Homovanillic acid and dopamine-beta-hydroxylase in male youth: relationships with paternal substance abuse and antisocial behavior

Neurotransmitter metabolites in milk ferments of Leuconostoc mesenteroides regulate temperature-sensitive heartbeats in an ex ovo model

Accumulated evidence has supported the probiotic activity of Leuconostoc mesenteroides (L. mesenteroides) which can yield beneficial metabolites via fermentation. Here, bovine milk rich in phenylalanine（PHE) was used as a source for fermentation of L. mesenteroides. The complexes of PHE with bacterial phenylalanine hydroxylase (PheH) at two temperatures were revealed via molecular dynamics simulation. Two carbon hydrogen bonds and a Pi-Alkyl T-shaped interaction were newly formed at an active site of the PheH-PHE complex. The PheH interacted with two different hydrogen atoms in an amine of PHE via conventional hydrogen bonds at 37 °C, a temperature that accelerated the milk fermentation of L. mesenteroides. Twenty-eight metabolites including various neurotransmitters in fermented milk were identified and quantified by liquid chromatography coupled to quadrupole ion trap (Q-Trap) tandem mass spectrometry. Ex ovo injection of milk ferments into the yolk sac of chicken embryos enhanced a rising temperature-induced increase in heartbeats towards the normal resting level. The neurotransmitter-rich milk ferments hold potential for using to adjust energy metabolism, referred from heart rates, during fluctuating temperature conditions.

Serum brain-derived neurotrophic factor levels and cocaine-induced transient psychotic symptoms

BACKGROUND

Cocaine-induced psychosis (CIP) is among the most serious adverse effects of cocaine. Reduced serum brain-derived neurotrophic factor (BDNF) levels have been reported in schizophrenia and psychosis; however, studies assessing the involvement of BDNF in CIP are lacking.

METHODS

A total of 22 cocaine-dependent patients (aged 33.65 ± 6.85) who had never experienced psychotic symptoms under the influence of cocaine (non-CIP) and 18 patients (aged 34.18 ± 8.54) with a history of CIP completed a 2-week detoxification program in an inpatient facility. Two serum samples were collected from each patient at baseline and at the end of the protocol. Demographic, consumption and clinical data were recorded for all patients. A paired group of healthy controls was also included.

RESULTS

At the beginning of the detoxification treatment, serum BDNF levels were similar in both the non-CIP and the CIP groups. During early abstinence, the non-CIP group exhibited a significant increase in serum BDNF levels (p = 0.030), whereas the CIP group exhibited a decrease. Improvements in depression (Beck Depression Inventory, BDI, p = 0.003) and withdrawal symptoms (Cocaine Selective Severity Assessment, CSSA, p = 0.013) show a significant positive correlation with serum BDNF levels in the non-CIP group, whereas no correlation between the same variables was found in the CIP group.

CONCLUSIONS

This study suggests that BDNF plays a role in the transient psychotic symptoms associated with cocaine consumption. In the non-CIP group, the increase in serum BDNF appears to be driven by the effects of chronic cocaine consumption and withdrawal. In contrast, patients with CIP share some of the neurotrophic deficiencies that characterize schizophrenia and psychosis.

Association between dopamine Beta-hydroxylase gene polymorphisms and attention-deficit hyperactivity disorder in korean children

Attention-deficit hyperactivity disorder (ADHD) is a common disorder of the school-age population. ADHD is familial, and genetic studies estimate heritability at 80%-90%. The aim of the present study was to investigate the association between the genetic type and alleles for the dopamine beta-hydroxylase (DBH) gene in Korean children with ADHD. The sample consisted of 142 ADHD children and 139 control children. We diagnosed ADHD according to DSM-IV. ADHD symptoms were evaluated with the Conners' Parent Rating Scales and Dupaul Parent ADHD Rating Scales. Blood samples were taken from the 281 subjects; DNA was extracted from blood lymphocytes, and polymerase chain reaction was performed for the DBH polymorphism. The alleles and genotype frequencies were compared using the chi-square test. We compared the allele and genotype frequencies of the DBH gene polymorphism in the ADHD and control groups. This study showed that there was a significant correlation among the frequencies of rs1611115 (odds ratio=0.64, 95% confidence interval=0.42-0.97, p=0.034) of the alleles of DBH, but the final conclusions are not definite. Follow-up studies with larger patient or pure subgroups are expected. These results suggested that DBH might be related to ADHD symptoms.

