Upregulation of Heat-Shock Protein (hsp)-27 in a Patient with Heterozygous SPG11 c.1951C>T and SYNJ1 c.2614G>T Mutations Causing Clinical Spastic Paraplegia.

We report a 49-year-old patient suffering from spastic paraplegia with a novel heterozygous mutation and analyzed the levels of heat shock proteins (hsp)-27, dopamine (DA), and its metabolites in their cerebrospinal fluid (CSF). The hsp27 protein concentration in the patient's CSF was assayed by an ELISA kit, while DA levels and its metabolites in the CSF, 3,4-dihydroxyphenylacetic acid (DOPAC), Cys-DA, and Cys-DOPA were measured by HPLC. Whole exome sequencing demonstrated SPG-11 c.1951C>T and novel SYNJ1 c.2614G>T mutations, both heterozygous recessive. The patient's DA and DOPAC levels in their CSF were significantly decreased (53.0 ± 6.92 and 473.3 ± 72.19, p < 0.05, respectively) while no differences were found in their Cys-DA. Nonetheless, Cys-DA/DOPAC ratio (0.213 ± 0.024, p < 0.05) and hsp27 levels (1073.0 ± 136.4, p < 0.05) were significantly higher. To the best of our knowledge, the c.2614G>T SYNJ1 mutation has not been previously reported. Our patient does not produce fully functional spatacsin and synaptojanin-1 proteins. In this line, our results showed decreased DA and DOPAC levels in the patient's CSF, indicating loss of DAergic neurons. Many factors have been described as being responsible for the increased cys-DA/DOPAC ratio, such as MAO inhibition and decreased antioxidant activity in DAergic neurons which would increase catecholquinones and consequently cysteinyl-catechols. In conclusion, haploinsufficiency of spatacsin and synaptojanin-1 proteins might be the underlying cause of neurodegeneration produced by protein trafficking defects, DA vesicle trafficking/recycling processes, autophagy dysfunction, and cell death leading to hsp27 upregulation as a cellular mechanism of protection and/or to balance impaired protein trafficking.

Differential abnormalities of cerebrospinal fluid dopaminergic versus noradrenergic indices in synucleinopathies.

The synucleinopathies Parkinson's disease (PD), multiple system atrophy (MSA), and pure autonomic failure (PAF) are characterized by intra-cytoplasmic deposition of the protein alpha-synuclein and by catecholamine depletion. PAF, which manifests with neurogenic orthostatic hypotension (nOH) and no motor signs of central neurodegeneration, can evolve into PD+nOH. The cerebrospinal fluid (CSF) levels of catecholamine metabolites may indicate central catecholamine deficiency in these synucleinopathies, but the literature is inconsistent and incomplete. In this retrospective cohort study we reviewed data about CSF catecholamines, the dopamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and the norepinephrine metabolites 3,4-dihydroxyphenylglycol (DHPG) and 3-methoxy-4-hydroxyphenylglycol (MHPG). The compounds were measured in 36 patients with PD, 37 patients with MSA, and 19 patients with PAF and in 38 controls. Compared to the control group, the PD, MSA, and PAF groups had decreased CSF MHPG (p < .0001 each by Dunnett's post hoc test), DHPG (p = .004; p < .0001; p < .0001) and norepinephrine (p = .017; p = .0003; p = .044). CSF HVA and DOPAC were decreased in PD (p < .0001 each) and MSA (p < .0001 each) but not in PAF. The three synucleinopathies therefore have in common in vivo evidence of central noradrenergic deficiency but differ in the extents of central dopaminergic deficiency-prominent in PD and MSA, less apparent in PAF. Data from putamen 18 F-DOPA and cardiac 18 F-dopamine neuroimaging in the same patients, post-mortem tissue catecholamines in largely separate cohorts, and review of the neuropathology literature fit with these distinctions. The results suggest a 'norepinephrine first' ascending pathogenetic sequence in synucleinopathies, with degeneration of pontine locus ceruleus noradrenergic neurons preceding the loss of midbrain substantia nigra dopaminergic neurons.

Pharmacokinetics and pharmacodynamics of a single dose Nilotinib in individuals with Parkinson's disease.

