 5-hydroxyindoleacetic acid were higher in the acute phase than those in the controls; however, the differences were not significant. The concentration of each substance in the recovery phase was not significantly different from that in the controls. There was no difference in the 5-hydroxyindoleacetic acid/homovanillic acid ratio or in the reduced form/total biopterin ratio among the patients in acute and recovery phases and the controls. These results suggested that levels of biopterin and biogenic amine metabolites in cerebrospinal fluid are increased in the acute phase of aseptic meningitis and return to normal during the recovery phase. This is the first report of increased concentrations of biopterin fractions and biogenic amine metabolites in aseptic meningitis.

Biogenic amine metabolites in the CSF of patients with late onset and alcoholic ataxias

The levels of monoamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3-methoxy-4-hydroxyphenylglycol (MHPG) and 5-hydroxyindoleacetic acid (5-HIAA) were measured in lumbar cerebrospinal fluid (CSF) from 10 patients with late onset ataxia, 8 patients with alcoholic ataxia and 18 control patients. The levels did not differ significantly among the three groups of patients suggesting that the central neuronal systems utilizing dopamine, noradrenaline and 5-hydroxytryptamine do not have a significant pathophysiological role in these forms of ataxias. The measurement of CSF amine metabolites probably does not contribute to the differential diagnosis of ataxias.

CSF and urine biogenic amine metabolites in Rett syndrome

The metabolites of dopamine (homovanillic acid-HVA), noradrenaline (4-hydroxy-3-methoxy-phenylglycol-HMPG), and serotonin (5-hydroxyindoleacetic acid-5-HIAA) were measured in cerebrospinal fluid (CSF) from 38 patients and urine from 36 patients with typical Rett syndrome (RS) and compared with controls of similar age. CSF metabolite concentrations were the same in the patients and controls. Urinary metabolites expressed per mol creatinine were significantly higher in older RS patients. This difference is partly explained by lower urinary creatinine levels in older RS patients, due to their known reduction in muscle mass. Alterations in CSF or urine biogenic amine metabolite concentrations do not appear to represent the primary abnormality in RS, and their measurement cannot be regarded as a reliable means of diagnosis.

A Variant of Akinetic Mutism: Biochemical and Physiological Studies During Successful Withdrawal from Sinemet

A patient with a variant of akinetic mutism had responded to Sinemet and had been maintained at a functional level on this medication. We report follow-up studies of his speech and language skills, blink rate, and cerebrospinal fluid amine metabolites while on Sinemet and following its withdrawal. On Sinemet, cerebrospinal dopamine metabolites were normal at 90 min postdose. Off Sinemet, the patient experienced no clinical deterioration and some improvement in his speech and language skills. Although the cerebrospinal dopamine metabolites fell to markedly subnormal levels, his blink rate remained abnormally high (85-100/min) for 5 weeks. An antibody to dopaminergic neurons was present in the cerebrospinal fluid. The data suggest that the patient had sustained damage to the substantia nigra, with a resultant deficit in endogenous dopamine production. Remodeling appears to have occurred in the striatal system despite Sinemet-induced normal levels of dopamine available for release by striatal neurons. Key Wo...

Plasma and urine catecholamines and cerebrospinal fluid amine metabolites as hypothermia markers in guinea-pigs.

Changes in catecholamines (CA) in the plasma and urine and metabolites of CA and serotonin (5-HT) in the cerebrospinal fluid of guinea-pigs in hypothermia (Trec 30 degrees C) and after subsequent rewarming were determined with HPLC in order to obtain data on early stress reactions and their timing. Both noradrenaline (NA) and adrenaline (A) were low in the plasma but high in the urine after the hypothermic period. These had normalized in the plasma after rewarming but were still high in the urine. Dopamine values tended to be low (not significant). Methoxyhydroxyphenylglycol and homovanilic acid were elevated in the cerebrospinal fluid both after hypothermia and following rewarming, and 5-hydroxyindoleacetic acid after rewarming. The ratio of adrenaline to noradrenaline, the catecholamine hypothermia index, in the urine had risen 24-fold after hypothermia and 40-fold after rewarming. The results support the view that elevated catecholamine concentrations in the urine and elevated values of their metabolites in the cerebrospinal fluid could be regarded as hypothermia markers. However, other stress conditions, which have lasted at least a few hours, should be excluded in the final interpretation.

