CSF somatostatin and abnormal response to dexamethasone administration in schizophrenic and depressed patients

Low levels of cerebrospinal fluid (CSF) somatostatin and abnormal response to dexamethasone are two neuroendocrine disturbances reported to appear in depression and other neuropsychiatric disorders. We measured the levels of CSF somatostatin in patients with schizophrenia (n = 44) and depression (n = 19). In view of in vitro and animal evidence of the ability of somatostatin to inhibit stimulated corticotropin secretion, we also administered the dexamethasone suppression test to a subgroup of the patients with schizophrenia (n = 16) and the total depressed group. Lower levels of CSF somatostatin were found in dexamethasone nonsuppressors regardless of diagnosis and were negatively correlated with maximum postdexamethasone cortisol level in the total and depressed patient groups. These data suggest a functional relationship between hypothalamic-pituitary-adrenal axis hyperactivity and reduced CSF somatostatin level.     

Cerebrospinal fluid somatostatin and psychiatric illness

Somatostatin is a tetradecapeptide that is assuming increasing importance as a regulator of central nervous system activity. Originally identified as the hypothalamic growth hormone release-inhibiting factor, somatostatin has subsequently been shown to be extensively and selectively distributed throughout the central nervous system, to alter neuron excitability, to regulate and be regulated by the activity of classical neurotransmitters and neuropeptides, to exert a number of direct behavioral actions, and to display neuropsychiatric disorder-related alterations. In this article, a three-part study of cerebral spinal fluid (CSF) somatostatin in affective illness and schizophrenia is presented. In part 1, significant reductions in CSF somatostatin were observed in 49 bipolar and unipolar depressed patients relative to 47 controls. Values during depression were also significantly lower than those observed in affective disorder during the improved state or in schizophrenia. Diurnal studies involving paired AM and PM lumbar punctures revealed that depressed patients and normal volunteers had similar somatostatin values in the evening, despite having significantly different values in the morning. In part 2, the effects of several psychopharmacological agents on CSF somatostatin were examined, particularly the tricyclic anticonvulsant carbamazepine. A significant reduction of CSF somatostatin during treatment with carbamazepine was observed. The effect of carbamazepine on somatostatin could be related to its anticonvulsant, analgesic, or psychotropic effects. Part 3 deals with somatostatin as a major regulator of hypothalamic-pituitary-adrenal (HPA) axis activity. Somatostatin affects HPA activity by inhibiting, at a number of cellular levels, the stimulated release of adrenocorticotrophic hormone (ACTH) from the pituitary. A significant negative relationship between CSF somatostatin and the postdexamethasone plasma cortisol level in 22 depressed and 16 schizophrenic patients was observed. This relationship between low CSF somatostatin and escape from dexamethasone suppression was observed irrespective of diagnosis (i.e., depression or schizophrenia). Thus, there is indirect supporting evidence for a role for somatostatin dysregulation in the most consistently observed biological abnormality in depression, escape from dexamethasone suppression. Further study of somatostatin in neuropsychiatric disorders, and particularly depressive illness, offers great promise for better understanding their underlying affective, vegetative, cognitive, and physiological dysregulations.     

Platelet monoamine oxidase and sex hormones in a population of depressed patients

The association between changes in platelet MAO activity and Major Depressive Episode have been demonstrated. Cyclical changes in sex hormones serum levels had never been related with changes of MAO activity in depressed patients. Platelet MAO activity, oestrogen serum levels, progesterone serum levels and testosterone serum levels, have been measured in drug free depressed patients: 22 men and 42 women. This study demonstrates no relationship between serum levels hormons and platelet MAO activity, measured in men and in women. If young women are separated from menopaused women, platelet MAO activity is negatively correlated with oestrogen serum levels, in non menopaused women. Significance of this variation in studies about the use of MAO as a biochemical marker in depression is discussed.     