Nilotinib is a broad-based tyrosine kinase inhibitor with the highest affinity to inhibit Abelson (c-Abl) and discoidin domain receptors (DDR1/2). Preclinical evidence indicates that Nilotinib reduces the level of brain alpha-synuclein and attenuates inflammation in models of Parkinson's disease (PD). We previously showed that Nilotinib penetrates the blood-brain barrier (BBB) and potentially improves clinical outcomes in individuals with PD and dementia with Lewy bodies (DLB). We performed a physiologically based population pharmacokinetic/pharmacodynamic (popPK/PD) study to determine the effects of Nilotinib in a cohort of 75 PD participants. Participants were randomized (1:1:1:1:1) into five groups (n = 15) and received open-label random single dose (RSD) 150:200:300:400 mg Nilotinib vs placebo. Plasma and cerebrospinal fluid (CSF) were collected at 1, 2, 3, and 4 hours after Nilotinib administration. The results show that Nilotinib enters the brain in a dose-independent manner and 200 mg Nilotinib increases the level of 3,4-Dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), suggesting alteration to dopamine metabolism. Nilotinib significantly reduces plasma total alpha-synuclein and appears to reduce CSF oligomeric: total alpha-synuclein ratio. Furthermore, Nilotinib significantly increases the CSF level of triggering receptors on myeloid cells (TREM)-2, suggesting an anti-inflammatory effect. Taken together, 200 mg Nilotinib appears to be an optimal single dose that concurrently reduces inflammation and engages surrogate disease biomarkers, including dopamine metabolism and alpha-synuclein.

Cerebrospinal fluid biomarkers of central dopamine deficiency predict Parkinson's disease.

BACKGROUND: Consistent with nigrostriatal dopamine depletion, low cerebrospinal fluid (CSF) concentrations of 3,4-dihydroxyphenylacetic acid (DOPAC), the main neuronal metabolite of dopamine, characterize Parkinson's disease (PD) even in recently diagnosed patients. Whether low CSF levels of DOPAC or DOPA, the precursor of dopamine, identify pre-clinical PD in at-risk healthy individuals has been unknown. METHODS: Participants in the intramural NINDS PDRisk study entered information about family history of PD, olfactory dysfunction, dream enactment behavior, and orthostatic hypotension at a protocol-specific website. After at least 3 risk factors were confirmed by on-site screening, 26 subjects had CSF sampled for levels of catechols and were followed for at least 3 years. RESULTS: Of 26 PDRisk subjects, 4 were diagnosed with PD (Pre-Clinical PD group); 22 risk-matched (mean 3.2 risk factors) subjects remained disease-free after a median of 3.7 years (No-PD group). The Pre-Clinical PD group had lower initial DOPA and DOPAC levels than did the No-PD group (p = 0.0302, p = 0.0190). All 3 subjects with both low DOPA (<2.63 pmol/mL) and low DOPAC (<1.22 pmol/mL) levels, based on optimum cut-off points using the minimum distance method, developed PD, whereas none of 14 subjects with both normal DOPA and DOPAC levels did so (75% sensitivity at 100% specificity, p = 0.0015 by 2-tailed Fisher's exact test). CONCLUSIONS: In people with multiple PD risk factors, those with low CSF DOPA and low CSF DOPAC levels develop clinical disease during follow-up. We suggest that neurochemical biomarkers of central dopamine deficiency identify the disease in a pre-clinical phase.

Cerebrospinal fluid levels of catecholamines and its metabolites in Parkinson's disease: effect of l-DOPA treatment and changes in levodopa-induced dyskinesia.

Levodopa (l-DOPA, l-3,4-dihydroxyphenylalanine) is the most effective drug in the symptomatic treatment of Parkinson's disease (PD), but chronic use initiates a maladaptive process leading to l-DOPA-induced dyskinesia (LID). Risk factors for early onset LID include younger age, more severe disease at baseline and higher daily l-DOPA dose, but biomarkers to predict the risk of motor complications are not yet available. Here, we investigated whether CSF levels of catecholamines and its metabolites are altered in PD patients with LID [PD-LID, n = 8)] as compared to non-dyskinetic PD patients receiving l-DOPA (PD-L, n = 6), or not receiving l-DOPA (PD-N, n = 7) as well as non-PD controls (n = 16). PD patients were clinically assessed using the Unified Parkinson's Disease Rating Scale and Unified Dyskinesia Rating Scale and CSF was collected after overnight fasting and 1-2 h after oral intake of l-DOPA or other anti-Parkinson medication. CSF catecholamines and its metabolites were analyzed by HPLC with electrochemical detection. We observed (i) decreased levels of dihydroxyphenylacetic acid (DOPAC) and homovanillic acid in PD patients not receiving l-DOPA (ii) higher dopamine (DA) levels in PD-LID as compared to controls (iii) higher DA/l-DOPA and lower DOPAC/DA ratio's in PD-LID as compared to PD-L and (iv) an age-dependent increase of DA and decrease of DOPAC/DA ratio in controls. These results suggest increased DA release from non-DA cells and deficient DA re-uptake in PD-LID. Monitoring DA and DOPAC in CSF of l-DOPA-treated PD patients may help identify patients at risk of developing LID.

