Dataset Information

Central Interleukin-1? Suppresses the Nocturnal Secretion of Melatonin.

ABSTRACT: In vertebrates, numerous processes occur in a rhythmic manner. The hormonal signal reliably reflecting the environmental light conditions is melatonin. Nocturnal melatonin secretion patterns could be disturbed in pathophysiological states, including inflammation, Alzheimer's disease, and depression. All of these states share common elements in their aetiology, including the overexpression of interleukin- (IL-) 1? in the central nervous system. Therefore, the present study was designed to determine the effect of the central injection of exogenous IL-1? on melatonin release and on the expression of the enzymes of the melatonin biosynthetic pathway in the pineal gland of ewe. It was found that intracerebroventricular injections of IL-1? (50?µg/animal) suppressed (P < 0.05) nocturnal melatonin secretion in sheep regardless of the photoperiod. This may have resulted from decreased (P < 0.05) synthesis of the melatonin intermediate serotonin, which may have resulted, at least partially, from a reduced expression of tryptophan hydroxylase. IL-1? also inhibited (P < 0.05) the expression of the melatonin rhythm enzyme arylalkylamine-N-acetyltransferase and hydroxyindole-O-methyltransferase. However, the ability of IL-1? to affect the expression of these enzymes was dependent upon the photoperiod. Our study may shed new light on the role of central IL-1? in the aetiology of disruptions in melatonin secretion.

SUBMITTER: Herman AP

PROVIDER: S-EPMC4861797 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Central Interleukin-1β Suppresses the Nocturnal Secretion of Melatonin.

Herman A P AP Bochenek J J Król K K Krawczyńska A A Antushevich H H Pawlina B B Herman A A Romanowicz K K Tomaszewska-Zaremba D D

Mediators of inflammation 20160426

In vertebrates, numerous processes occur in a rhythmic manner. The hormonal signal reliably reflecting the environmental light conditions is melatonin. Nocturnal melatonin secretion patterns could be disturbed in pathophysiological states, including inflammation, Alzheimer's disease, and depression. All of these states share common elements in their aetiology, including the overexpression of interleukin- (IL-) 1β in the central nervous system. Therefore, the present study was designed to determi ...[more]

PMID: 27212805

Similar Datasets

Project description:ObjectivesThe circadian system modulates many important physiologic processes, synchronizing tissue-specific functions throughout the body. We sought to characterize acute alterations of circadian rhythms in critically ill patients and to evaluate associations between brain dysfunction, systemic multiple organ dysfunction, environmental stimuli that entrain the circadian rhythm (zeitgebers), rest-activity rhythms, and the central circadian rhythm-controlled melatonin secretion profile.DesignProspective study observing a cohort for 24-48 hours beginning within the first day of ICU admission.SettingMultiple specialized ICUs within an academic medical center.PatientsPatients presenting from the community with acute onset of either intracerebral hemorrhage as a representative neurologic critical illness or sepsis as a representative systemic critical illness. Healthy control patients were studied in using modified constant routine in a clinical research unit.InterventionsNone.Measurements and main resultsLight, feeding, activity, medications, and other treatment exposures were evaluated along with validated measures of encephalopathy (Glasgow Coma Scale), multiple organ system function (Sequential Organ Failure Assessment score), and circadian rhythms (profiles of serum melatonin and its urinary metabolite 6-sulphatoxymelatonin). We studied 112 critically ill patients, including 53 with sepsis and 59 with intracerebral hemorrhage. Environmental exposures were abnormal, including light (dim), nutritional intake (reduced or absent and mistimed), and arousal stimuli (increased and mistimed). Melatonin amplitude and acrophase timing were generally preserved in awake patients but dampened and delayed with increasing encephalopathy severity. Melatonin hypersecretion was observed in patients exposed to catecholamine vasopressor infusions, but unaffected by sedatives. Change in vasopressor exposure was the only factor associated with changes in melatonin rhythms between days 1 and 2.ConclusionsEncephalopathy severity and adrenergic agonist medication exposure were the primary factors contributing to abnormal melatonin rhythms. Improvements in encephalopathy and medical stabilization did not rapidly normalize rhythms. Urinary 6-sulphatoxymelatonin is not a reliable measure of the central circadian rhythm in critically ill patients.

Project description:ObjectiveThe study examined the effect of intravenous administration of bacterial endotoxin-lipopolysaccharide (LPS) -on the nocturnal secretion of melatonin and on the expression of enzymes of the melatonin biosynthetic pathway in the pineal gland of ewes, taking into account two different photoperiodic conditions: short-night (SN; n = 12) and long-night (LN; n = 12).MethodsIn both experiments, animals (n = 12) were randomly divided into two groups: control (n = 6) and LPS-treated (n = 6) one. Two hours after sunset, animals received an injection of LPS or saline. Blood samples were collected starting one hour after sunset and continuing for 3 hours after the treatment. The ewes were euthanized 3 hours after LPS/saline treatment. The concentration of hormones in plasma was assayed by radioimmunoassay. In the pineal gland, the content of serotonin and its metabolite was determined by HPLC; whereas the expression of examined genes and protein was assayed using real-time polymerase chain reaction and Western Blot, respectively.ResultsEndotoxin administration lowered (p<0.05) levels of circulating melatonin in animals from LN photoperiod only during the first hour after treatment, while in ewes from SN photoperiod only in the third hour after the injection. Inflammation more substantially suppressed biosynthesis of melatonin in ewes from SN photoperiod, which were also characterised by lower (p<0.05) cortisol concentrations after LPS treatment compared with animals from LN photoperiod. In the pineal gland of ewes subjected to SN photoperiod, LPS reduced (p<0.05) serotonin content and the expression of melatonin biosynthetic pathway enzymes, such as tryptophan hydroxylase and arylalkylamine-N-acetyltransferase. Pineal activity may be disturbed by circulating LPS and proinflammatory cytokines because the expression of mRNAs encoding their corresponding receptors was determined in this gland.ConclusionThe present study showed that peripheral inflammation reduces the secretion of melatonin, but this effect may be influenced by the photoperiod.

Dataset Information

Central Interleukin-1? Suppresses the Nocturnal Secretion of Melatonin.

Publications

Central Interleukin-1β Suppresses the Nocturnal Secretion of Melatonin.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets