Plasma homovanillic acid levels and subtyping of schizophrenia

Assessment of psychiatric and behavioral adverse effects of antiepileptic drugs monotherapy: Could they have a neuroendocrine correlation in persons with epilepsy?

OBJECTIVE

The study investigated overall adverse event (AE) burden and specifically psychiatric and behavioral side effects (PBAEs) in persons with epilepsy (PWE) on antiepileptic drugs (AEDs) monotherapy. It also assessed their correlation with neuroendocrine and oxidative stress biomarkers.

METHODS

This cross-sectional observational study was conducted at a tertiary care hospital between 2016 and 2018. Persons with epilepsy above 18 years on monotherapy of levetiracetam (LEV) and conventional AEDs {carbamazepine (CBZ), phenytoin (PHT), or valproate (VPA)} for at least 6 months were enrolled. Validated questionnaires, 'Mini-International Neuropsychiatric Interview (MINI 7.02)', 'Depression, Anxiety, and Stress Scale 21 (DASS-21)', 'Buss-Perry Aggression Questionnaire (BPAQ)', 'patient-weighted Quality of life Index in Epilepsy (QOLIE-10)', 'Pittsburgh Sleep Quality Index (PSQI)', and 'Liverpool Adverse Events Profile (LAEP)' were used to assess the PBAEs, quality of life, sleep quality, and AE profile. A subgroup of PWE recruited consecutively were considered for estimation of the following neuroendocrine biomarker levels: brain-derived neurotrophic factor (BDNF), homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and total antioxidant capacity (TAC) which were then correlated with scores of above questionnaires.

RESULTS

After screening 220 PWE, 163 PWE (58 on LEV and 105 on conventional AEDs) with a mean age of 29 ± 10 years were enrolled. Mini-International Neuropsychiatric Interview revealed that LEV group had higher association with PBAEs and lower quality of sleep compared to conventional AEDs (p = 0.032 and 0.046, respectively). Other scales did not show significant difference between LEV and conventional AEDs. In the subset of PWE (n = 74, 36 on LEV and 38 on conventional AEDs), LEV group had more association with the PBAEs (p = 0.010), higher physical aggression and anger components of BPAQ (p = 0.03 and 0.02, respectively), and more AE (p = 0.049) than conventional AED group. However, there was no significant difference in neuroendocrine biomarker levels.

CONCLUSION

Levetiracetam had a higher association with PBAEs and more AE when compared to conventional AEDs. There was no differential correlation of AEDs with the following neuroendocrine markers: BDNF, HVA, 5-HIAA, and TAC. These facts necessitate exploration of other mechanisms for LEV-induced PBAEs.

Antidopaminergic medication in healthy subjects provokes subjective and objective mental impairments tightly correlated with perturbation of biogenic monoamine metabolism and prolactin secretion

OBJECTIVES

Off-label prescription of antipsychotics to patients without psychotic symptoms has become a routine matter for many psychiatrists and also some general practitioners. Nonetheless, little is known about the possibly detrimental effects of antidopaminergic medications on general psychopathology, subjective mental state, or a possible association with physiological parameters in nonpsychotic individuals.

METHODS

In this randomized, single-blinded study, groups of healthy volunteers (n=18) received low doses of reserpine, aripiprazole, haloperidol, or placebo on 7 successive days. Relevant physiological parameters (plasma prolactin, concentrations of catecholamine metabolites in plasma, and 24-hour urine) and each subject's mental state (Positive and Negative Syndrome Scale, Hamilton Rating Scale for Depression, visual analogue scale, Beck Depression Inventory II) were assessed at the start and end of the trial.

RESULTS

Of the three active treatments, only reserpine caused a significant increase in some plasma- and urine-catecholamine metabolites, but all three medications evoked objective and subjective changes in general psychopathology scores, which correlated with individual increases in plasma homovanillic acid concentrations. Both objective and subjective impairments were significantly more pronounced in the subgroup with greatest increase of plasma prolactin. Subjects experiencing the most pronounced side effects under haloperidol, which compelled them to drop out, showed significantly higher prolactin concentration increases than those who tolerated haloperidol well.

CONCLUSION

We found consistent associations between altered markers of dopamine transmission and several objective and subjective mental impairments in healthy volunteers after 1 week's treatment with antidopaminergic medications. These findings should draw attention to a more intensive risk-benefit evaluation in cases of off-label prescription of antipsychotic medications.

Effects of D-cycloserine on negative symptoms in schizophrenia

INTRODUCTION

The negative and cognitive symptoms of schizophrenia are poorly responsive to neuroleptic treatment. Glutamatergic dysfunction may mediate some of these symptoms. Low dose D-cycloserine (DCS) is a partial agonist at the glycine site of the NMDA-associated receptor complex, noncompetitively enhancing NMDA neurotransmission. Prior studies suggest a beneficial effect of DCS on negative symptoms and cognition. This treatment trial was initiated to confirm and extend these findings.