Elevated cerebrospinal fluid ratios of cysteinyl-dopamine/3,4-dihydroxyphenylacetic acid in parkinsonian synucleinopathies.

INTRODUCTION: There is intense interest in identifying cerebrospinal fluid (CSF) biomarkers of Parkinson's disease (PD), both for early diagnosis and to track effects of putative treatments. Nigrostriatal dopamine depletion characterizes PD. Predictably, CSF levels of 3,4-dihydroxyphenylacetic acid (DOPAC), the main neuronal metabolite of dopamine, are decreased in PD, even in patients with recent onset of the movement disorder. Whether low CSF DOPAC is associated specifically with parkinsonism has been unclear. In the neuronal cytoplasm dopamine undergoes not only enzymatic oxidation to form DOPAC but also spontaneous oxidation to form 5-S-cysteinyl-dopamine (Cys-DA). Theoretically, oxidative stress or decreased activity of aldehyde dehydrogenase (ALDH) in the residual nigrostriatal dopaminergic neurons would increase CSF Cys-DA levels with respect to DOPAC levels. PD, parkinsonian multiple system atrophy (MSA-P), and pure autonomic failure (PAF) are synucleinopathies; however, PAF does not entail parkinsonism. We examined whether an elevated Cys-DA/DOPAC ratio provides a specific biomarker of parkinsonism in synucleinopathy patients. METHODS: CSF catechols were assayed in PD (n = 24), MSA-P (n = 32), PAF (n = 18), and control subjects (n = 32). RESULTS: Compared to controls, CSF DOPAC was decreased in PD and MSA-P (p < 0.0001 each). In both diseases Cys-DA/DOPAC ratios averaged more than twice control (0.14 ± 0.02 and 0.13 ± 0.02 vs. 0.05 ± 0.01, p < 0.0001 each), whereas in PAF the mean Cys-DA/DOPAC ratio was normal (0.05 ± 0.01). CONCLUSIONS: CSF Cys-DA/DOPAC ratios are substantially increased in PD and MSA-P and are normal in PAF. Thus, in synucleinopathies an elevated CSF Cys-DA/DOPAC ratio seems to provide a specific biomarker of parkinsonism.

5-HT(1A) receptor antagonist improves behavior performance of delirium rats through inhibiting PI3K/Akt/mTOR activation-induced NLRP3 activity.

Postoperative delirium is a common complication that often results in poor outcomes in surgical and elderly patients. Accumulating evidences suggest that the pathophysiology of delirium results from multiple neurotransmitter system dysfunctions. To further clarify the effects of the selective serotonin (5-HT) (1A) antagonist WAY-100635 on the behaviors in scopolamine induced-delirium rats and to explore the molecular mechanism, in this study, we investigated the change of monoamine levels in the cerebrospinal fluid (CSF) and different brain regions using high-performance liquid chromatography and assessed the behavioral retrieval of delirium rats treated with WAY-100635. It was found that 5-hydroxy-3-indoleacetic acid (5-HIAA), 3,4-dihydroxyphenylacetic acid, and homovanillic acid concentrations in the CSF of scopolamine-induced delirium rats were significantly increased, among which 5-HIAA was also increased in hippocampus and basolateral amygdala (BLA), and 5-HT(1A) receptor was significantly higher in the hippocampuses and BLA than other brain regions. Furthermore, intrahippocampus and intra-BLA stereotactic injection of WAY-100635 improved the delirium-like behavior of rats. Mechanistically, after WAY-100635 treatment, significant reduction of IL-1ß release into CSF and NOD-like receptor family, pyrin domain containing 3 (NLRP3) expression, phosphorylated phosphatidylinositol-3-kinase (PI3K), protein kinase B (AKT), and S6K was observed. Altogether, these results suggest that delirium rats induced by scopolamine may be correlated with an increased cerebral concentration of 5-HT and dopamine neurotransmitters system; the selective 5-HT(1A) antagoniszts can reverse the delirium symptoms at some extent through tendering PI3K/Akt/mammalian target of rapamycin complex 1 (mTOR) activation-induced NLRP3 activity and then reducing IL-1ß release.