抑郁症患者脑脊液生长抑素及单胺代谢产物的测定

目的 探讨抑郁症可能的生化病理机制,方法 采用放射免疫测定法及高效液相色谱法,分别测定２７例抑郁症患者和２７例对照者脑脊液（ＣＳＦ）生长抑素（ＳＳ）及单胺代谢产物水平。结果抑郁症组ＧＳＦ中ＳＳ水平和３－甲氧－４羟苯乙二醇（ＭＨＰＧ）水平（Ｐ〈０．０５）和５－羟吲哚乙酸水平（Ｐ〈０．０１）,均低于对照组,而抑制症组ＣＳＦ中高香草酸含量与对照组间的差异无显著性（Ｐ〉０．０５）;抑郁症组ＣＳＦ中ＳＳ与Ｍ     

CSF somatostatin in affective illness and normal volunteers

Somatostatin is a hypothalamic tetradecapeptide with many central nervous system actions. We investigated a potential role for altered somatostatin activity in affective disorder by measuring somatostatin in the cerebrospinal fluid (CSF) of 47 patients with affective disorder and of 39 normal volunteers. Medication-free depressed patients showed significantly lower levels of CSF somatostatin than normal volunteers (p less than .001) or patients during the improved state (p less than .01). Somatostatin levels were significantly and inversely correlated with duration of sleep on the night of the lumbar puncture (p less than .05). Treatment with carbamazepine reduced CSF somatostatin (p less than .01) in contrast to the absence of effect of imipramine, desmethylimipramine, and lithium carbonate and the significant increase in CSF somatostatin seen in a small group of patients treated with zimelidine. The implications of these findings with respect to attempts to explore the neurobiology of depression are discussed.     

Concentrations of monoamine metabolites in the cerebrospinal fluid of twins and unrelated individuals--a genetic study

The concentrations of the major monoamine metabolites, homovanillic acid (HVA), 3-methoxy-4-hydroxyphenylethylene glycol (MOPEG), and 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid (CSF), of platelet monoamine oxidase (MAO) and of dopamine beta-hydroxylase (DBH)-activity in serum and CSF were determined in pairs of healthy mono- and dizygotic twins, brothers and unrelated individuals. Intraclass correlations were calculated for each category of pairs. Of the monoamine metabolites, only MOPEG was found to be under any major genetic influence. Genetic heritability for MOPEG was 0.74 with no evidence of cultural heritability or environment common to twins. For HVA and 5-HIAA, a familial influence was found, where the cultural heritability was higher than the genetic. As in previous studies of MAO in blood platelets and of DBH activity in serum, there was strong evidence for a genetic component. The genetic heritability for MAO was 0.78. For DBH in serum the genetic component was 0.98, and for DBH in CSF, 0.83. The demonstration of a familial influence on 5-HIAA and HVA in CSF requires a more detailed analysis of the character of such environmental and genetic influences, using more direct techniques.     

CSF somatostatin in patients with Alzheimer's disease, older depressed patients, and age-matched control subjects

Somatostatin-like immunoreactivity was measured in the CSF of 12 patients with Alzheimer's disease, 15 age-matched control subjects, and 20 older depressed subjects. Patients with dementia or depression were found to have lower CSF somatostatin concentrations than control subjects despite markedly different clinical presentations. Severity of depression was clearly different in all three groups but showed no significant correlation with CSF concentration of somatostatin. There was a significant positive correlation between CSF somatostatin-like immunoreactivity and cognitive functioning in all 47 subjects, but this association was not statistically significant within individual diagnostic groups. These data raise interesting questions about possible biological links between Alzheimer's disease and depression in older patients.     

Platelet MAO activity and the cortisol response to dexamethasone in major depression

Previous studies have sometimes found a positive relationship between platelet monoamine oxidase (MAO) activity and dexamethasone nonsuppression in depressed patients. To assess this relationship in more detail, we examined the association between these two biological variables in unmedicated depressed patients. A positive correlation between platelet MAO activity and 8:00 AM serum cortisol levels following an overnight dexamethasone test (1 mg) was observed. The relationship between high and low platelet MAO activity (median split) and suppression of serum cortisol levels was also significant. These relationships were stronger in bipolar patients. Multiple regression revealed that postdexamethasone 8:00 AM dexamethasone levels and platelet MAO activity were independent predictors of the 8:00 AM cortisol levels following dexamethasone. The possibility that platelet MAO activity may be a peripheral marker of brain serotonergic activity which in turn may affect various aspects of the hypothalamo-pituitary-adrenal axis activity, is discussed. We also found that all nine depressed patients studied greater than or equal to 15 days after admission were suppressors. Platelet MAO activity, but not 8:00 AM pre- or postdexamethasone serum cortisol, was related to the severity of depression.     