Antisocial personality and bipolar disorder: interactions in impulsivity and course of illness

Antisocial personality disorder (ASPD) and bipolar disorder are both characterized by impulsive behavior, increased incarceration or arrest, addictive disorders and suicidal behavior. These characteristics appear more severe in the combined disorders. Individuals with ASPD who also have bipolar disorder have higher rates of addictive disorders and suicidal behavior and are more impulsive, as measured by questionnaires or behavioral laboratory tests. Those with bipolar disorder who have ASPD have higher rates of addictive, criminal and suicidal behavior, earlier onset of bipolar disorder with a more recurrent and predominately manic course and increased laboratory-measured, but not questionnaire-rated, impulsivity. These characteristics may result in part from differential impulsivity mechanisms in the two disorders, with bipolar disorder driven more by excessive catecholamine sensitivity and ASPD by deficient serotonergic function.

A functional dopamine-beta-hydroxylase gene promoter polymorphism is associated with impulsive personality styles, but not with affective disorders

Dopamine-beta-hydroxylase (DbetaH) catalyzes the conversion of dopamine to norepinephrine in central noradrenergic and adrenergic neurons and thus is critically involved in the biosynthesis of catecholamines. There are equivocal findings concerning the question whether or not DssH activity levels are altered in affective disorders or in subtypes of affective disorders. Moreover, information about the role of dopamine beta-hydroxylase (DBH) genotype, which explains a large part of the variance of enzymatic activity, in affective disorders and personality dimensions is limited. To resolve these inconsistencies, association tests were performed using four independent samples, healthy volunteers (N = 387), patients with affective disorders (N = 182), adult attention deficit hyperactivity disorder (ADHD) patients (N = 407), and patients with personality disorders (N = 637). In the latter two samples, the revised NEO personality inventory (NEO-PI-R) was administered. All participants were genotyped for a putatively functional single nucleotide polymorphism (C-1021T, rs1611115). No differences in DBH C-1021T genotype distribution were observed between patients with affective disorders and healthy control subjects. Also when the patient sample was divided into uni- and bipolar patients versus controls, no significant differences emerged. Furthermore, no clear-cut association was detected between the TT genotype and personality disorder clusters while there was a significant association with adult ADHD. However, personality disorder patients carrying the DBH TT genotype exhibited higher neuroticism and novelty seeking scores as compared to individuals with the CC or CT genotype. Analyses on the level of the neuroticism and novelty seeking subscales revealed that the DBH TT genotype was primarily associated with personality features related to impulsiveness and aggressive hostility. Also adult ADHD patients carrying the homozygous TT genotypes displayed by significantly increased neuroticism scores; when both personality disorder and adult ADHD patient were analyzed together, TT carriers also displayed by significantly lower conscientiousness levels. Our results thus do not implicate the DBH C-1021T polymorphism in the pathophysiology of depressive disorders or personality disorders, yet homozygosity at this locus appears to increase the risk towards personality traits related to impulsiveness, aggression and related disease states, namely adult ADHD. These data argue for a dimensional rather than categorical effect of genetic variance in DBH activity; accordingly, the inconsistency of previous findings concerning DbetaH levels in affective disorders might be caused by the underlying association of the TT genotype at DBH-1021 with impulsive personality traits.

A community-based study of cigarette smoking behavior in relation to variation in three genes involved in dopamine metabolism: Catechol-O-methyltransferase (COMT), dopamine beta-hydroxylase (DBH) and monoamine oxidase-A (MAO-A)

OBJECTIVE

Cigarette smoking behavior may be influenced by catechol-O-methlyltransferase (COMT), dopamine beta-hydroxylase (DBH), and monamine oxidase-A (MAO-A), genes that play roles in dopamine metabolism. The association between common polymorphisms of these genes and smoking behavior was assessed among 10,059 Caucasian volunteers in Washington County, MD in 1989.