A validated LC-MS/MS method for neurotransmitter metabolite analysis in human cerebrospinal fluid using benzoyl chloride derivatization.

BACKGROUND: Human cerebrospinal fluid (CSF) is often acquired in Phase I clinical trials to assess the CNS penetration of new pharmacological agents and to search for biomarkers associated with PD effects. Robust methods for neurotransmitter metabolites in CSF have proven elusive, in part due to inadequate reversed phase LC retention. RESULTS: Benzoyl chloride derivatization was used to promote retention for LC-MS/MS for a panel of neurotransmitter metabolites while delivering a concise method for sample preparation. CONCLUSION: A validated assay in human CSF was obtained for 3,4-dihydroxyphenylacetic acid, homovanillic acid, 3,4-dihydroxyphenylglycol and 5-hydroxyindoleacetic acid. This method is differentiated from other LC-MS/MS methods by delivering results in line with full regulatory expectations.

Fluoxetine: juvenile pharmacokinetics in a nonhuman primate model.

RATIONALE: The selective serotonin reuptake inhibitor (SSRI) fluoxetine is the only psychopharmacological agent approved for use in children. While short-term studies of side effects have been performed, long-term consequences for brain development are not known. Such studies can be performed in appropriate animal models if doses modeling therapeutic use in children are known. OBJECTIVES: The goal of this study was to identify a daily dose of fluoxetine in juvenile monkeys which would result in serum fluoxetine and norfluoxetine concentrations in the therapeutic range for children. METHODS: Juvenile (2.5-year-old rhesus monkeys, n = 6) received single administration of doses of 1, 2, and 4 mg/kg day fluoxetine on a background of chronic dosing at an intermediate level to provide steady-state conditions to model therapeutic administration. Using nonlinear modeling, standard pharmacokinetic parameters were derived. Cerebrospinal fluid monoamine neurotransmitters were assayed to confirm the pharmacological effects. RESULTS: Dose-dependent area under the curve (AUC) and C max values were seen, while T max and absorption/elimination half-lives were minimally influenced by dose. A dosage of 2 mg/kg day given over a 14-week period led to steady-state serum concentrations of active agent (fluoxetine + norfluoxetine) similar to those recorded from drug monitoring studies in children. Cisternal cerebrospinal fluid concentrations of serotonin increased significantly over the 14-week period, while concentrations of the serotonin metabolite (5-HIAA) were lower but not significantly different. CONCLUSIONS: A dose of 2 mg/kg day fluoxetine in juvenile rhesus monkeys provides an internal dose similar to therapeutic use in children and will help establish a valuable animal model for understanding fluoxetine's therapeutic and potential adverse effects in children.

Cerebrospinal fluid biomarkers of central catecholamine deficiency in Parkinson's disease and other synucleinopathies.

Central catecholamine deficiency characterizes α-synucleinopathies such as Parkinson's disease. We hypothesized that cerebrospinal fluid levels of neuronal metabolites of catecholamines provide neurochemical biomarkers of these disorders. To test this hypothesis we measured cerebrospinal fluid levels of catechols including dopamine, norepinephrine and their main respective neuronal metabolites dihydroxyphenylacetic acid and dihydroxyphenylglycol in Parkinson's disease and two other synucleinopathies, multiple system atrophy and pure autonomic failure. Cerebrospinal fluid catechols were assayed in 146 subjects-108 synucleinopathy patients (34 Parkinson's disease, 54 multiple system atrophy, 20 pure autonomic failure) and 38 controls. In 14 patients cerebrospinal fluid was obtained before or within 2 years after the onset of parkinsonism. The Parkinson's disease, multiple system atrophy and pure autonomic failure groups all had lower cerebrospinal fluid dihydroxyphenylacetic acid [0.86 ± 0.09 (SEM), 1.00 ± 0.09, 1.32 ± 0.12 nmol/l] than controls (2.15 ± 0.18 nmol/l; P < 0.0001; P < 0.0001; P = 0.0002). Dihydroxyphenylglycol was also lower in the three synucleinopathies (8.82 ± 0.44, 7.75 ± 0.42, 5.82 ± 0.65 nmol/l) than controls (11.0 ± 0.62 nmol/l; P = 0.009, P < 0.0001, P < 0.0001). Dihydroxyphenylacetic acid was lower and dihydroxyphenylglycol higher in Parkinson's disease than in pure autonomic failure. Dihydroxyphenylacetic acid was 100% sensitive at 89% specificity in separating patients with recent onset of parkinsonism from controls but was of no value in differentiating Parkinson's disease from multiple system atrophy. Synucleinopathies feature cerebrospinal fluid neurochemical evidence for central dopamine and norepinephrine deficiency. Parkinson's disease and pure autonomic failure involve differential dopaminergic versus noradrenergic lesions. Cerebrospinal fluid dihydroxyphenylacetic acid seems to provide a sensitive means to identify even early Parkinson's disease.