METHODS

Twenty-two male schizophrenic subjects displaying prominent negative symptoms who were stabilized on typical neuroleptics completed the study. A randomized double-blind parallel group design was used to compare the effects of 50 mg p.o. QD of DCS to placebo over 4 weeks. The two subject groups did not differ significantly in age, age of onset of illness or time on current neuroleptic treatment. Symptoms were rated by means of the SANS, BPRS and Abrams and Taylor rating scale. Cognition was assessed with the Sternberg Memory Test and the Continuous Performance Test.

RESULTS

Both medication groups improved over the 4 weeks of treatment. However, there were no significant differences between the DCS and placebo group on any symptom rating. DCS effects on cognition did not differ from placebo.

DISCUSSION

This study did not detect improvement in negative symptoms or cognitive performance with DCS treatment that has been found in some prior studies. This negative finding may be attributed to small sample size, relatively short duration of treatment and the overall modest effect of DCS. Future studies of DCS should be adequately powered to detect a small to medium effect size and should provide for a longer treatment phase than was used in this study in order to avoid a type II error.

Subchronic haloperidol downregulates dopamine synthesis capacity in the brain of schizophrenic patients in vivo

The antipsychotic effect of neuroleptics cannot be attributed entirely to acute blockade of postsynaptic D(2)-like dopamine (DA) receptors, but may arise in conjunction with the delayed depolarization block of the presynaptic neurons and reduced DA synthesis capacity. Whereas the phenomenon of depolarization block is well established in animals, it is unknown if a similar phenomenon occurs in humans treated with neuroleptics. We hypothesized that haloperidol treatment should result in decreased DA synthesis capacity. We used 6-[(18)F]fluoro-L-dopa (FDOPA) and positron emission tomography (PET) in conjunction with compartmental modeling to measure the relative activity of DOPA decarboxylase (DDC) (k(D)(3), min(-1)) in the brain of nine unmedicated patients with schizophrenia, first in the untreated condition and again after treatment with haloperidol. Patients were administered psychometric rating scales at baseline and after treatment. Consistent with our hypothesis, there was a 25% decrease in the magnitude of k(D)(3) in both caudate and putamen following 5 weeks of haloperidol therapy. In addition, the magnitudes of k(D)(3) in cerebral cortex and thalamus were also decreased. Psychopathology as measured with standard rating scales improved significantly in all patients. The decrease of k(D)(3) in the thalamus was highly significantly correlated with the improvement of negative symptoms. Subchronic treatment with haloperidol decreased the activity of DDC in the brain of patients with schizophrenia. This observation is consistent with the hypothesis that the antipsychotic effect of chronic neuroleptic treatment is associated with a decrease in DA synthesis, reflecting a depolarization block of presynaptic DA neurons. We link an alteration in cerebral catecholamine metabolism in human brain with the therapeutic action of neuroleptic medication.

Pretreatment plasma HVA and haloperidol response in acute mania

INTRODUCTION

Pretreatment plasma homovanillic acid (HVA) levels have been reported to be a correlate of clinical response to typical antipsychotics for schizophrenic, bipolar manic, and mixed groups of psychotic patients. Biological markers of clinical response to antipsychotics could be useful for optimizing drug treatment.

METHOD

Thirty-one consenting acute inpatient subjects between ages 19 and 66 years with a DSM-III-R clinical diagnosis of bipolar disorder, manic with psychotic features were entered into this double-blind study and were randomly assigned to receive either haloperidol 25 mg/day or haloperidol 5 mg for the 3-week study. Subjects also received one of the following concomitant medications: standard lithium, lorazepam 4 mg/day, or placebo.

RESULTS

The primary multiple regression analysis, including all subjects on both haloperidol doses, yielded a significant main effect for pretreatment plasma HVA (n=31, F=5.7, P=0.025), indicating that higher pretreatment plasma HVA was predictive of better clinical response. In addition, the interaction between haloperidol dose and pretreatment plasma HVA was also significantly associated with clinical response (F=12.59, P=0.0015). When the two haloperidol doses were analyzed separately, we found that pretreatment plasma HVA was only correlated with clinical response in the low haloperidol 5 mg/day group (n=18, F=11.73, P=0.0038) and was unrelated to clinical response to the high haloperidol 25 mg/day group.

LIMITATIONS

The sample size was small. Results may have been confounded by prior antipsychotic treatment and concomitant use of lithium or lorazepam.

DISCUSSION

These results suggest that pretreatment plasma HVA could be useful for dosing antipsychotics. Patients with high plasma HVA levels would be good candidates for low-dose treatment because they are more likely to improve on such a dose, while patients with low plasma HVA levels might warrant more rapid dosage escalation.

Plasma homovanillic acid and the dopamine transporter during cocaine withdrawal

BACKGROUND

Plasma homovanillic acid (HVA) has been used as a measure of central dopaminergic activity but the validity of this method continues to be investigated. We used single photon emission tomography (SPECT) assessment of the dopamine (DA) transporter for comparison with plasma HVA in subjects at varying stages of abstinence from cocaine.

METHODS

Nineteen subjects were studied in two separate treatment sites. Plasma HVA and methoxyhydroxyphenethyleneglycol (MHPG) were measured by gas chromatography-mass spectroscopy (GC-MS). The DA transporter was quantified using the SPECT ligand [123I]B-CIT.

