Cerebrospinal fluid levels of somatostatin, corticotropin-releasing hormone and corticotropin in alcoholism

CSF CRH in abstinent cocaine-dependent patients

Alterations in stress responsivity may be important in the vulnerability to become cocaine dependent. Thus, an index of hypothalamic-pituitary-adrenal (HPA) axis function was examined in abstinent cocaine-dependent patients. Cerebrospinal fluid (CSF) concentrations of corticotropin releasing factor (CRH) were determined in 29 abstinent cocaine-dependent patients and 66 normal controls. The results showed that there was no significant difference between the abstinent cocaine-dependent patients and normal controls for CSF CRH. Also, CSF CRH concentrations were not related to cocaine-craving scores in a cue-elicited cocaine-craving procedure. Thus, these data suggest that after protracted abstinence from cocaine there is no marked dysregulation of CRH systems as measured by CSF CRH concentrations.

Cerebrospinal fluid neuroendocrinology of alcohol misusers

Cerebrospinal fluid (CSF) neurohumors reflect central nervous system physiology in a way that peripheral indices can not. We reviewed clinical studies of CSF biogenic amines and neurohormones in alcohol misusers during various stages of withdrawal or abstinence and found them difficult to compare because of highly variable experimental methods, reliance on single time collections (lumbar punctures) that fail to control for potential stress-induced effects of the procedure, lack of control for tobacco use, and a paucity of non-alcoholmisusing controls. However, taken together, the data thus far show that a variety of neuroactive substances are reduced in concentration in the CSF of some alcohol misusers. Low CSF levels of corticotropinreleasing hormone, beta-endorphin, norepinephrine, diazepam-binding inhibitor, 5-hydroxyindoleacetic acid and somatostatin have all been reported. Whether the decreased CSF levels of these neurohormones and neurotransmitters are a cause or consequence of alcoholism has not been determined. In fact, further studies using serial or continuous CSF sampling techniques with homogeneous, better-characterized patients and normal volunteers are still needed to establish the precise CSF neurochemical abnormalities in alcohol misusers.

Proteinergic profiles in cerebrospinal fluid from alcoholic subjects

Minute amounts of cerebrospinal fluid samples from alcoholics were subjected to separation by HPLC-molecular sieving, combined with multispectral UV analysis of the acquired data. A significant difference in the protein/polypeptide pattern within the molecular weight range of 7-10 kDa has been observed between samples, taken directly after detoxification and 2 weeks later. Spectral analysis of the results suggests that the components are of peptidergic nature. On the other hand, albumin content did not differ significantly, suggesting that the blood-brain barrier was not affected. An enzyme marker, dynorphin converting enzyme, remained unchanged in both groups.

Cerebrospinal fluid neuropeptides in mood disorder and dementia

Cerebrospinal fluid (CSF) concentrations of immunoreactive corticotropin-releasing hormone (CRH) and somatostatin (SRIF) were measured in female psychiatric inpatients with DSM-III-R diagnoses of major depression, mania, generalized anxiety and somatization disorder. In addition, elderly patients with dementia disorders, with or without concomitant major depression, were also investigated. CSF SRIF was not significantly different among these groups; on the other hand, mean CSF CRH concentrations were significantly higher in major depression and in dementia with depression as compared with neurological controls with no psychiatric disorders. CSF CRH levels in mania, simple dementia, or anxiety or somatization disorder were not significantly different from the controls. Background physical or clinical variables did not account for the differences in CRH concentrations. It is concluded that CSF CRH elevation may be present in some patients with major depression independent of age and an underlying dementia disorder.

Cerebrospinal fluid variables among alcoholics lack seasonal variation

Seasonal influences on indices of serotonergic function, including cerebrospinal fluid (CSF) concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA), have been reported in psychiatric patients and healthy volunteers. We examined seasonal differences in CSF concentrations of 5-HIAA among 135 alcoholics admitted to a research ward who had a lumbar puncture. No significant seasonal differences were found for either CSF concentrations of 5-HIAA or CSF concentrations of other monoamine metabolites or peptides. The possible explanations for these negative findings are discussed.

Neuroendocrine responses to serotonergic agents in alcoholics

Previous studies have suggested a possible deficit in serotonergic function in alcoholism. In order to further assess the serotonergic system in alcoholism, the plasma cortisol and prolactin (PRL) responses following 6-chloro-2-[1-piperazinyl]pyrazine (MK-212), a direct-acting serotonin2 (5-HT2)/5-HT1c receptor agonist, L-5-hydroxytryptophan (L-5-HTP), a precursor of 5-HT, and placebo were compared in male alcoholics and normal controls. The increase in plasma cortisol following L-5-HTP was significantly lower in the alcoholic subjects compared with the normal controls. The plasma PRL, but not the plasma cortisol response, following MK-212 was also significantly lower in the alcoholics. L-5-HTP had no significant effect on plasma PRL levels in either group. The basal plasma cortisol and PRL concentrations of the alcoholics and normal controls were not significantly different. These data are consistent with previous reports of a serotonergic abnormality in alcoholism.

CSF neuropeptide Y in alcoholics and normal controls

Neuropeptide Y is found in brain tissue. In dogs it has been shown to enhance activation of the hypothalamic-pituitary-adrenal axis by corticotropin-releasing hormone. It is localized in certain catecholamine neurons and to some extent colocalized with somatostatin. Disturbances of the central noradrenergic system may underlie some forms of alcoholism. Therefore, we compared male alcoholics and normal controls on cerebrospinal fluid (CSF) levels of neuropeptide Y. There was no significant difference between the two groups for neuropeptide Y. There was also no significant difference for CSF levels of growth hormone releasing hormone. However, there were significant positive correlations between CSF levels of neuropeptide Y and CSF levels of corticotropin-releasing hormone, somatostatin, and growth hormone releasing hormone.