Determinants of central sympathetic activation in spontaneous primary subarachnoid hemorrhage.

BACKGROUND: Subarachnoid hemorrhage (SAH) has been associated with pronounced acute sympathetic activation. The purpose of this investigation is to identify demographic, clinical, radiological, and anatomical features of SAH that relate to sympathetic activation. METHODS: Observational study of consecutive Grades 3-5 SAH patients requiring ventriculostomy and undergoing endovascular aneurysmal obliteration. All patients underwent cerebrospinal fluid (CSF) sampling within 48 h of SAH onset, and samples were assayed for various catecholamine compounds and metabolites. Univariate analyses were performed to identify variables associated with catecholamine levels, and to correlate linearity among catecholamine compounds and metabolites. Variables demonstrating a possible association and variables of interest were entered into linear regression models to determine predictors of catecholamine elevations. RESULTS: Of the 102 patients, mean age was 58 years and 74% were female; 42% were Hunt-Hess (H/H) grade 4/5, 61% had a computed tomography (CT) score of 3/4, 57% had anterior cerebral or communicating artery (ACA/ACom) aneursysms, and 23% had aneurysms in the posterior circulation. In the univariate analysis, age, gender, H/H grade, CT score, and aneurysm location demonstrated various associations with catecholamine levels, and substantial positive correlations existed between the various catecholamine compounds and metabolites. Linear regression analyses revealed H/H grade to be an independent predictor of elevated CSF epinephrine (EPI), 3,4-dihydroxyphenylalanine (DOPA) and 3,4-dihydroxyphenyl acetic acid (DOPAC) levels, and of the norepinephrine/3,4-dihydroxyphenylglycol (NE/DHPG) ratio (p < 0.05 for all analyses). Female gender independently predicted increased dopamine (DA) and DOPAC levels (p < 0.05 for two analyses), as well as possibly DOPA levels (p < 0.1). Age, CT score and aneurysm location demonstrated only inconsistent associations and trends. CONCLUSIONS: Central sympathetic activation relates to clinical severity and female gender. No definitive associations were found for age, hemorrhage amount, or aneurysm location.

Effects of a novel mGlu2/3 receptor agonist prodrug, LY2140023 monohydrate, on central monoamine turnover as determined in human and rat cerebrospinal fluid.

RATIONALE: Accumulating evidence suggests that the primary symptoms of schizophrenia may be associated with altered central glutamate transmission. LY2140023 monohydrate is the methionine prodrug of the selective mGlu(2/3) receptor agonist LY404039 and is currently being assessed for the treatment of schizophrenia. OBJECTIVE: The objective of this study was to evaluate the central pharmacological activity of LY2140023 monohydrate in preclinical and clinical studies. METHODS: Effects on neurotransmitter/metabolite concentrations were assessed in male rats following single oral doses of LY2140023 monohydrate (microdiasylates from the prefrontal cortex), single intraperitoneal injection of LY404039 [cerebrospinal fluid (CSF)], or LY2140023 monohydrate dosed once daily for 7 days (CSF). A clinical study in 16 healthy subjects assessed the effects of LY2140023 monohydrate 40 mg orally twice daily for 14 days in lumbar CSF. RESULTS: Rat studies: Acute dosing with LY2140023 monohydrate resulted in significant dose-dependent increases in extracellular concentrations of dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), but not 5-hydroxyindoleacetic acid (5-HIAA), in the prefrontal cortex. LY2140023 monohydrate dosing for 7 days elevated the concentrations of HVA in CSF, while acutely dosed LY404039 increased the concentrations of DOPAC, HVA, and methoxy-hydroxyphenylglycol (MHPG), but not 5-HIAA. Clinical study: Significant increases were seen for DOPAC, HVA, 5-HIAA, and MHPG in the CSF of subjects receiving LY2140023 monohydrate, but not placebo. CONCLUSIONS: LY2140023 monohydrate and/or LY404039 dosing potently affected dopamine turnover and also significantly affected serotonin turnover in the human and rat central nervous systems. The measurement of biogenic amine metabolites such as DOPAC and HVA may serve as useful biomarkers of LY2140023 monohydrate and/or LY404039 central pharmacodynamic activity.