RESULTS

At 2 weeks of abstinence and beyond there was an increasing positive correlation between plasma HVA and the SPECT measurement of the DA transporter (V3").

CONCLUSIONS

Plasma HVA may be more likely to reflect DA transporter density in the striatum when there is not a major drug-related change in the DA system.

Pretreatment plasma HVA predicts neuroleptic response in manic psychosis

Elevated pretreatment plasma free homovanillic acid (HVA) predicted acute response to neuroleptic treatment in patients with manic psychosis. These findings suggest that plasma HVA may be a useful predictor of a successful short-term response in manic as well as schizophrenic psychoses, and that elevated pre-synaptic dopaminergic release may play a role in more than one group of psychotic disorders.

Schizophrenic patients with deficit syndrome have higher plasma homovanillic acid concentrations and ventricular enlargement

In order to investigate the biological characteristics of deficit syndrome in schizophrenia (Carpenter et al 1988), we examined cerebroventricular ratios (CVRs) and plasma concentrations of homovanillic acid (HVA) in a group of schizophrenic inpatients with deficit syndrome (n = 20) and in a control group of age- and sex-matched schizophrenic inpatients without deficit syndrome (n = 20). Symptoms and intelligence levels were measured using the Brief Psychiatric Rating Scale (BPRS) and the Wechsler Adult Intelligence Scale (WAIS), respectively. Patients in the deficit group had significantly higher CVRs as well as significantly elevated plasma HVA concentrations when compared with patients in the nondeficit group. We also found that the mean total WAIS score in the deficit group was significantly lower than that in the nondeficit group. These findings suggest the biological heterogeneity of schizophrenia. Increased central dopaminergic turnover, as indicated by higher plasma HVA concentrations, may partially account for the pathogenesis of deficit syndrome.

Longitudinal changes in symptoms and plasma homovanillic acid levels in chronically medicated schizophrenic patients

A correlation has been noted between the changes in plasma homovanillic acid concentrations and changes in psychiatric symptoms induced by neuroleptic treatment. Our objective was to determine whether plasma homovanillic acid concentration changed in accordance with the changes in symptoms over time. Twenty-eight chronically medicated schizophrenic inpatients received the same treatment regimen for 1 year. Symptoms and plasma homovanillic acid concentrations were examined every month and whenever conditions deteriorated. Plasma homovanillic acid concentrations were significantly higher in the patients in the worst condition than in the patients in the best condition. Further, when comparing the best and worst conditions of both the positive and negative symptoms, the change in psychiatric rating of positive and negative symptoms was correlated significantly with the change in plasma homovanillic acid level. These results suggest that a change in plasma homovanillic acid concentration can be produced not only by neuroleptic-induced dopaminergic blocking but also by a change in positive and negative symptoms of schizophrenia.

Serum fructosamine correlates with gingival index in children with insulin-dependent diabetes mellitus (IDDM)

Fructosamine assay, which is used in diagnosing and monitoring diabetic patients, is compared with the hemoglobin and plasma glucose assays in children and adolescent insulin-dependent diabetes mellitus patients. We demonstrated that the gingival index scores were correlated with fructosamine values in insulin-dependent diabetes mellitus patients but not in non-diabetic controls. We also found that there was no correlation between gingivitis scores and fasting plasma glucose and HbA1c values. Periodontitis was found to be rare in diabetic children and adolescents.

Tetracyclines inhibit Porphyromonas gingivalis-induced alveolar bone loss in rats by a non-antimicrobial mechanism

Tetracyclines have been widely used as adjuncts in periodontal therapy due to the antimicrobial efficacy of these drugs. Recently, their ability to inhibit host-derived matrix metalloproteinases (collagenase and gelatinase) and bone resorption in organ culture has also been invoked as a therapeutic rationale. The current study was undertaken to determine whether tetracyclines can inhibit alveolar bone loss in vivo due to a non-antimicrobial action of these drugs. Experimental periodontitis was induced by inoculating adult, male Sprague-Dawley rats with P. gingivalis (strain 381) following kanamycin/ampicillin pretreatment. Doxycycline, non-antimicrobial chemically-modified tetracycline (CMT-1) and vehicle alone were administered daily to 3 infected groups of rats (n = 6 rats per group; each group housed in a sterilized inflatable isolator) beginning 10 days after P. gingivalis inoculation. The control group (n = 6; non-infected rats) received only vehicle. After 5 weeks of daily drug administration by gastric intubation, the experiment was terminated and blood samples were taken from each animal to determine antibody levels against P. gingivalis. Plaque samples were collected from each group of animals before and after P. gingivalis inoculation and at the end of the experiment for microbiological examination. The jaws were removed from each rat, defleshed and then analyzed morphometrically and radiographically to assess bone loss. Serum antibody levels against P. gingivalis were significantly elevated in the 3 infected groups compared to the non-infected controls. This, together with the microbiologic findings, indicated that these groups of rats were infected with P. gingivalis.(ABSTRACT TRUNCATED AT 250 WORDS)

