Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Somatostatin displays a regulatory function on several aminergic neurotransmitters, including dopamine. In addition, decreased CSF levels of the peptide has been found in Schizophrenia and other neuropsychiatric disorders. 2. In the present work, we have investigated levels of plasmatic somatostatin in a sample of 50 schizophrenic patients compared with a normal control group. 3. Somatostatin was increased in the patient group (p less than 0.01) as a whole but statistical analysis revealed that the increase was associated with the presence of positive symptoms (Factorial Analysis) with a significant correlation, specially with delusion and hallucination scores in the Andreasen rating scales.
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PMID:Plasmatic somatostatin as a marker of positive symptoms of schizophrenia. 134 58

Amino acid metabolism in endogenous psychoses has been discussed in relation to monoamine synthesis. There are no consistent findings which prove altered monoamine syntheses to be the primary change. Our finding, which suggests decreased amino acid transport across the blood-brain barrier in schizophrenia, does not necessarily mean an insufficient amino acid supply to the brain. Several lines of investigation have shown the possibility of the involvement of glutamatergic dysfunction in the pathogenesis of schizophrenia. Our recent finding of decreased CSF asparagine concentration in schizophrenia and its positive correlation with the response to neuroleptics may support this hypothesis. Recently, free D-serine, an allosteric agonist on NMDA-receptor, has been reported to exist in the rat brain, suggesting that D-serine is an intrinsic ligand. The pathogeneses of endogenous psychoses might be studied in terms of disturbed metabolism of amino acid, as allosteric regulater of neuro-receptor, as well as neurotransmitter and precursor of monoamines.
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PMID:[Amino acid metabolism in endogenous psychoses: significance of amino acids as neurotransmitter, precursor of monoamines and allosteric regulator of neuro-receptors]. 135 4

The present study was designed to examine the relationship between electrodermal activity and the levels of the dopamine metabolite homovanillic acid (HVA) and the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid. Lumbar cerebrospinal fluid from 36 unmedicated and six medicated schizophrenic patients and 23 controls was analyzed by gas chromatograph-mass spectrometer. The schizophrenic patients and a group of 14 normal controls were presented with a series of orienting tones (1000 Hz, 80 db, 2-second duration) while electrodermal activity was monitored. For the patients, this occurred during an acute episode of schizophrenia. The results suggest an inverse relation between electrodermal activity and the CSF-level of HVA. Although the picture is not entirely consistent, electrodermal nonresponders appear to have normal HVA levels, while electrodermal responders have decreased levels compared with normal controls. There is also a relation between electrodermal activity and 5-HIAA, but this association is not as clear-cut as the one between electrodermal activity and HVA.
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PMID:Electrodermal orienting response and central nervous system dopamine and serotonin activity in schizophrenia. 137 92

We investigated the perceived role of stressful events in episodes of major affective disorder in patients studied in the NIMH Clinical Research Branch Collaborative Program on the Psychobiology of Depression (Biological Studies). Using items from the Schedule for Affective Disorders and Schizophrenia (SADS), episodes were divided into environment-sensitive (high perceived role of stressful events) and autonomous (minimal or no perceived role of stressful events). Patients with environment-sensitive episodes had fewer previous episodes and a longer index episode. The groups did not differ with respect to age, gender, education, socioeconomic group, diagnosis, severity of illness, or eventual response to treatment. Unipolar depressed patients with environment-sensitive episodes had lower CSF 5-HIAA than those with autonomous episodes. Among bipolar depressed patients, those with autonomous episodes had elevated excretion of O-methylated catecholamine metabolites and of epinephrine, while those with environment-sensitive episodes had normal excretion of catecholamines and metabolites. Manic subjects with environment-sensitive episodes had elevated norepinephrine excretion, while this was normal in manics with autonomous episodes. Relationships between environmental sensitivity of affective episodes and neurotransmitter function therefore appear to be related to the type of episode.
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PMID:Stress, depression, and mania: relationship between perceived role of stressful events and clinical and biochemical characteristics. 169 33

The relationship between central (cerebrospinal fluid [CSF]) and peripheral (plasma) monoaminergic metabolites and psychotic symptoms was examined in 22 drug-free schizophrenic inpatients. The CSF homovanillic acid levels did not differ significantly between patients and normal controls (n = 33). The CSF homovanillic acid levels, however, were negatively correlated with ratings of psychosis and positive symptoms, and the CSF homovanillic acid and 5-hydroxyindoleacetic acid levels correlated negatively with individual deficit symptoms. Stepwise and hierarchical multiple-regression analysis revealed that among monoaminergic measures, only the CSF and plasma homovanillic acid levels contributed significantly to the total Brief Psychiatric Rating Scale and positive symptom variance with negative and positive partial correlations, respectively. Levels of CSF 3-methoxy-4-hydroxyphenylglycol, but not of CSF norepinephrine, were significantly elevated in the schizophrenic patients compared with controls, and plasma 3-methoxy-4-hydroxyphenylglycol levels were positively correlated with negative symptoms. We discuss the potential implications of these findings for a model of dopaminergic dysfunction in schizophrenia involving distinct cortical and subcortical contributions.
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PMID:Cerebrospinal fluid and plasma monoamine metabolites and their relation to psychosis. Implications for regional brain dysfunction in schizophrenia. 169 25