Changes in the concentration of somatostatin and substance P in the cerebrospinal fluid following injection of alcohol into the pituitary gland

The concentration of immunoreactive somatostatin and Substance P in the cisternal cerebrospinal fluid (CSF) of patients with pain due to malignant disease has been measured before and after injection of alcohol into the pituitary fossa. Following the first injection, a rise of 108 +/- 66% in CSF somatostatin levels was observed in 7 out of 13 patients, and a rise of 87 +/- 26% in 4 out of the 5 patients undergoing a second injection. A rise of 179 +/- 99% in levels of Substance P in CSF was observed in 4 out of 8 patients after a single injection. No change in peptide concentration was detected in peripheral plasma. Changes in CSF levels did not correlate with the degree of pain relief obtained, but patients with the greatest increase in somatostatin subsequently developed diabetes insipidus. The data are consistent with our previous experience that injection of alcohol into the pituitary fossa can cause destruction to nervous tissue, in addition to the obvious destruction of pituitary gland tissue. They do not support the suggestion that hypothalamic damage is necessary in order to obtain pain relief.     

Aspects of cellular immunity in multiple sclerosis. Antigen-reactivity of lymphocytes and lymphokine activity.

Some new results of cell-mediated immunity in multiple slcerosis (MS) are presented, based on the determination of charge-changing lymphokines as products of antigen sensitive lymphocytes (C PAL), obtained by several forms of the electrophoretic mobility (EM) method. Lymphocytes from MS react to myelin basic protein (BP), the reactivity in other neurological diseases depending on the degree of destruction of nervous parenchyma. Applying a membrane-associated antigen from normal brain (NTA), positive reactivity of MS lymphocytes was obtained. Besides the usual determination of lymphokines in vitro the sensitive EM test allows the demonstration of lymphokine activities in vivo; i.e. in body fluids such as cerebrospinal fluid (CSF) and serum. In CSF of MS a high lymphokine activity was found. The differentiation of lymphokines and comparison between in vitro and in vivo activity were carried out. Moreover, a characteristic lymphokine pattern for MS with high activities in all regions of molecular weight, especially in the CSF, could be detected. On the basis of these findings, important also from the pathogenetic point of view, a diagnostic scheme for MS is suggested, consisting of a program of determination of the immuno-reactive CSF syndrome and some special procedures, including examination of lymphocyte reactivity.     

The Marke-Nyman Temperament (MNT) scale in relationship with monoamine metabolism and corticosteroid measures in suicide attempters

Abstract

Various monoaminergic measures as well as corticosteroid deviances have repeatedly been linked to depression or suicidal behavior. With the purpose to study these biological markers in relationship with temperament, the Marke-Nyman Temperament (MNT) questionnaire was administered in a sample of 89 suicide attempters. The subjects were diagnosed according to the DSM-III-R and subgrouped according to suicide method into “violent” and “nonviolent” attempters, and into “repeaters” (with previous attempt) and “nonrepeaters” (without previous attempts). The subjects were also subgrouped according to MNT patterns into 5 MNT clusters. Lumbar punctures were performed and the monoamine metabolites homovanillic acid (HVA). 5-hydroxyindoleacetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycole (MHFG) in the cerebrospinal fluid (CSF) were analysed. The levels of plasma cortisol and 24. urinary cortisol were determined and dexamethasone suppnssion tests (DST) were performed. The activity of the enzyme monoamine oxidase (MAO) in platelets was determined.

Among the alcoholic patients, the biological markers showed several specific correlations with temperament. In this group. low Solidity (reflecting impulsiveness) was significantly associated with low levels of CSF HVA. CSF 5-HIAA. urinary cortisol and low platelet MAO activity. The Stability (reflecting emotional distance towards others) was significantly and positively associated with urinary cortisol and platelet MAO activity. This seems to reflect the two previously described subgroups of alcoholism, with early and late onset, respectively.

In the whole sample, we found a positive correlation between urinary cortisol and Stability. The biological markers showed no clear differences between the MNT clusters. We could not replicate earlier findings of an association between impulsiveness (low solidity) and low levels of 5-HIAA or low MAO activity in platelets in the whole sample of suicide attempters.     