METHODS

Age-adjusted logistic regression was used to measure the association between variants of these single nucleotide polymorphisms and smoking initiation and persistent smoking.

RESULTS

Overall, no association was seen between each genotype and smoking behavior. However, among younger (<54 years) women, the COMT GG genotype was positively associated with smoking initiation (OR=1.3; 95% CI: 1.0 1.5), and the MAO-A TT genotype was inversely associated with persistent smoking (OR=0.7; 95% CI: 0.4, 1.0). Men who smoked fewer than 10 cigarettes per day were more likely to be persistent smokers if they had the COMT GG (OR=1.7; 95% CI: 1.0, 2.9) or the DBH GG (OR=1.6; 95% CI: 1.0, 2.5) genotypes.

CONCLUSION

Overall the results of this large community-based study do not provide evidence to support the presence of important associations between variants of COMT, DBH, or MAO-A and smoking initiation or persistent smoking.

Significant impact of MTHFR C677T polymorphism on plasma homovanillic acid (HVA) levels among alcohol-dependent patients

The enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR) synthesizes 5-methyltetrahydrofolate. It plays a critical role in homocysteine metabolism. A high impact of MTHFR C677T polymorphism on plasma homocysteine levels has been observed among alcoholics. Recent studies indicate that homocysteine has toxic effects on dopaminergic neurons. Thus it lowers levels of homovanillic acid (HVA) in the striatal region in rats. Alcoholics had significantly lower plasma HVA concentrations compared with healthy controls. Aim of this study is to elucidate whether HVA plasma levels in alcoholics are influenced by MTHFR C677T polymorphism. A total of 142 alcohol-dependent patients and 101 healthy controls were examined regarding plasma HVA concentration and MTHFR C677T genotype. Blood samples of alcoholics were obtained after a minimum of 22 days of abstinence. Among alcohol-dependent patients MTHFR C677T polymorphism was significantly associated with plasma HVA levels: carriers of MTHFR C677T T-allele had significantly lower HVA plasma levels compared with homozygote carriers of C-allele: 11.9 ng/ml versus 14.4 ng/ml (chi2: 5.39; P = 0.02). In healthy control subjects plasma HVA levels did not differ significantly between MTHFR C677T T-allele carriers and homozygote carriers of C-allele: 15.1 ng/ml versus 15.3 ng/ml (chi2: 0.04; P = 0.82). The data suggest an influence of MTHFR C677T polymorphism on plasma HVA among alcohol-dependent patients. This might be due to neurotoxic effects of homocysteine on the dopaminergic system or direct impairment of monoamine metabolism. Future studies should try to elucidate whether this effect is reversible during alcohol abstinence.

Determination of homovanillic acid (HVA) in human plasma by HPLC with coulometric detection and a new SPE procedure

A sensitive high-performance liquid chromatographic method has been developed for the determination of homovanillic acid (HVA), the main metabolite of dopamine, in human plasma. Analyses were carried out on a reversed-phase column (C8, 250 mm x 4.6 mm i.d., 5 microm) using a mobile phase composed of 10% methanol and 90% aqueous citrate buffer, containing octanesulfonic acid and EDTA at pH 4.8. Coulometric detection was used, setting the guard cell at +0.100 V, the first analytical cell at -0.200 V and the second analytical cell at +0.500 V. A careful solid-phase extraction procedure, based on strong anion exchange (SAX) cartridges (100 mg, 1 mL), was implemented for the pre-treatment of plasma samples. Extraction yield was satisfactory, being the mean value 98.0%. The calibration curve was linear over the concentration range of 0.2-25.0 ng mL(-1) of homovanillic acid. The limit of quantitation (LOQ) was 0.2 ng mL(-1) and the limit of detection (LOD) was 0.1 ng mL(-1). The method was successfully applied to plasma samples from former alcohol, cocaine and heroin addicts. Results were satisfactory in terms of precision and accuracy. Hence, the method is suitable for the determination of homovanillic acid in human plasma.