Selected ion monitoring analysis of monoamine metabolites in cerebrospinal fluid. Application to the study of in vivo effects of alpha 2-antagonists.

The technique of isotope dilution mass spectrometry has been used for the measurement of biogenic amine metabolites in cerebrospinal fluid (CSF). CSF samples were collected from rabbits treated with alpha 2-antagonists. The aim of our study was to determine the specificity of these drugs on the central nervous noradrenergic, dopaminergic and serotonergic activity as measured by the release of corresponding monoamine metabolites. 3-Methoxy-4-hydroxyphenylethylene glycol (MHPG) and vanilmandelic acid (VMA) were used as parameters for the noradrenergic activity, whereas homovanillic acid (HVA) and 5-hydroxyindole-3-acetic acid (5-HIAA) were employed to follow the dopaminergic and serotonergic activity, respectively. For the measurement of the biogenic amine metabolites a published GCMS method has been adapted. Samples of 200 microliters CSF were processed. Following addition of deuterated internal standards and acidification, extraction was carried out with ethyl acetate. Preliminary experiments with the analysis of MHPG using diethyl ether for extraction gave rise to emulsion formation and resulted in poor recoveries for MHPG and in irreproducibility problems due to a preferential extraction of non-labelled MHPG, effects which were not observed with ethyl acetate extraction. Derivatization was done with a mixture of pentafluoropropionic anhydride/pentafluoropropanol (or hexafluoroisopropanol) in order to derivatize both hydroxyl and carboxylic acid groups. The derivatization procedure was optimized for the analysis of 5-HIAA by carrying out a second reaction step with pentafluoropropionic anhydride alone in order to complete the derivatization for the indolic NH moiety. The molecular ions of the derivatized products were selected for detection.(ABSTRACT TRUNCATED AT 250 WORDS)

TRH stimulation test and depression

A thyrotropin-releasing hormone (TRH) stimulation test was performed in 52 male inpatients with major depressive disorder. Twenty-nine percent of the 52 subjects had a delta thyroid-stimulating hormone (ΔTSH) < 5 μU/ml. The cerebrospinal fluid (CSF) amine metabolites, 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5HIAA), were measured in 29 subjects, and a dexamethasone suppression test (DST) was performed in 48 subjects. Of the three CSF amine metabolites, only MHPG correlated significantly with baseline TSH and none correlated with ΔTSH. The baseline TSH correlated positively with the TSH response at 30 minutes. Neither baseline TSH nor ΔTSH correlated with cortisol levels before or after dexamethasone. The correlation between CSF MHPG and serum TSH suggests a relationship between central norepinephrine and baseline TSH.

Diurnal Rhythms of Plasma Cortisol, Beta-Endorphin and Prolactin, and Cerebrospinal Fluid Amine Metabolite Levels before Suicide

There are indications to suggest a relationship between low levels of 5-hydroxy-indoleacetic acid (5HIAA) in the cerebrospinal fluid and suicidal behavior. Many depressed patients show an elevated cortisol secretion. As beta-endorphin is derived from the same precursor as ACTH, it is expected that plasma beta-endorphin levels will also rise in depressed patients. We report here a case of severe depression with diurnal variation who showed low CSF 5HIAA prior to his suicide. In contrast, his catecholamine metabolites were 50% above the mean values of other depressed patients. Hormonal measurements, however, showed low cortisol, prolactin and beta-endorphin levels.