Monoamine activity reflected in urine of young patients with obsessive compulsive disorder, psychosis with and without reality distortion and healthy subjects: an explorative analysis

Positive psychotic symptoms are reported to be associated with high, negative symptoms with low dopamine (DA) activity and serotonin (5HT) activity may be altered in obsessive-compulsive disorder (OCD). We analysed 24 h urine samples in these patient groups and in healthy controls for supportive evidence. Young unmedicated OCD subjects excreted more adrenaline (AD) and homovanillic acid (HVA) and showed a higher HVA/MHPG ratio and metabolic rate than healthy controls. Independent of general metabolic rate they showed higher HVA concentrations which suggests that the relative activity of catecholamine systems in OCD (HVA/MHPG) is due more to high DA than to low noradrenergic (NA) activity. Concentrations of 5HT were also high in OCD patients. In psychotic patients low levels of DA, HVA, NA and MHPG probably resulted from neuroleptic medication. Patients diagnosed with paranoid psychosis showed higher DA utilization than controls and those with few paranoid symptoms showed high 5HT utilization. These results support studies suggesting that paranoid psychosis is associated more with increased DA activity (discussed in the context of neuroleptic reactivity), that non-paranoid forms are associated more with increased 5HT activity and that OCD patients are unusually aroused with high levels of Ad, 5HT and HVA.

Persistent psychosis after reduction in pre- and post-synaptic dopaminergic function

The purpose of this study was to evaluate the hypothesis that neuroleptic non-response in the face of "adequate" DA post-synaptic receptor blockade reflects failure of regulatory mechanisms to decrease DA pre-synaptic activity. Eight chronic schizophrenics, meeting rigorous criteria for neuroleptic non-response, were treated for four weeks with alpha-methylparatyrosine as an adjunct to their previously stable neuroleptic dose. Treatment with AMPT produced a prompt decrease in plasma HVA that was, on average, 72% lower at the end of the study. While there was also strong clinical evidence of reduction in central dopaminergic activity (both a significant reduction in dyskinetic movements and increase in extrapyramidal symptoms), there was virtually no change in severity of psychotic symptoms. Thus, in this group of non-responders, psychotic symptoms persisted despite both extensive dopamine post-synaptic receptor blockade and marked reduction of presynaptic activity. These symptoms may not be directly DA dependent.

Increased serum IgE in schizophrenic patients who responded poorly to neuroleptic treatment

Total serum IgE and plasma Interleukin (IL)-4 have been determined in patients with schizophrenia, 26 neuroleptic-free, and 81 neuroleptic-treated, and in 46 healthy control subjects. The total serum IgE was significantly higher in the patients who responded poorly to neuroleptic treatment compared with the other four groups (F = 4.27, df = 4, 148, P < 0.003). No significant changes were found in plasma IL-4 levels between any of the five groups. It is possible that raised serum IgE levels may characterise a subgroup of schizophrenia.

Plasma homovanillic acid in neuroleptic responsive and nonresponsive schizophrenics

Changes in plasma homovanillic acid (HVA) were investigated in neuroleptic responsive and nonresponsive schizophrenics in order to delineate parameters of dopamine regulation, which may underlie differences in neuroleptic responsivity. Nineteen schizophrenics were treated with haloperidol for 6 weeks. HVA was sampled at baseline, 24 hr after initial neuroleptic dose, and after 6 weeks of treatment. Subjects were pretreated with debrisoquin in order to reduce the peripheral production of HVA. The responders had an initial rise in HVA at 24 hr after first neuroleptic dose, followed by a decline back to baseline over the 6 weeks of treatment. The nonresponders' HVA failed to rise at 24 hr after first neuroleptic dose. At 6 weeks of treatment their HVA had fallen to significantly below baseline. Thus, a rise in HVA 24 hr after the first dose of neuroleptic predicted treatment response; a fall in HVA at 6 weeks to below pretreatment values was associated with neuroleptic nonresponse.

Rapid and reliable high-performance liquid chromatographic method for analysing human plasma serotonin, 5-hydroxyindoleacetic acid, homovanillic acid and 3,4-dihydroxyphenylacetic acid

The simultaneous measurement of homovanillic acid, 3,4-dihydroxyphenylacetic acid, serotonin and 5-hydroxyindoleacetic acid in human plasma by an ultrafiltration and microbore high-performance liquid chromatography-electrochemical detection technique is established. Conventional preparation of blood is very tedious and time-consuming, but isocratic separation of the analytes in plasma ultrafiltrates using a microbore column could be achieved within 10 min. Hence, theoretically, over 140 analyses can be performed in a working day. The detection limit (signal-to-noise ratio = 3) of this method is about 0.1-0.5 pg per injection for all analytes. The required volume of plasma samples can be less than 100 microliters. Hence, blood loss is minimal, especially in repeated blood sampling. This rapid, simple and sensitive method can, therefore, be used as a routine clinical tool in the simultaneous measurement of plasma homovanillic acid, 3,4-dihydroxyphenylacetic acid, serotonin and 5-hydroxyindoleacetic acid.