CSF catecholamine profile in subarachnoid hemorrhage patients with neurogenic cardiomyopathy.

BACKGROUND: Patients experiencing apoplectic intracranial processes may develop neurogenic cardiomyopathy (NC). The purpose of this research is to determine whether cerebrospinal fluid (CSF) catecholamine levels are elevated in subarachnoid hemorrhage (SAH) patients with NC when compared to those without NC. METHODS: Observational study of consecutive grades 3-5 SAH patients requiring ventriculostomy. All patients underwent CSF sampling for catecholamine levels, and transthoracic echocardiography (TTE) to assess for NC, within 48 h of SAH onset. Univariate analyses were performed to identify clinical and laboratory variables associated with NC. Clinical variables associated with NC in the univariate analysis were entered into logistic regression models along with the candidate catecholamine variables to identify predictors of NC. RESULTS: The study group contained 100 patients--mean age of study subjects was 58 years, 73% were female, and 15% developed NC. NC patients were more likely to have a worse clinical grade than patients without NC (80 vs. 34%, P = 0.001). NC patients possessed greater DOPA levels (5.83 vs. 4.60 nmol/l, P = 0.044), and a trend toward greater noradrenergic activity as determined by NE/DHPG ratio (0.3799 vs. 0.2519, P = 0.073). Multivariate analysis identified worse clinical grade (OR 7.09, P = 0.005) and possibly NE levels (OR 1.005, P = 0.057) as independent predictors of NC. Bivariate analysis reinforced the findings for NE (OR 1.006, P = 0.022), and also identified DOPA levels (OR 1.001, P = 0.034) and NE/DHPG (OR 22.18, P = 0.019) as predictors of NC. CONCLUSIONS: SAH patients with NC tend to have greater CSF catecholamine levels than those without NC. However, the development of NC may also be related to factors not evaluated by our study.

Extracción de metabolitos ácidos durante el análisis de catecolaminas en tejido cerebral de ratas / Extraction of acid metabolites during the analysis of catecholamines in rat brain tissue / Extração de metabólitos ácidos durante a análise de catecolaminas no tecido cérebro de rato

A través del método de equilibrio batch se comparó la adsorción de las catecolaminas Dopamina (DA), Noradrenalina (NA) y Adrenalina (A), y de los metabolitos ácido dihidroxifenilacético (Dopac) y ácido indolacético (5- HIAA) en las fases sólidas octadecil (C18) hidrofóbica, diol (C Diol) hidrofílica y de intercambio catiónico débil (WCX). En la fase sólida WCX a pH 4,0 se observó un 78% de adsorción de catecolaminas y 68% de adsorción de Dopac. Las isotermas de adsorción de las catecolaminas en la fase WCX son de tipo Langmuir. La adrenalina tiene mayor afinidad que la dopamina por la fase WCX a pH 4,0 y la dopamina mayor afinidad que el Dopac y éste es coadsorbido sobre las catecolaminas adsorbidas en la fase WCX. Un ensayo con solventes orgánicos demostró que el tolueno extrajo selectivamente de una mezcla sintética el Dopac y el 5-HIAA coadsorbido, mientras que en una muestra de tejido cerebral de ratas experimentales fueron extraídos el Dopac y el ácido homovanílico (HVA). Estos resultados sirvieron para proponer un paso adicional de extracción con solventes orgánicos para la separación de metabolitos ácidos durante la extracción en fase sólida (EFS) en el análisis de catecolaminas.