CSF somatostatin in anorexia nervosa and bulimia: relationship to the hypothalamic pituitary-adrenal cortical axis

The eating disorders, anorexia nervosa and normal weight bulimia, are associated with disturbances of hypothalamic-pituitary-adrenal cortical (HPA) and growth hormone function. Because somatostatin (SRIF) is one of the neuropeptides known to modulate feeding behavior and neuroendocrine systems, we measured cerebrospinal fluid (CSF) concentrations of this peptide in patients with eating disorders. CSF SRIF concentrations in patients with anorexia nervosa, both at low weight and after weight recovery, were similar to those in controls. When normal weight bulimic women stopped binging, they had a modest but significant increase in CSF SRIF. CSF SRIF was not related to plasma growth hormone concentrations but did show relationships to HPA axis hormones. Healthy volunteer women had a significant positive relationship between CSF SRIF and CSF corticotropin releasing hormone (CRH). In underweight anorectics, CSF SRIF was negatively related to both 24-hr urinary free cortisol and plasma cortisol concentrations after dexamethasone, but it was not significantly related to CSF CRH. These relationships more closely resembled those of healthy controls after weight correction. In bulimics, CSF SRIF was positively related to CSF CRH and negatively related to plasma cortisol. Our findings support a previously described relationship between CSF SRIF and HPA axis activity. The differences in SRIF-HPA relationships in anorectics and bulimics may constitute or reflect pathophysiological distinctions between these disorders.     

Serum 25-Hydroxyvitamin D Levels and Depression in Older Adults: A Dose–Response Meta-Analysis of Prospective Cohort Studies

ObjectiveThe association between serum vitamin D and risk of depression in older adults is controversial. We performed a dose–response meta-analysis of prospective cohort studies to examine the association between serum 25-hydroxyvitamin D [25(OH)D] concentrations and the risk of depression in older population.MethodsStudies published before February 2018 in the PubMed, Cochrane Library, Web of Science, PsycINFO, and EMBASE databases were systematically searched. Prospective cohort studies that examined the association between serum 25(OH)D levels and the risk of depression in older adults were included. A random-effects model was used to calculate the pooled hazard ratio and the corresponding 95% confidence intervals. A nonlinear dose–response association was examined using restricted cubic spline functions.ResultsSix prospective studies covering 16,287 older adults with 1,157 cases of depression were included and analyzed. The pooled hazard ratio of depression for per 10-ng/mL increment in serum 25(OH)D was 0.88 (95% confidence intervals: 0.78–0.99, I² = 79.0%, p <0.001 for heterogeneity). A linear dose–response association between serum 25(OH)D concentrations and incident depression was observed (p = 0.96 for nonlinearity).ConclusionSerum 25(OH)D concentration is negatively associated with the risk of depression in older adults. This meta-analysis suggests that increasing 25(OH)D levels may be a useful approach to reduce the risk of depression in older adults and highlights the need for further large-scale clinical studies.     

Low CSF somatostatin associated with response to nimodipine in patents with affective illness.

BACKGROUND: In patients with depression, treatment with nimodipine has been shown to increase cerebrospinal fluid (CSF) somatostatin (SRIF) and ameliorate baseline global cerebral hypometabolism. This study was conducted to assess whether a low baseline level of CSF SRIF was associated with response to nimodipine treatment.METHODS: Twenty-one depressed patients underwent lumbar puncture for analysis of CSF somatostatin-like immunoreactivity (SRIF-LI) during a medication-free period and after at least 6 weeks of nimodipine monotherapy. Twenty-five healthy control subjects were utilized as a comparison group. Clinical improvement was assessed using the Clinical Global Impression Scale for Bipolar Illness.RESULTS: As predicted, baseline CSF SRIF-LI was significantly lower in eventual nimodipine responders (33.1 +/- 2.8 pg/mol) compared to eventual nonresponders [41.9 +/- 2.6 pg/mL; t(19) = 1.98, p =.03, one-tailed].CONCLUSIONS: Low baseline CSF somatostatin in depression may be associated with response to nimodipine, which in turn may be related to the ability of nimodipine to increase CSF somatostatin.     

Pre- and post-dexamethasone salivary cortisol concentrations in major depression

Seventy patients fulfilling DSM-III criteria for major depression were given the 1.0 mg overnight dexamethasone suppression test, with salivary cortisol concentrations being measured as the dependent variable. Using both the DSM-III and the Research Diagnostic Criteria, we categorized the patients into four groups based on increasing frequency of endogenous symptomatology. Among these four groups there were no significant differences in salivary cortisol concentrations either before dexamethasone or eight, 16, and 24 h after dexamethasone. Similarly, there were no significant differences among the groups in either the ratios of post- to pre-dexamethasone salivary cortisol or the frequencies of positive tests based on several criterion levels of cortisol for the three post-dexamethasone samples. Multiple regression analyses indicated that the Hamilton depression rating scale item “somatic anxiety” was significantly negatively related to post-dexamethasone cortisol concentrations. We conclude that, for our sample of major depressives, the salivary cortisol dexamethasone suppression test showed no utility as a laboratory correlate of depressive episodes with endogenous features.     

