Biomedical subjects

J Licinio

Publications and source records attributed to J Licinio.

7 recordsLinked to original sources

PubMed1992

Induction of constitutive heat shock protein 73 mRNA in the dentate gyrus by seizures.

We examined the effects of generalized seizures on heat shock protein (hsp) mRNA induction in the rat brain using in situ hybridization. Seizures induced by electroconvulsive shock, electrical or cocaine kindling caused a selective induction of the constitutive hsp 73 gene in the dentate gyrus. In these seizure paradigms, not thought to induce widespread tissue damage, neither the heat-inducible hsp 72 gene nor a member of the hsp 90 family (hsp 84) were induced. Hsp 73 may play a role in the adaptation and/or in the maintenance of dentate granule cell integrity following seizures.

Amygdala↗

PubMed1992

Neutrophil-activating peptide-1/interleukin-8 mRNA is localized in rat hypothalamus and hippocampus.

Neutrophil-activating peptide-1/interleukin-8 (NAP-1/IL-8) is a cytokine synthesized by various cell types. In the immune system NAP-1/IL-8 is part of an immune cascade initiated by IL-1 production. NAP-1/IL-8 affects hypothalamic function and its production is suppressed by steroids. Therefore, it might be expected that NAP-1/IL-8 would be produced in brain areas involved in the control of the hypothalamic-pituitary-adrenocortical axis (HPA). NAP-1/IL-8 mRNA was localized by in situ hybridization in the paraventricular nucleus of the hypothalamus and hippocampus. Those areas also express the genes encoding interleukin-1-alpha (IL-1 alpha), IL-1 beta, IL-1 receptors, and IL-1 receptor antagonist (IL-1ra). This suggests that an immune cascade, which is well characterized in the immune system, may exist in brain, in areas of relevance to the regulation of stress-related neuroendocrine function.

Animals↗

PubMed1992

Acute tryptophan depletion: a method of studying antidepressant action.

Serotonin (5-HT) has been implicated in the pathophysiology of depressive syndromes and in the mechanism of antidepressant drug action. Rapid dietary depletion of tryptophan (TRP) provides a paradigm for studying the role of 5-HT in depressed patients. Drug-free depressed patients do not show mood changes during TRP depletion but about one third have a clinically apparent, transient improvement in mood on return to normal TRP intake. Depressed patients in clinical remission after 6 to 8 weeks of antidepressant therapy experience a transient depressive relapse during acute TRP depletion. The significance of these findings will be discussed. Tryptophan depletion in other psychiatric syndromes will also be reviewed.

Antidepressive Agents↗

PubMed1991

Role of corticotrophin releasing hormone 41 in depressive illness.

CRH seems to be of fundamental importance in depressive illness. Melancholic depressed patients, with a syndrome of hyperarousal, have increased activity of CRH-producing neurones. Conversely, there is evidence to support the notion that patients with atypical depression, a syndrome of hypoarousal, have decreased activity of CRH-producing neurones. CRH-induced kindling is a possible model for the natural history of depressive illness. Finally, effective treatments for depressive illness, such as tricyclic antidepressants, decrease CRH production, and drugs, such as carbamazepine, effective in preventing the recurrence of affective disorder, also decrease CRH production. Interestingly, these drugs are not particularly effective in the treatment of atypical depression, which seems to be related not to an activation of CRH-producing neurones, but rather to a decrease of CRH secretion.

Animals↗

PubMed1991

Decrease in resting metabolic rate during abstinence from bulimic behavior.

Among eight normal-weight bulimic women studied during 1 week of binge eating and vomiting and 7 weeks of abstinence without weight loss, resting metabolic rate and T3 and T4 levels fell significantly during abstinence. These data suggest that a physiological consequence of binge eating and vomiting is an increase in metabolic rate, in part due to increased thyroid hormone activity.

Adult↗

PubMed1991

Localization of interleukin-1 receptor antagonist mRNA in rat brain.

Interleukin-1 (IL-1) is an inflammatory peptide hormone, with potent neuroendocrine effects. IL-1 stimulates the central nervous system production of corticotropin-releasing hormone (CRH), growth hormone (GH), thyroid-stimulating hormone (TSH), and somatostatin, and inhibits the secretion of prolactin and luteinizing hormone (LH). Interleukin-1 receptor antagonist (IL-1ra) is a novel cytokine, recently purified, characterized, and cloned. IL-1ra is a pure endogenous antagonist of IL-1:IL-1 function is modulated not only by local levels of IL-1, but also by the levels of IL-1ra. We have localized by in situ hybridization histochemistry IL-1ra mRNA in rat brain, in areas of importance to neuroendocrine function, such as the paraventricular nucleus (PVN) of the hypothalamus, hippocampus, as well as cerebellum. These findings indicate that IL-1ra is produced in brain in areas of relevance to the regulation of neuroendocrine function and suggest that IL-1ra may modulate the neuroendocrine effects of IL-1.

Animals↗

PubMed1991

Rapid serotonin depletion as a provocative challenge test for patients with major depression: relevance to antidepressant action and the neurobiology of depression.

Brain serotonin (5-HT) content is dependent on plasma levels of the essential amino acid, tryptophan (TRP). We have previously reported on the effects of rapid dietary TRP depletion in psychiatric patients; this study extends those reports and summarizes the effects of rapid TRP depletion on mood in depressed patients. One hundred and fifteen depressed (according to DSM-III-R) patients (69 drug free and symptomatic; 46 in clinical remission after antidepressant treatment) received tryptophan depletion testing in a double-blind, placebo-controlled, crossover fashion. Of 69 symptomatic, drug-free, depressed patients, 30 percent were unchanged the day of the tryptophan-free drink (TFD), but became clinically less depressed the day after the TFD. Although 80 percent of monoamine oxidase inhibitor- or fluvoxamine-treated patients experienced a depressive relapse during TRP depletion testing, only 18 percent of desipramine-treated patients relapsed. Brain 5-HT function may be intimately involved in the modulation of some affective states and in the mechanism of action of some antidepressant medications.

Antidepressive Agents↗