Serum homovanillic acid levels in schizophrenic patients and normal control subjects

Schizophrenic patients with an early age at onset of illness had low baseline levels of homovanillic acid (HVA) in serum compared with schizophrenic patients with a late age at onset. After adjustments were made for age at onset, there was a significant partial correlation between positive symptoms and serum HVA. The relationship between positive symptom scores and serum HVA was shifted to the left in the early onset patients, suggesting a relatively increased sensitivity of dopamine-associated response. Patients with severe negative symptoms also had an earlier age at onset and a trend toward lower serum HVA. This study found no difference between mean serum HVA values in schizophrenic patients and normal control subjects.

Studies on neurochemical heterogeneity in healthy parents of schizophrenic patients

Serum homovanillic acid (HVA), norepinephrine (NE), phenylalanine (Phe) and tyrosine (Tyr) have been examined in 80 healthy parents of schizophrenic patients and 26 normal control subject. Analysis of variance revealed a significant difference in serum HVA concentration among the three groups: the parents whose ill offspring became fairly well after neuroleptic treatment for more than three months (n = 33), those whose offspring were still actively ill after neuroleptic treatment (n = 33), and normal control subjects (F = 3.98, df = 2, 89, p < 0.05). The t-test showed that serum HVA was significantly higher in the parents whose ill offspring became fairly well after neuroleptic treatment (11.8 +/- 5.0 ng/ml) than in normal control subjects (8.7 +/- 3.5 ng/ml, p < 0.01), but was not significantly higher in the parents whose offspring were still actively ill (10.5 +/- 3.7 ng/ml, p > 0.05). There was a significant difference between the serum NE concentrations of the parents of female patients (515 +/- 224 pg/ml, n = 21) and those of male patients (401 +/- 186 pg/ml, n = 55, p < 0.05). No significant differences were found in the serum concentrations of Phe and Tyr. These results suggest that there may be neurochemical heterogeneity in the parents of schizophrenic patients, which may be involved in the response of schizophrenic offspring to neuroleptic treatment and in the gender differences of schizophrenia.

Effects of single dose haloperidol administration on plasma homovanillic acid levels in normal subjects

Homovanillic acid (HVA), an oxidative metabolite of dopamine, has been shown in a number of studies to reflect severity of symptoms and to predict response to neuroleptic treatment in schizophrenic patients. In several clinical studies, HVA levels have been shown to have a positive relationship with symptom severity and to decline over time upon treatment with antipsychotic agents. The magnitude of this decline appears to be related to the degree of symptom reduction in patients so treated. However, administration of dopamine postsynaptic antagonists should be expected to increase synaptic dopamine availability, thereby increasing HVA concentrations, according to traditional models of drug action. While in some studies, this appears to be the case, we saw no evidence of an early phase of HVA elevation after administration of 4- and 10-milligram doses of haloperidol to human volunteers. Rather, HVA levels declined during the period of absorption and attainment of peak haloperidol levels. Baseline HVA levels of 51.6 +/- 3.83 pmoles/ml and 56.8 +/- 5.70 pmoles/ml (after 4 mg and 10 mg., respectively) declined to minima of 35.6 +/- 1.67 pmoles/ml and 26.3 +/- 5.34 pmoles/ml respectively, at 3-4 hours after haloperidol administration. A trend was noted for the 10-mg dose to produce a greater decline than the 4-mg dose, which was most apparent at 4 hours after drug administration. The shape of both curves did not appear to be substantially different than expected on the basis of diurnal variation. These preliminary findings support the concept that dopamine turnover in humans is not increased and may be decreased by short-term administration of conventional neuroleptics.

Periodontal bone loss in Porphyromonas gingivalis-infected specific pathogen-free rats after preinoculation with endogenous Streptococcus sanguis

Anaerobic Gram-negative bacteria dominate in periodontitis locations, while Gram-positive bacteria characterize healthy sites. A well-established Gram-positive flora might therefore inhibit the colonization of Gram-negative pathogens. The purpose of the present investigation was to examine whether endogenous S. sanguis could prevent, or reduce, periodontal bone loss in rats infected with a virulent P. gingivalis strain. Sixty specific pathogen-free Wistar rats were divided into 6 groups. Doxycycline was administered in the drinking water for 2 weeks to the groups A, B, C, and D to suppress the preexisting microflora in the mouth. Rats in groups A and C were subsequently inoculated with an S. sanguis strain, isolated from one of the rats, once a day for 5 d. Infection with P. gingivalis 381 was then carried out for 5 d in groups A, B, and E. Group F was not treated with doxycycline nor infected with bacteria and served as untreated control. Six weeks after the P. gingivalis inoculation, the rats were killed. Periodontal bone levels were assessed radiographically and morphometrically, and serum antibody against P. gingivalis 381 was determined by a fluorescence immunoassay. Periodontal bone support, determined radiographically, was reduced in group B (doxycycline-treated, P. gingivalis-inoculated) compared with the other groups. In contrast, the morphometric determination showed no differences between the groups. In group B antibody levels against two different P. gingivalis 381 cell surface antigens were significantly elevated.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma homovanillic acid, plasma anti-D1 and -D2 dopamine-receptor activity, and negative symptoms in chronically mediated schizophrenia