Association of Antisocial Personality Disorder with Psychiatric Morbidity Among Patients with Substance Use Disorder

OBJECTIVES

The aims were to determine among patients with Substance Use Disorder (SUD) whether patients with Antisocial Personality Disorder (ASPD) manifest less, the same, or more of the following: (1) psychiatric symptoms, (2) family history of psychiatric disorder, (3) psychiatric disorders and morbidity, and (4) psychiatric treatment, as compared to patients without ASPD.

DESIGN & DEFINITION

Scheduled interview using DSM-III-R criteria for ASPD, with blinded interviewers making the ASPD classification vs. other assessments.

SETTINGS

Alcohol-drug treatment programs located in two university medical centers.

SUBJECTS

Six hundred and six voluntary patients aged 18 and older meeting diagnostic criteria for SUD.

RESULTS

SUD patients with ASPD reported more family history of non-SUD psychiatric diagnoses and endorsed more hostility symptoms. Demographic characteristics, psychiatric disorder, and past psychiatric treatment did not differ in association with ASPD.

Brain perfusion SPECT in impulsivity-related personality disorders

BACKGROUND

Impulsive behaviours in patients with cluster B personality disorders are associated with low glucose metabolism and regional cerebral blood flow in the frontal cortex and subcortical structures. The aim of this study is to confirm the presence of a particular pattern of brain perfusion in a sample of borderline (BPD) and anti-social personality disorder (ASPD) patients using brain perfusion single photon emission computed tomography (SPECT).

METHODS

A brain perfusion SPECT study was performed in 37 patients with BPD or ASPD (and no Axis I diagnosis) and 34 healthy control participants. Data were acquired on a triple head Toshiba gamma camera. Scatter and attenuation correction was done. Reconstructed SPECT images were analyzed by Statistical Parametrical Mapping (SPM99).

RESULTS

There were no significant differences in age and gender distributions between the patients and the healthy controls. With regard to the functional imaging results, patients were characterized by a reduced regional cerebral blood flow (rCBF) in right temporal and prefrontal brain areas, including the right lateral temporal cortex (BA 21), the right frontopolar cortex (BA 10) and the right ventrolateral prefontal cortex (BA 47).

CONCLUSIONS

Patients with BPD and ASPD who showed impulsive behaviour have diminished rCBF in areas of the right prefrontal and temporal cortex.

Gene-environment interplay in alcoholism and other substance abuse disorders: expressions of heritability and factors influencing vulnerability

Factors that confer predisposition and vulnerability for alcoholism and other substance abuse disorders may be described usefully within the gene-environment interplay framework. Thus, it is postulated that heritability provides a major contribution not only to alcohol but also to other substances of abuse. Studies of evoked potential amplitude reduction have provided a highly suitable and testable method for the assessment of both environmentally-determined and heritable characteristics pertaining to substance use and dependence. The different personal attributes that may co-exist with parental influence or exist in a shared, monozygotic relationship contribute to the final expression of addiction. In this connection, it appears that personality disorders are highly prevalent co-morbid conditions among addicted individuals, and, this co-morbidity is likely to be accounted for by multiple complex etiological relationships, not least in adolescent individuals. Co-morbidity associated with deficient executive functioning may be observed too in alcohol-related aggressiveness and crimes of violence. The successful intervention into alcohol dependence and craving brought about by baclofen in both human and animal studies elucidates glutamatergic mechanisms in alcoholism whereas the role of the dopamine transporter, in conjunction with both the noradrenergic and serotonergic transporters, are implicated in cocaine dependence and craving. The role of the cannabinoids in ontogeny through an influence upon the expression of key genes for the development of neurotransmitter systems must be considered. Finally, the particular form of behaviour/characteristic outcome due to childhood circumstance may lie with biological, gene-based determinants, for example individual characteristics of monoamine oxidase (MAO) activity levels, thereby rendering simple predictive measures both redundant and misguiding.