The adsorptions of Dopamine (DA), Noradrenaline (NA), and Adrenaline (A) catecholamines were compared by using the batch equilibrium method, as well as those of the dihydroxyphenylacetic acid (Dopac) and indolacetic acid (5-HIAA) metabolites on the hydrophobic octadecyl (C18), hydrophilic diol (C Diol) and weak cation exchange (WCX) solid phases. On the WCX solid phase at pH 4.0, catecholamines adsorption of 78% and Dopac adsorption of 68% were observed. The adsorption isotherms of catecholamines on the for the WCX phase at pH 4.0 than dopamine, dopamine has greater affinity than Dopac, and this latter is coadsorbed over the adsorbed catecholamines on the WCX phase. A trial with organic solvents demonstrated that toluene selectively extracted Dopac and the coadsorbed 5-HIAA from a synthetic mix, while in a brain tissue specimen from experimental rats, Dopac and homovanilic acid (HVA) were extracted. These results served to propose an additional extraction step with organic solvents throughout the separation of acid metabolites during solid phase extraction (EFS) for the analysis of catecholamines.

Increased dopaminergic neurotransmission in therapy-naïve asymptomatic HIV patients is not associated with adaptive changes at the dopaminergic synapses.

Central dopaminergic (DA) systems are affected during human immunodeficiency virus (HIV) infection. So far, it is believed that they degenerate with progression of HIV disease because deterioration of DA systems is evident in advanced stages of infection. In this manuscript we found that (a) DA levels are increased and DA turnover is decreased in CSF of therapy-naïve HIV patients in asymptomatic infection, (b) DA increase does not modulate the availability of DA transporters and D2-receptors, (c) DA correlates inversely with CD4+ numbers in blood. These findings show activation of central DA systems without development of adaptive responses at DA synapses in asymptomatic HIV infection. It is probable that DA deterioration in advanced stages of HIV infection may derive from increased DA availability in early infection, resulting in DA neurotoxicity. Our findings provide a clue to the synergism between DA medication or drugs of abuse and HIV infection to exacerbate and accelerate HIV neuropsychiatric disease, a central issue in the neurobiology of HIV.

Relationship between dopamine D2 receptor occupancy, clinical response, and drug and monoamine metabolites levels in plasma and cerebrospinal fluid. A pilot study in patients suffering from first-episode schizophrenia treated with quetiapine.

Combining measurements of the monoamine metabolites in the cerebrospinal fluid (CSF) and neuroimaging can increase efficiency of drug discovery for treatment of brain disorders. To address this question, we examined five drug-naïve patients suffering from schizophrenic disorder. Patients were assessed clinically, using the Positive and Negative Syndrome Scale (PANSS): at baseline and then at weekly intervals. Plasma and CSF levels of quetiapine and norquetiapine as well CSF 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5-hydroxyindole-acetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were obtained at baseline and again after at least a 4 week medication trail with 600 mg/day quetiapine. CSF monoamine metabolites levels were compared with dopamine D(2) receptor occupancy (DA-D(2)) using [(18)F]fallypride and positron emission tomography (PET). Quetiapine produced preferential occupancy of parietal cortex vs. putamenal DA-D(2), 41.4% (p<0.05, corrected for multiple comparisons). DA-D(2) receptor occupancies in the occipital and parietal cortex were correlated with CSF quetiapine and norquetiapine levels (p<0.01 and p<0.05, respectively). CSF monoamine metabolites were significantly increased after treatment and correlated with regional receptor occupancies in the putamen [DOPAC: (p<0.01) and HVA: (p<0.05)], caudate nucleus [HVA: (p<0.01)], thalamus [MHPG: (p<0.05)] and in the temporal cortex [HVA: (p<0.05) and 5-HIAA: (p<0.05)]. This suggests that CSF monoamine metabolites levels reflect the effects of quetiapine treatment on neurotransmitters in vivo and indicates that monitoring plasma and CSF quetiapine and norquetiapine levels may be of clinical relevance.

Substantia nigra hyperechogenicity and CSF dopamine depletion in HIV.

Dopaminergic dysfunction is thought to play a pivotal role in human immunodeficiency virus (HIV)-related dementia. Decreased dopamine (DA) levels in the cerebrospinal fluid (CSF) and neuronal loss in the substantia nigra (SN) have been reported in HIV-infected patients, suggesting nigrostriatal damage. Structural changes detectable as hyperechogenicity in transcranial ultrasound (TCS) scans of the SN have been reported in patients with Parkinson's disease (PD) and other neurological conditions. In this study, we assessed the echomorphology of the SN in 40 HIV-positive patients compared to 40 age- and sex-matched healthy controls and correlated these findings with CSF levels of DA and the metabolites homovanillic acid (HVA) and 3,4-dihydroxy phenylacetic acid (DOPAC) and with neuropsychologic performance. We observed that the SN of HIV-infected patients was hyperechogenic relative to that of controls (0.07 +/- 0.05 vs. 0.04 +/- 0.07 cm(2); mean +/- SEM; P < 0.001) and that this SN hyperechogenicity was correlated with decreased DA levels in the CSF, decreased CD4 cell count, and an impaired performance in the psychopathology assessment scale (AMDP) subtest for drive and psychomobility. An association to CDC stage, duration of HIV infection, or presence of HIV dementia was not observed. Our results indicate changes in the nigrostriatal system in HIV-infected patients that are detectable as hyperechogenic SN precede prominent extrapyramidal symptoms and cognitive dysfunction.