We have investigated the relationship between the concentration of homovanillic acid in human plasma (pHVA) and plasma anti-D1 and anti-D2 dopamine receptor activity in chronic schizophrenic patients whose neuroleptic dosage was changed. The change in pHVA level correlated with that in anti-D1, not anti-D2 activity, thus suggesting that the neuroleptic-induced changes in pHVA concentration may be associated with the blocking of D1- as well as D2- receptors. The change of scores on the Scale for the Assessment of Negative Symptoms did not significantly correlate with changes in anti-D1 or anti-D2 activity, but did so correlated with the change in pHVA level.

The biochemical basis of relapse and drug response in schizophrenia: review and hypothesis

This review of the literature suggests that antipsychotic drug response is determined by dopamine (DA) turnover and norepinephrine (NE) activity prior to treatment. The data suggest that NE modulates the DA system. Drug-free psychotic patients with relatively increased DA and NE activity, including release, are more likely to be treatment responsive, while patients who show evidence of enhanced DA and NE activity during treatment with antipsychotic drugs are likely to relapse soon after neuroleptic withdrawal. Basal release of DA and NE is decreased and associated with residual positive and negative symptoms. Improvement during neuroleptic treatment is associated with decreases in DA and NE phasic or stimulus induced release. The variable response to antipsychotic drugs is most likely to be a result of dysregulated DA and NE release, i.e. under state-dependent control, rather than evidence of a heterogeneous aetiology. Because catecholamines regulate gain, signal-to-noise ratio and gating in the brain, this model allows for environmental factors to interact with biochemical state and drug treatment. The author proposes that impaired homeostasis of NE and DA in schizophrenia causes instability in NE and DA neuronal firing and release, presumably related to mechanisms down-stream from the receptors, such as G proteins. This instability of catecholamine release may explain the observed variability in clinical states and drug response in schizophrenia.

Plasma free homovanillic acid (HVA) as a predictor of clinical response in acute psychosis

The relationship of plasma free homovanillic acid (HVA) and methoxyhydroxyphenylglycol (MHPG) to early clinical response was prospectively studied in a new series of acutely psychotic inpatients given a fixed dose of perphenazine elixir for 10 days. Elevated pretreatment plasma HVA but not MHPG was significantly associated with good response. Change in HVA was correlated with a favorable response and a significant decline in MHPG was found in responders. Results suggest that HVA can provide a useful clinical predictor of response, and that both dopamine metabolism and noradrenergic functioning, as measured by plasma HVA and MHPG, are reduced in effective neuroleptic treatment.

Periodontal bone level and gingival proteinase activity in gnotobiotic rats immunized with Bacteroides gingivalis

Bacteroides gingivalis is associated with various forms of periodontal disease. To assess the role of the immune response in modulating B. gingivalis-associated periodontal disease, the effect of immunization of B. gingivalis-induced periodontal bone loss was evaluated in gnotobiotic rats. Male Sprague-Dawley rats immunized with various doses of whole cells or sham-immunized with incomplete Freund's adjuvant were monoinfected with B. gingivalis in carboxymethylcellulose by gavage. Two additional groups served as either sham-immunized or untreated germ-free controls. Forty-two days after infection, all rats were killed, periodontal bone level was assessed morphometrically and radiographically, and gingival proteinase (mammalian collagenase and acid cathepsin) activity was assessed biochemically. B. gingivalis was present in oral samples from all monoinfected rats, and no contaminating bacteria were detected in any oral or fecal sample. Animals immunized with B. gingivalis cells had elevated serum and saliva antibodies to whole cells and partially purified fimbriae from B. gingivalis. Infected sham-immunized rats had significantly more periodontal bone loss than noninfected controls, whereas the periodontal bone level in infected rats immunized with 10(10) B. gingivalis cells was similar to that of the noninfected controls. The activities of gingival collagenase and cathepsin B and L were high in sham-immunized infected rats and low in all other animal groups. In conclusion, it is possible to reduce B. gingivalis-induced periodontal tissue loss in gnotobiotic rats by immunization.

Dopamine and norepinephrine activity in schizophrenia. An integrative perspective

The dopamine (DA) hypothesis of schizophrenia stated that increased DA activity is the primary cause of schizophrenia. Recently, even though increased DA activity is in fact involved in psychotic symptoms and antipsychotic drug response, it has become clear that decreased DA activity is present in remitted and chronic states and may relate to deficit symptoms and cortical lesions. In addition, the norepinephrine (NE) system seems to be involved in symptomatology, antipsychotic drug response, course, and outcome in schizophrenia. This review supports the hypothesis that a disturbance in DA and NE activity regulates schizophrenic behavior. A plethora of DA- and NE-related findings in schizophrenic patients are reviewed in relationship to each other according to basic science data and to presently entertained hypotheses, with emphasis on a neural developmental disturbance interacting with a genetic predisposition shaped by environmental factors.