Hypothalamic-pituitary-adrenal axis responses to stress in subjects with 3,4-methylenedioxy-methamphetamine ('ecstasy') use history: correlation with dopamine receptor sensitivity

Fifteen 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') users who did not have other drug dependencies or prolonged alcohol abuse and 15 control subjects were studied. All the subjects were exposed to the same psychosocial stressor (Stroop Color-Word Interference Task, public speaking and mental arithmetic in front of an audience) 3 weeks after MDMA discontinuation. Plasma concentrations of adrenocorticotropic hormone (ACTH) and cortisol were measured immediately before the tests began and at their end, 30 min later. Growth hormone (GH) responses to the dopaminergic agonist bromocriptine and psychometric measures (Tridimensional Personality Questionnaire, Minnesota Multiphasic Personality Inventory, Buss-Durkee Hostility Inventory) were also obtained 4 weeks after MDMA discontinuation for the same subjects. ACTH and cortisol basal levels were significantly higher in ecstasy users than in control subjects. In contrast, ACTH and cortisol responses to stress were significantly blunted in MDMA users. The sensitivity of dopamine D2 receptors, reflected by GH responses to bromocriptine challenge, was reduced in MDMA users compared with controls. The responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis (ACTH and cortisol delta peaks) correlated directly with GH areas under curves in response to bromocriptine, and inversely with psychometric measures of aggressiveness and novelty seeking. No correlation was found between hormonal measures and the extent of MDMA exposure. Reduced D2 receptor sensitivity, HPA basal hyperactivation and reduced responsiveness to stress may represent a complex neuroendocrine dysfunction associated with MDMA use. The present findings do not exclude the possibility that dopamine dysfunction partly predated MDMA exposure.

Plasma homovanillic acid: a significant association with alcoholism is independent of a functional polymorphism of the human catechol-O-methyltransferase gene

The central dopamine system seems to influence addictive disorders. Plasma homovanillic acid (HVA) is an indicator of central dopaminergic activity. In this study the hypothesis that plasma HVA is associated with alcoholism or with delirium tremens (DT) during alcohol withdrawal was tested. A functional genetic polymorphism of the enzyme catechol-O-methyltransferase (COMT) that participates in converting dopamine into its final metabolite HVA was investigated for an association with alcoholism or DT during alcohol withdrawal. In addition, a relation between the functional polymorphism of COMT and plasma HVA concentrations was studied. Plasma HVA concentrations and COMT genotypes were determined in 142 German alcoholics and 101 German healthy controls. Alcoholic patients were examined after a minimum of 3 weeks after cessation of drinking. Mean plasma HVA concentrations were significantly lower in alcoholic patients compared to healthy controls. A group of alcoholics with a history of DT during alcohol withdrawal (n=62) did not differ significantly in plasma HVA concentrations from alcoholics with a history of only mild withdrawal symptoms (n=67). The functional polymorphism of the human COMT gene was neither significantly associated with the diagnosis of alcoholism or DT during alcohol withdrawal nor with plasma HVA concentrations.

Effects of (+/-) 3,4-methylene-dioxymethamphetamine (ecstasy) on dopamine system function in humans

Twelve (+/-) 3,4-methylenedioxymethamphetamine (MDMA) users, who did not show other drug dependencies or prolonged alcohol abuse (group A), and 12 control subjects (group B) were included in the study. Prolactin (PRL) and growth hormone (GH) responses to the dopaminergic agonist bromocriptine (BROM) and psychometric measures were evaluated 3 weeks after MDMA discontinuation. PRL decreased both in A and B subjects after BROM suppression, without any significant difference between the two groups. PRL responses to BROM in MDMA users were in the normal range. In contrast, GH responses to BROM stimulation were found significantly reduced in ecstasy users, in comparison with control subjects (P < 0.001; F = 6.26). MDMA users showed higher scores on the Novelty Seeking (NS) scale at the Three dimensional Personality Questionnaire (TPQ), on direct aggressiveness subscale at Buss Durkee Hostility Inventory (BDHI), on subscale D (depression) at Minnesota Multiphasic Personality Inventory (MMPI 2) and on Hamilton Depression Rating Scale (HDRS) than control subjects. PRL areas under the curves (AUCs) showed a significant inverse correlation with NS scores both in A and B subjects. GH AUCs directly correlated with NS scores in healthy subjects, but not in MDMA users. No other psychometric measure correlated with hormonal responses. GH AUCs were inversely correlated with the measures of MDMA exposure (r = -0.48; P < 0.01). Lower GH response to BROM in A subjects (MDMA users) could reflect reduced D2 receptor sensitivity in the hypothalamus, possibly due to increased intrasynaptic dopamine concentration. Although the hypothesis of dopaminergic changes associated with a premorbid condition cannot be completely excluded, the inverse correlation between DA receptors sensitivity and the extent of ecstasy exposure may suggest a direct pharmacological action of MDMA on brain dopamine function in humans.