It is difficult to come away from review of pharmacologic and metabolite studies without concluding that dopaminergic mechanisms play a significant role in mediating both negative and positive symptoms. Nevertheless, the characteristics of dopaminergic involvement are unclear. Whereas compelling evidence continues to link the mechanism of action of neuroleptic drugs, including therapeutic effects on negative and positive symptoms, to blockade of D2 receptors, neuroleptic-induced alterations in dopaminergic function are time-dependent and may include reductions in variability as well as in net dopamine activity. Moreover, pharmacologic enhancement of dopaminergic function may at least transiently improve symptomatology (negative greater than positive) and levels of CSF HVA appear to be reduced or are negatively correlated with symptoms in some schizophrenic patients. Thus, there is support for both increased and decreased dopamine function in schizophrenia. Functional brain imaging has, after only a few years of application, made significant contributions to our understanding of the pathophysiology of schizophrenia. Studies of cerebral metabolism and regional CBF have shown remarkable consistency in their identification of abnormal function of the frontal cortex in schizophrenia. It should be pointed out, however, that agreement across studies remains largely conceptual with significant discrepancies still existing with regard to the precise localization of dysfunction and its relationship to cognitive activation. Although less well documented than 'hypofrontality' itself, negative symptomatology appears to bear some relationship to this defect. The idea that positive symptoms might be associated with increased subcortical and/or metabolism is less well supported. The recent advances in our understanding of structure and function of CNS dopaminergic systems may help to integrate these two bodies of data into more dynamic models of dopaminergic defects in schizophrenia. For example, the concept that diminished mesocortical coupled with increased subcortical dopaminergic activity might be a 'substrate' for psychosis is compatible with neurochemical evidence suggesting both diminished and enhanced dopaminergic processes as well as with metabolic hypofrontality. Better understanding of the regulatory mechanisms involved in establishing functional balance between cortical and subcortical systems might, therefore, identify new possibilities for biological dysfunction in schizophrenia. The recent study by Weinberger et al. which correlates CSF HVA levels with neuropsychologically induced frontal CBF is an example of how neurochemistry can enhance brain imaging data.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Neurochemical and neural mechanisms of positive and negative symptoms in schizophrenia. 197 Aug 51

1. It has been proposed that an increase in the concentration of the neuromodulator phenylethylamine at the post-synaptic dopamine receptor may be involved in the etiology of schizophrenia. If this increase is the case, a reduction in the CSF and/or serum concentrations of phenylacetic acid, its major metabolite, might be anticipated. 2. The authors have found in hospitalized Indian schizophrenic patients ingesting antipsychotic drugs, that the paranoid subgroup did indeed exhibit lower levels of unconjugated, conjugated and total phenylacetic acid in both serum and CSF.
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PMID:Phenylacetic acid in CSF and serum in Indian schizophrenic patients. 200 39

Neuropeptide Y-like immunoreactivity (NPY-li) was measured in CSF of 35 drug-free chronic schizophrenic patients. Compared to a group of drug-free controls, CSF NPY-li was significantly higher in these patients. CSF NPY-li decreased with age and longer duration of illness. Measures of structural brain abnormalities on CT scans were significantly associated with lower CSF NPY-li. Relationships between NPY-li and schizophrenic behavior, i.e. positive symptoms, were observed only in the clinically stable (nonrelapsed) drug-free patients. In 31 of the patients CSF was obtained before and after withdrawal from haloperidol maintenance treatment. This withdrawal from haloperidol treatment was associated with a significant increase in CSF NPY-li. There was no significant difference in CSF NPY-li between patients who did and those who did not relapse within 6 weeks following haloperidol withdrawal. The present findings suggest a relationship of CSF NPY-li with various aspects of schizophrenia.
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PMID:Neuropeptide Y-like immunoreactivity in schizophrenia. Relationships with clinical measures. 217 1

The experiment adopted radioimmunoassay to assay CSF, platelets cAMP cGMP levels of a group of Schizophrenia patients, and made a correlation analysis between the cAMP, cGMP and the evaluated factor scores of BPRS and SCL-90. The results showed: (1)CSF cAMP level of Schizophrenics was significantly higher than normal controls; (2)There was a significantly positive correlation between CSF cAMP and BPRS factor 1, a significantly negative correlation between platelets cAMP and BPRS factor 3, a significantly positive correlation between CSF cAMP and SCL-90 factor 5,8. The paper discussed the similarities and differences between the results of this experiment and the former studies.
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PMID:[Assaying the SCF platelets cyclic nucleotides of schizophrenics and analyzing its correlation with pathopschological factors]. 217 85

Several lines of evidence indicate altered noradrenergic function in schizophrenia. The authors examined resting, standing, and change (standing minus resting) in plasma norepinephrine levels in 14 drug-free patients with chronic schizophrenia or schizoaffective disorder and in 33 age- and sex-matched healthy volunteers. Schizophrenic patients had significantly higher resting and standing plasma norepinephrine levels and significantly greater change. Resting and standing levels were significantly related to positive and negative symptoms. There was a significant positive correlation between resting plasma and CSF norepinephrine levels and a significant negative correlation between CSF homovanillic acid and resting, standing, and change in plasma norepinephrine levels.
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PMID:Plasma norepinephrine in chronic schizophrenia. 222 Nov 57


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