Plasma HVA, tardive dyskinesia and psychotic symptoms in long-term drug-free inpatients with schizophrenia

Plasma homovanillic acid (pHVA) levels were measured in 16 chronically ill patients with schizophrenia who also suffered from tardive dyskinesia, and in a group of 14 chronically ill patients with schizophrenia who did not have tardive dyskinesia. All patients were studied following an extensive drug-free period (mean = 32.9 months). Patients with orofacial dyskinesia had significantly lower levels of pHVA than did controls. In patients without tardive dyskinesia, pHVA levels were significantly correlated with both positive and negative symptomatology. In contrast, pHVA levels from patients with tardive dyskinesia bore neither a significant nor a nearly significant relationship to symptomatology. The implications of these findings for dopaminergic models of tardive dyskinesia are discussed.

Plasma catecholamine metabolites in schizophrenics: evidence for the two-subtype concept

Plasma homovanillic acid (pHVA) and plasma methoxyhydroxyphenyl glycol (pMHPG), as well as plasma haloperidol, were measured in 33 schizophrenic patients before and during 6 weeks of haloperidol treatment. Good responders had higher baseline pHVA values compared with poor responders (17.4 +/- 8.8 ng/ml, n = 22 versus 11.4 +/- 5.0 ng/ml, n = 11, p less than 0.05). A higher than 15 ng/ml pretreatment pHVA level was associated with a more consistent clinical response to the subsequent treatment. Differential pHVA changes during treatment were also found between good and poor responders. Within the good responder group, a significant decline in pHVA over time was found. By contrast, pHVA showed a transient increase in the poor responder group. Plasma MHPG changes showed a similar pattern during treatment in good responders, although no significant differences in baseline values were found between the good (n = 13) and poor (n = 9) responders, and pMHPG showed no change during treatment in poor responders. Significant correlations between baseline pHVA and pMHPG values were found in 22 patients. Good responders and poor responders did not differ significantly in terms of age, duration of illness, severity of presenting symptoms, haloperidol dose, or plasma drug concentration. Two hypothetical subtypes of schizophrenia and both dopamine and norepinephrine systems involved in schizophrenic psychopathology are proposed.

Relationships between clinical effects and monoamine metabolites and amino acids in sulpiride-treated schizophrenic patients

Twenty-four acutely ill schizophrenic patients (DSM-III-R), 18-42 years old, were treated for 6 weeks with sulpiride. Sulpiride was administered in three different daily dosages (400, 800 or 1200 mg) according to a double dummy blind randomized administration schedule. The psychopathology of the patients was rated by the Comprehensive Psychopathological Rating Scale (CPRS) and the Nurse's Observation Scale for Inpatient Evaluation (NOSIE). The monoamine metabolites homovanillic acid (HVA), 5-hydroxy-indoleacetic acid (5-HIAA), 4-hydroxy-3-methoxy-phenylglycol (HMPG) and the amino acids tyrosine, tryptophan, glutamate and glutamine were measured in serum before and once a week during sulpiride treatment. There were no significant correlations between the CPRS or the NOSIE morbidity scores and the biochemical measures before drug treatment. HVA levels were not correlated to rating scores during treatment, but after 6 weeks HVA had decreased significantly in the patients with a good response but not in the patients with a poor response. A negative relationship between 5-HIAA levels and depressive and negative symptoms was found. Non-responders according to the subscale for depression had low 5-HIAA levels throughout the treatment. An increase of tryptophan was correlated to improvement in the early part of treatment. High levels of glutamate or glutamine were found in non-responders before treatment. During treatment an increase of the glutamate level was correlated to improvement. Low levels of glutamine were related to improvement according to global and NOSIE (total) rating scores. Peripheral biochemical measures may be a valuable tool in the study of pathophysiological mechanisms and treatment effects in patients with schizophrenia.

Double blind comparative study of remoxipride and haloperidol in acute schizophrenic patients

In the present 6-week double-blind, randomised, multicentre study, the atypical neuroleptic remoxipride was compared to haloperidol in acute schizophrenic patients (DSM-III). Seventy-one patients entered the study, 36 in the remoxipride group and 35 in the haloperidol group. There were ten early withdrawals, four in the remoxipride group and six patients in the haloperidol group. The Present State Examination (PSE) profile revealed a similar reduction in the symptom clusters of psychosis in both treatment groups. Forty-seven per cent of the patients in the remoxipride group and 34% of the patients in the haloperidol group showed clinically relevant improvement (reduction of BPRS total score greater than or equal to 50%). All extrapyramidal symptoms except "glabella tap" occurred significantly less frequently in the remoxipride group as compared to the haloperidol group. Substantially lower incidences of EPS were found by active questioning in the remoxipride group compared to the haloperidol group. In addition, considerably lower incidences were observed in the remoxipride group with respect to drowsiness/somnolence, tiredness/fatigue and concentrating difficulty. At the end of treatment 66% of the patients in the haloperidol group and 22% in the remoxipride group were using anticholinergics. No consistent changes were found in the mean plasma HVA level in either treatment group. In responders (reduction of BPRS total score greater than or equal to 50%) lower baseline HVA levels were observed in both treatment groups. This study indicates that the newly developed neuroleptic remoxipride is an effective antipsychotic compound, which is clinically safe and well tolerated. In particular, few EPS were induced by remoxipride, as compared to haloperidol.