Association between polymorphisms in dopamine metabolic enzymes and tobacco consumption in smokers

Central dopaminergic reward pathways give rise to dependence and are activated by nicotine. Allelic variants in genes involved in dopamine metabolism may therefore influence the amount of tobacco consumed by smokers. We developed assays for polymorphisms in dopamine beta-hydroxylase (DBH), monoamine oxidase (MAO) and catechol O-methyl transferase (COMT) using the polymerase chain reaction with sequence specific primers (PCR-SSP). We then typed 225 cigarette smokers to assess whether genotype was related to the number of cigarettes smoked a day. Smokers with DBH 1368 GG genotype smoked fewer cigarettes than those with GA/AA [mean difference -2.9 cigarettes, 95% confidence interval (CI) -5.5, -0.4; P = 0.022]. The effect reached statistical significance in women (-3.8, 95% CI -6.4, -1.0, P = 0.007) but not in men (-1.5, 95% CI -6.0, 3.0, P = 0.498). Overall, the effect was greater when analysis was confined to Caucasians (-3.8, 95% CI -6.6, -1.1, P = 0.007). Smokers with MAO-A 1460 TT/TO smoked more cigarettes than those with CC/CT/CO (2.9, 95% CI 0.6, 5.1, P = 0.013). Within each sex group, the trend was similar but not statistically significant (difference for men 2.9, 95% CI -1.0, 6.7; for women 2.0, 95% CI -0.7, 4.8). The effect of the allele was greater in smokers with a high body mass index (> 26) (difference 5.1, 95% CI 1.4, 8.8, P = 0.008). More heavy smokers (> 20 a day) had the DBH 1368A allele when compared to light smokers (< 10 a day). (Relative risk 2.3, 95% CI 1.1, 5.0, P = 0.024.) The trend for increasing prevalence of the DBH A allele in heavy smokers was greater when analysis was restricted to Caucasians (relative risk 3.2, 95% CI 1.3, 8.2, P = 0.004). Conversely, heavy smokers were less likely to have the MAO-A 1460C allele (relative risk 0.3, 95% CI 0.1, 0.7, P = 0.012). Variations in DBH and MAO predict whether a person is a heavy smoker and how many cigarettes they consume. Our results support the view that these enzymes help to determine a smoker's requirement for nicotine and may explain why some people are predisposed to tobacco addiction and why some find it very difficult to stop smoking. This finding has important implications for smoking prevention and offers potential for developing patient-specific therapy for smoking cessation.

A review of the effects of moderate alcohol intake on psychiatric and sleep disorders

In this chapter we discuss the effects of moderate ethanol consumption on the treatment of psychiatric and sleep disorders. A review of the literature on the interactions of ethanol with neurotransmitters and psychotropic medications suggests that although ethanol affects the clinical course of psychiatric and sleep disorders by different mechanisms, it does so principally through perturbations it causes in the balance of central nervous system neurotransmitter systems, which may modify the clinical course of primary psychiatric and sleep disorders and undermine the therapeutic response to psychotropic medications. Neurotransmitter responses may also be manifested clinically by rebound phenomena, akin to a subsyndromal withdrawal, which affect sleep and precipitate anxiety and mood symptoms. In addition, ethanol also modifies the clearance and disposition of a variety of psychotropic metabolites and interferes with their clinical effectiveness. We recommend that most psychiatric patients, and all patients with sleep disorders, should abstain from even moderate ethanol use, as this may adversely affect their clinical course and response to treatment.