Repeated determination of cerebrospinal fluid amine metabolites by automated direct sampling from an implanted cannula in freely moving rats

A method is described for the automatic sampling of CSF from conscious freely moving rats and the simultaneous determination of 5-HIAA and HVA by high-pressure liquid chromatography with electrochemical detection (HPLC-EC). Timed samples (30 μl) were taken directly from a chronically implanted cannula in the cisterna magna of adult female rats by the HPLC autoinjector. The low volume of sample permitted withdrawal of repeated samples without cross-contamination. The cannula could be used the day after implantation and remained patent for at least two weeks. Treatment with probenecid (200 mg/kg i.p.) caused an increase of both metabolites in the CSF. Pargyline (50 mg/kg i.p.) affected both the 5-HT and dopaminergic systems, reducing their metabolite levels. α-Methyl- p-tyrosine (200 mg/kg i.p.) acted selectively on the catecholaminergic system lowering HVA levels. The method accurately measured amine metabolite changes in the CSF due to pharmacological manipulations.

The clinical syndrome of striatal dopamine deficiency. Parkinsonism induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).

Exposure to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) produces a syndrome that resembles Parkinson's disease. To compare the biochemical abnormalities produced by this compound in human beings with those occurring in Parkinson's disease, we examined biogenic amine metabolites in cerebrospinal fluid and urine from six patients with MPTP-induced parkinsonism and eight patients with Parkinson's disease. In both forms of parkinsonism, the cerebrospinal fluid levels of homovanillic acid, the major metabolite of dopamine, were reduced, whereas the levels of the serotonin metabolite 5-hydroxyindoleacetic acid were normal. The cerebrospinal fluid levels of 3-methoxy-4-hydroxyphenylethylene glycol (MHPG), the major metabolite of norepinephrine in the brain, after adjustment for plasma MHPG, were elevated (greater than 6.0 ng per milliliter) in MPTP-induced parkinsonism, whereas MHPG levels were reduced (less than 6.0) in Parkinson's disease. Neurons containing norepinephrine in the brain are involved in the degenerative process of Parkinson's disease, whereas they are spared in MPTP-induced parkinsonism. The selective destruction by MPTP of nigrostriatal dopamine neurons that is responsible for the movement disorder also appears to result in an increase in central noradrenergic activity, which is not possible in Parkinson's disease. Thus, differences in central noradrenergic activity, reflected in cerebrospinal fluid levels of MHPG, distinguish these two forms of parkinsonism.

The effects of amiflamine on cerebrospinal fluid amine metabolites in the rhesus monkey

Amiflamine, a drug reported to be a reversible inhibitor of monoamine oxidase type A (MAO-A) selective for serotonergic neurons in rodents, was administered to rhesus monkeys over a 12-fold dosage range (0.5–6 mg/kg). Amiflamine produced small, essentially equivalent reductions in cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5-HIAA, 1–28%), 3-methoxy-4-hydroxyphenylglycol (MHPG, 4–26%), and homovanillic acid (HVA, 7–29%), suggesting that the effects of amiflamine are approximately equal on serotonin, norepinephrine and dopamine metabolism in nonhuman primates. Concentrations of amiflamine were very low in CSF 3–6 h after drug administration (< 7 nmol/1), while those of its two major, biologically active metabolites were higher (22–150 nmol/1) and varied in relative proportions among the monkeys. Further investigation is required of some preliminary observations of a possible association between drug metabolite variations and the substantial individual differences in the amine metabolite changes following amiflamine treatment. MAO-B in platelets was not inhibited by 6 mg/kg amiflamine, indicating that MAO-A selectivity was maintained. At low amiflamine doses, early and transient increases in CSF 5-HIAA and HVA concentrations were observed, suggesting an amine-releasing effect of the drug within brain serotonergic and dopaminergic neurons.

Rhesus monkey cerebrospinal fluid amine metabolite changes following treatment with the reversible monoamine oxidase type-A inhibitor cimoxatone