Pharmacodynamics and pharmacokinetics of haloperidol and reduced haloperidol in schizophrenic patients

Twelve male chronic schizophrenic inpatients, neuroleptic-free for at least 4 weeks, were given an oral test dose of 10 mg haloperidol (HAL) and reduced HAL (RHAL) in a random order, with a 2-week interval. Two weeks after the last test dose, the patients were given HAL, 5 mg orally twice daily for 7 days. Blood samples were drawn at baseline and between 0.5 and 24 hr after the test doses, and during HAL treatment as well. Plasma drug concentrations and homovanillic acid (HVA) levels were measured with high-performance liquid chromatography using electrochemical detection. HAL, but not RHAL, produced increments in plasma HVA (pHVA) levels at 24 hr after a test dose. pHVA levels remained higher than baseline during HAL treatment. Detectable interconversion between HAL and RHAL was observed in eight patients. The capacity of the reductive drug-metabolizing enzyme system, however, was greater than that of the oxidative processes. The plasma RHAL:HAL ratios on days 6 and 7 were higher than and positively correlated with those at Tmax after a single dose of HAL and were negatively correlated with the HAL:RHAL ratios at Tmax after a single dose of RHAL. Thus, both reductive and oxidative drug-metabolizing systems probably contribute to individual differences in plasma RHAL:HAL ratios in HAL-treated schizophrenic patients.

Plasma and CSF HVA before and after pharmacological treatment

Plasma and cerebrospinal fluid (CSF) levels of the major dopamine metabolite homovanillic acid (HVA) were measured in psychiatric patients after an average washout period of 19 days, and again after 4 weeks of pharmacological treatment. Absolute values of plasma HVA did not correlate with absolute values of CSF HVA either at baseline or after treatment. However, changes in plasma HVA were highly correlated with changes in CSF HVA. Further, while baseline levels of plasma and CSF HVA were not significantly correlated with baseline clinical measures, clinical improvement was associated with decreases in both plasma and CSF HVA. This reached statistical significance for the plasma HVA level/clinical response relationship.

Chronic haloperidol treatment with low doses may enhance the increase of homovanillic acid in rat brain

Homovanillic acid (HVA) levels were determined by high performance liquid chromatography with electrochemical detection in the striatum and prefrontal cortex of rats that had received single or repeated injections of various doses of haloperidol. Haloperidol increased the HVA concentrations in both brain regions after both acute and chronic treatment with doses of 0.01-1 mg/kg. The increase in the HVA concentrations in the striatum was blunted after repeated haloperidol injections with doses of 0.5-1 mg/kg, suggesting that haloperidol pretreatment results in a decreased responsiveness to the drug at high doses (tolerance). Tolerance also developed to the effect of long-term haloperidol treatment on the HVA concentrations in the prefrontal cortex at the highest dose used (1 mg/kg). This suggests that the differences in the development of tolerance between the striatum and prefrontal cortex are not qualitative but quantitative. However, repeated haloperidol injections at doses of 0.01-0.05 mg/kg enhanced the increase in HVA concentrations. This suggests that tolerance does not develop after chronic haloperidol treatment with low doses. Decreased HVA concentrations were also found after withdrawal from chronic haloperidol treatment (rebound decrease). However, this rebound decrease was much smaller than the decrease in response of the HVA concentrations to repeated haloperidol injections, suggesting that different mechanisms are involved.

Monoamine metabolites and amino acids in serum from schizophrenic patients before and during sulpiride treatment

Twenty-four acutely ill schizophrenic patients (DSM-III-R), 18-42 years old, were treated for 6 weeks with sulpiride. Sulpiride was administered in three different daily dosages (starting with 400, 800 or 1200 mg) according to a double blind randomized administration schedule. The monoamine metabolites (MAM) homovanillic acid (HVA), 5-hydroxy-indoleacetic acid (5-HIAA), 4-hydroxy-3-methoxy-phenylglycol (HMPG) and the amino acids tyrosine, tryptophan, glutamate and glutamine were measured in serum before treatment and once a week during treatment. There were no significant differences between healthy controls and schizophrenic patients in serum levels of monoamine metabolites and amino acids before treatment. There was no dose-response effect of sulpiride on serum levels of the monoamine metabolites or the amino acids. The results are therefore based on the whole group of patients. During treatment the HMPG levels were reduced at all points in time. The serum level of HVA was significantly reduced after 6 weeks. The 5-HIAA and the amino acid levels were not changed during treatment. There were no significant correlations among the monoamine metabolites before treatment. During treatment, however, significant correlations were found among MAM and amino acids. Since the biochemical findings during the treatment were not related to the dose or the concentration of sulpiride the results may be related to secondary biochemical effects of sulpiride and/or to changes in the clinical state following treatment.