Inflammatory markers in Alzheimer's disease and multi-infarct dementia.

Inflammation has been involved in the pathogenesis of dementia. The study evaluates the presence and the source of pro- and anti- inflammatory cytokines in the blood of patients with Alzheimer's disease (AD), multi-infarct dementia (MID) or in non-demented elderly people (controls). Tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, IL-10, IL-1 receptor antagonist (IL-1Ra) and soluble TNF receptor I (sTNF-RI) plasma concentrations and release from blood cells stimulated with lipopolysaccharide (LPS, 1 microg/ml) were determined. The results show that TNF-alpha released from blood cells is significantly decreased (27%) in all demented patients compared to controls. Circulating TNF-alpha is increased (400%) only in MID patients. In these patients plasma levels of sTNF-RI are increased (53%) and IL-10 from stimulated blood cells decreased (47%) compared to non-demented subjects. The results show that: (1) peripheral production of TNF-alpha is blunted in demented (both AD and MID) patients compared to non-demented age-matched subjects; (2) AD patients have a selective disregulation of the peripheral TNF-alpha system; (3) different cytokines are up- or down- regulated in MID patients showing that in this condition the pro- and anti-inflammatory peripheral cytokine system is more widely affected.

Citocinas circulantes en la enfermedad de Alzheimer / Circulating cytokines in alzheimer´s disease

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Sleep regulation: interactions among cytokines and classical neurotransmitters.

The role of classical neurotransmitters in sleep regulation is amply documented (Hobson and Steriade, 1986). In recent years evidence has been gathered that immunoactive molecules, infectious agents and their components, or cytokines play some part in sleep regulation (Krueger and Obál, 1994; Opp et al., 1992; Moldofsky, 1994). Different cytokines possess hypnogenic properties when injected centrally or systemically to different animal species and their role in physiological sleep regulation is currently under investigation. Little is known of how cytokines and classical neurotransmitters interact and of the relevance of this interaction in sleep induction and maintenance. The present paper (i) reviews data on this topic; (ii) proposes a unitary interpretation whenever possible; and (iii) raises questions that might be addressed by future studies.

Effect of buspirone and its metabolite 1-(2-pyrimidinyl)-piperazine on hippocampal serotoninergic system, studied in freely moving rats.

The effects of the anxiolytic drug buspirone and its metabolite 1-(2-pyrimidinyl)-piperazine (1PP) were studied on the serotoninergic system in the hippocampus of freely moving rats. Pulse voltammetry was used in association with chronically implanted carbon fiber microelectrodes to record 5HIAA, the serotonin metabolite in the extracellular space, almost continuously. Buspirone, 2.5 mg/kg i.p. was ineffective, but the dose of 10 mg/kg lowered 5HIAA between about 45 and 150 min; the same decrease was obtained with 40 mg/kg. This effect can be explained by an agonistic action on 5HT1 A receptors. The metabolite 1PP, which displays alpha 2 adrenoceptor blocking properties, either had no effect or raised extracellular 5HIAA, depending on the dose (1.5 or 6 mg/kg). The rapid metabolization of buspirone to 1PP can thus explain the short time course of the drug effect. Pretreatment with 1PP could only partially prevent buspirone's effect on the serotoninergic system.