Relationship between platelet MAO activity and concentrations of 5-HIAA and HVA in cerebrospinal fluid in chronic pain patients

Summary Platelet monoamine oxidase (MAO) activity and concentrations of 5-HIAA and HVA in the cerebrospinal fluid (CSF) were estimated in a series of 54 chronic pain patients. Platelet MAO activity was found to correlate, positively to CSF concentrations of 5-HIAA and HVA, which had been adjusted in order to eliminate the influence of age and body height. However, only the correlation with 5-HIAA reached a significant level. When partial correlations were sought, only the positive correlation between platelet MAO activity and CSF 5-HIAA remained. The results support the notion that platelet MAO ia a biological marker for some trait dependent property of the central serotonergic system.Supported in part by grants from the Swedish Medical Research Council (grants No. 166, 4145 and 5740).     

Self-rated aggression related to serum testosterone and platelet MAO activity in female patients with the fibromyalgia syndrome.

To investigate self-rated aggression in relation to platelet MAO activity and serum testosterone in patients with fibromyalgia syndrome (FMS), we administered the Aggression Questionnaire - Revised Swedish Version (AQ-RSV) to 30 female patients with FMS. After correction for age, significant positive correlations were seen between serum testosterone concentrations and the AQ-RSV scores for Verbal Aggression (r=0.36, p<0.05) and Anger (r=0.37, p<0.05), whereas the platelet MAO activity was negatively correlated with the score for Verbal Aggression (r=-0.44, p<0.05). Our results suggest that aggression and irritability in female FMS patients might be increased by elevated testosterone concentrations in combination with reduced capacity of the serotonergic system as reflected by low platelet MAO activity.     

The circadian variation of catecholamine metabolism in the subhuman primate

Cerebrospinal fluid (CSF) was removed continuously in 2- or 3-h aliquots from the lateral and fourth cerebral ventricles of chronic chair restrained rhesus monkeys. Under conditions of 12 h light (06.00-18.00 h) and 12 h darkness (18.00-06.00 h) the concentrations of norepinephrine (NE) were found to describe a circadian pattern, with maximal concentrations occurring during the light hours and minimal concentrations occurring during the dark hours. The patterns were generally coincident with the circadian patterns of brain temperature and body activity. When assayed for 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) and 3-methoxy-4-hydroxymandelic acid (VMA), samples of CSF collected over 3-4 days demonstrated no reproducible pattern of change. Fluctuation in the concentration of MHPG did not correspond in direction or magnitude to changes in the concentration of VMA. These random fluctuations may in part be accounted for by the influx of the metabolites from peripheral sources to the brain and CSF, and by the relatively slow movement of these metabolites as they diffuse from brain parenchyma to the CSF.     

The effect of lamotrigine on platelet monoamine oxidase type B activity in patients with bipolar depression

Lamotrigine is an anticonvulsant drug effective in the treatment of epilepsy and bipolar depression. Preclinical data showed that lamotrigine inhibited monoamine oxidase (MAO) activity in vitro. The aim of the study was to determine the effects of 6-weeks lamotrigine treatment on platelet MAO type B (MAO-B) activity in patient with bipolar depression. The study included 26 female patients with bipolar I disorder in depressive episode (DSM-IV criteria, Hamilton Depression Rating Scale (HAMD) and Young Mania Rating Scale). Platelet MAO-B activity was determined spectrofluorimetrically before and after 6 weeks of the treatment with a relatively low dose of lamotrigine (100 mg/day). Six weeks of treatment with lamotrigine significantly decreased platelet MAO-B activity in bipolar depressed patients. This inhibitory effect was not related to smoking status and was independent of the treatment combinations (lamotrigine alone or in combination with either lithium or antipsychotics). Lamotrigine treatment induced a decrease in total HAMD scores in bipolar depressed patients, which was not significantly correlated with reduction of platelet MAO-B activity. These findings provide in vivo insight of lamotrigine effect on platelet MAO-B activity in patients with bipolar depression. Its in vivo MAO-B inhibiting effect might have contributed in part to its antidepressant activity.