A history of iron deficiency anemia during infancy alters brain monoamine activity later in juvenile monkeys.

Both during and after a period of iron deficiency (ID), iron-dependent neural processes are affected, which raises the potential concern that the anemia commonly experienced by many growing infants could have a protracted effect on the developing brain. To further investigate the effects of ID on the immature brain, 49 infant rhesus monkeys were evaluated across the first year of life. The mothers, and subsequently the infants after weaning, were maintained on a standardized diet containing 180 mg/kg of iron and were not provided other iron-rich foods as treats or supplements. As the infants grew, they were all screened with hematological tests, which documented that 16 (33.3%) became markedly ID between 4 and 8 months of age. During this anemic period and subsequently at 1 year of age, cerebrospinal fluid (CSF) specimens were collected to compare monoamine activity in the ID and iron-sufficient infants. Monoamine neurotransmitters and metabolite levels were normal at 4 and 8 months of age, but by 1 year the formerly anemic monkeys had significantly lower dopamine and significantly higher norepinephrine levels. These findings indicate that ID can affect the developmental trajectory of these two important neurotransmitter systems, which are associated with emotionality and behavioral performance, and further that the impact in the young monkey was most evident during the period of recovery.

Circadian rhythm of CSF monoamines and hypocretin-1 in restless legs syndrome and Parkinson's disease.

The symptoms of restless legs syndrome (RLS) have a circadian pattern and central nervous system dopamine has been implicated in the pathogenesis of the condition. We sought to characterize circadian variation in dopamine and related compounds in human cerebro-spinal fluid (CSF). CSF was continuously withdrawn for 22 h from an implanted lumbar intradural catheter and sampled from three patients with RLS, three patients with Parkinson's disease (PD) and three healthy volunteers. Patients had moderate disease severity and took no medications. We assayed CSF dopamine (DA), homovanillic acid (HVA), dihydroxy-phenylacetic acid (DOPAC) and 5-hydroxyindole acetic acid (5-HIAA) from samples every 30 min by reversed-phase HPLC coupled with electrochemical detection. We also measured CSF levels of hypocretin-1 every hour by RIA. The procedure was well-tolerated. One patient ended the study early due to lumbar radicular pain and was not included in the analysis. There were no changes in CSF cell counts or protein levels from the first to the last samples. There was no difference in any of the compounds between groups, so we fit 24-h cosines to examine if the entire group had significant phase consistency. There was a peak for dopamine at 10 a.m. (p<0.025) and for HVA at 2 p.m. (p<0.01), but no evidence of a significant 24-h rhythm for DOPAC, 5-HIAA, the HVA/5-HIAA ratio, or hypocretin-1. These results demonstrate a circadian rhythm for CSF dopamine and HVA concentrations in humans, with higher levels in the daytime than at nighttime. This circadian variation could underlie the symptoms of RLS and sleep-related variation in motor function in PD.

Correlation between changes in CSF dopamine turnover and development of dyskinesia in Parkinson's disease.

To assess possible differences in dopamine metabolism that could parallel disease progression in Parkinson's disease (PD), we measured dopamine (DA) and its metabolites in the cerebrospinal fluid (CSF) in PD patients at different stages of disease: de novo (DEN), advanced not showing dyskinesias (ADV), and advanced with dyskinesias (DYS). DA, homovanillic acid (HVA) and dihydroxyphenylacetic acid (DOPAC) were significantly higher in DEN patients compared with other groups. A negative exponential correlation related DA level and disease duration. The HVA/DA ratio was significantly higher in the ADV and DYS group than that found in DEN group. Our data show that disease progression produces an early large decay of DA levels, followed by a stabilization. On the contrary, a late change in DA turnover (increased HVA/DA ratio) is documented in patients with longer disease duration. Our results suggest that the appearance of dyskinesia may not be related to a further loss of DA terminals but to a different, abnormal, DA turnover.