The effects of cimoxatone, a reversible inhibitor of monoamine oxidase type A (MAO-A), on the deaminated metabolites of norepinephrine, dopamine, and serotonin were examined in continuously collected rhesus monkey cerebrospinal fluid (CSF). Cimoxatone, 0.5-8 mg/kg given PO, produced dose-proportionate reductions of 24-h mean CSF 3-methoxy, 4-hydroxy phenylglycol (MHPG) concentrations of 21%-52%. Homovanillic acid (HVA) concentrations also decreased 27%-55%, while CSF 5-hydroxyindoleacetic acid (5-HIAA) decreases were somewhat smaller (7%-32% from baseline). All three metabolite concentrations reached a nadir approximately 6-10 h after drug administration, and required over 40 h to gradually return towards baseline following drug discontinuation. HVA concentration reductions in particular persisted during the entire 24-h period following treatment and were the slowest to return to baseline values. CSF concentrations of cimoxatone and its MAO-inhibiting O-demethyl metabolite showed a parallel time course, peaking 6-10 h after treatment and persisting for up to 24 h in the case of cimoxatone and over 48 h for its metabolite. Single simultaneous time point determinations revealed 10-to 20-fold lower concentrations of cimoxatone and its metabolite in CSF compared to plasma 2 h after treatment. MAO-B activity in platelet-rich plasma was not inhibited by 8 mg/kg cimoxatone, indicating that this drug maintains MAO-A selectivity in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential effects of clorgyline on catecholamine and indoleamine metabolites in the cerebrospinal fluid of rhesus monkeys

The effects of acute and chronic administration of clorgyline, an irreversible inhibitor of monoamine oxidase type A (MAO-A), on the deaminated metabolites of norepinephrine, dopamine and serotonin were examined in rhesus monkey cerebrospinal fluid (CSF). Acute clorgyline treatment resulted in highly significant, dose-dependent reductions in 3-methoxy-4-hydroxyphenylglycol (MHPG) of 50% (1 mg/kg) and 68% (2 mg/kg) compared to pretreatment values. Chronic clorgyline administration (0.25 to 0.5 mg/kg × 24 days) resulted in a 67% reduction in CSF MHPG. In contrast, the concentrations of 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) were less affected by acute clorgyline administration, being reduced significantly only after the 2 mg/kg dose, which lowered 5-HIAA 27% and HVA 48%. Chronic clorgyline treatment had no significant effect on the CSF concentrations of HVA and 5-HIAA. These data, which suggest that MAO-A inhibition by clorgyline in vivo is more closely associated with changes in the noradrenergic than the serotonergic or dopaminergic systems in nonhuman primates, are in general agreement with the effects of clorgyline on CSF and urinary biogenic amine metabolites in man. They differ from several in vitro studies which indicate a primary role of MAO-A in the metabolism of serotonin and of MAO-B in norepinephrine degradation in primate brain. The discrepancies may reflect modulating effects of synaptic feedback mechanisms on the actions of clorgyline in vivo or perhaps a failure of CSF metabolites to adequately reflect brain amine metabolism changes. The lack of change in platelet MAO-B activity during clorgyline treatment together with the minimal changes in HVA concentrations indicate that the selective inhibitory effects of clorgyline on MAO-A were maintained during chronic administration of low drug doses.

Relationship between cerebrospinal fluid amine metabolites, neuroendocrine findings and personality dimensions (Marke-Nyman scale factors) in psychiatric patients.

5-Hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) were measured in the spinal fluid of 45 women hospitalized in a psychiatric department for major depression (14 cases), schizophrenia (18 cases) and alcohol dependence (13 cases). Dexamethasone suppression tests were performed following CSF examinations in all patients, and TRH stimulation tests were also made in six subjects. All biological examinations were carried out in a drug-free state. The Marke-Nyman Temperament scale was administered to all patients as soon as severe psychotic disturbances subsided and sufficient cooperation was achieved, but no later than 10 days following biological examinations. The MNT was repeated after recovery to check reliability of the test results during an episode of a psychiatric disorder. CSF amine metabolite concentrations did not differ significantly in the three patient groups; postdexamethasone average cortisol levels were above the critical level (5 micrograms/dl) in each group, the highest values being found in major depression. One of the three MNT factors was inhomogeneous among diagnostic groups (validity: low in depression and alcoholism), but the other two also differed from a healthy control population. Correlation structure between biological and psychological variables was homogeneous throughout the diagnoses and a significant inverse correlation was found only between CSF 5-HIAA and the validity factor of MNT. Maximal TSH response to TRH stimulation correlated with both solidity and stability in the MNT scale. Since MNT results proved to be stable even during an illness episode, a possible link is suggested between personality traits and central serotonin metabolism.