Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05231 (interleukin-6)
 23,907 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent animal and human studies have suggested that leptin secretion is closely linked to the functions of the hypothalamic-pituitary-adrenal (HPA) axis and the immune system, both of which are crucial in influencing the course and outcome of critical illness. Therefore, we measured basal plasma leptin levels and examined the circadian secretion of leptin, in parallel with the hormones of the HPA axis and a key cytokine, interleukin-6, in critically ill patients with acute sepsis. Sixteen critically ill patients from the University of Leipzig Intensive Care Unit were recruited for this study. All of these patients fulfilled the standard diagnostic criteria for sepsis. Plasma leptin levels were measured in all patients and controls at 09:00. In addition, in a subgroup of eight critically ill patients and all of the nine controls plasma leptin, cortisol, ACTH and interleukin-6 concentrations were measured every 4 hours for 24 hours. Mean plasma leptin levels were three-fold higher (18.9 +/- 4.5 ng/ml) in critically ill patients than controls (3.8 +/- 1.0 ng/ml, p < 0.05). Similarly, ACTH levels were lower (7.8 +/- 3.4 pmol/l) in patients than in controls (17.1 +/- 1.5 pmol/l, p < .001), while plasma cortisol levels were increased (947.6 +/- 144 nmol/l) in patients compared to controls (361.1 +/- 29, p < 0.001). Morning plasma interleukin-6 levels were markedly elevated in all patients with sepsis (1238.0 +/- 543.1 pg/ml) versus controls (6.4 +/- 1.7, p < 0.001). The controls exhibited a nyctohemeral fluctuation in plasma leptin levels with peak levels at 23:00; in contrast, septic patients, had no nocturnal rise of leptin. In healthy controls, plasma leptin and cortisol had reciprocal circadian rhythms with high nocturnal leptin levels and low nocturnal cortisol concentrations; in critically ill patients, this relation was abolished. Mean leptin levels were three-fold higher in patients who survived the septic episode (25.5 +/- 6.2, n = 10) than in non-survivors (8.0 +/- 3.7, n = 6, p < 0.01). We conclude that in addition to its function as an anti-obesity factor, leptin may play a role in a severe stress state such as acute sepsis.
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PMID:Plasma leptin levels are increased in survivors of acute sepsis: associated loss of diurnal rhythm, in cortisol and leptin secretion. 943 56

We have previously shown that daily injection of alcohol for 3 days induced a significant and long-lasting blunting of the hypothalamic-pituitary-adrenal (HPA) axis response to a subsequent treatment with this drug. The fact that, in contrast, the HPA axis response to footshocks was not altered by prior alcohol administration, suggested the presence of a phenomenon of selective neuroendocrine tolerance. To further test this hypothesis, we determined whether an initial alcohol challenge would alter the ACTH response to immune signals, such as interleukin-1beta (IL-1beta) and/or endotoxin (lipopolysaccharide; LPS). Because of the functional connection between the HPA axis and immune responses, we also determined whether the LPS-induced release of tumor necrosis factor-alpha and interleukin-6, as well as IgG and IgM responses to an antigenic challenge, would be influenced by previous exposure to alcohol. We show here that the intragastric injection of 3 g of alcohol/kg daily for 3 days did not significantly alter the ability of IL-1beta (400 ng/kg) or LPS (1 microg/kg), both injected intravenously 7 days later, to release ACTH. Drug pretreatment did not significantly alter the tumor necrosis factor-alpha response to the low dose of endotoxin used, whereas there was a tendency toward increased circulating interleukin-6 levels in alcohol-pretreated animals. Finally the IgG, but not IgM, response to the antigen phosphocholine-keyhole limpet hemocyanin was significantly (p < 0.05) augmented in rats administered alcohol 7 days before the antigenic challenge. Collectively, these results indicate that an initial exposure to alcohol does not induce long-term changes in the ability of an immune signal (IL-1beta or endotoxin) to activate the HPA axis. In contrast, a small but detectable enhancement of cytokine responses to LPS, and of the IgG response to phosphocholine-keyhole limpet hemocyanin, was observed.
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PMID:Effect of pretreatment with alcohol on subsequent endocrine and immune responses in the adult male rat. 943 31

Interleukin-6 (IL-6) is a proinflammatory cytokine that has been shown to mediate, in addition to immune reactions, various endocrine and central nervous components of the acute phase response. In this context, the present study aimed to specify the contributions of IL-6 to the regulation of pituitary-adrenal secretory activity and GH and TSH secretion, as well as to the regulation of central nervous sleep and mood in healthy men. Effects of a low dose of IL-6 (0.5 microgram/kg body weight) were assessed, inducing plasma IL-6 concentrations closely comparable with those typically observed after infectious challenge. Each of the 16 male subjects participated in two 14-h sessions (between 1800 and 0800 h), receiving either placebo or human recombinant IL-6 sc at 1900 h. Blood was collected repeatedly to determine plasma hormone levels, serum concentrations of cytokines, and C-reactive protein. Moreover, mood was assessed, and sleep recordings were obtained between 2300 and 0700 h. The cytokine induced a prolonged increased in plasma concentrations of ACTH and cortisol (P < 0.001), but led to a decrease in TSH concentrations (P < 0.01). In response to IL-6, subjects reported fatigue and felt more inactive and less capable of concentrating than after placebo. Sleep architecture was altered significantly by the cytokine. Slow-wave sleep was decreased during the first half and increased during the second half of sleep. Rapid eye movement sleep during the entire nocturnal sleep time was significantly decreased. After IL-6, body temperature rose slightly. C-reactive protein concentrations were dramatically increased 12.5 h after substance administration (P < 0.001). IL-6 did not affect serum concentrations of IL-2, IL-8, interferon-alpha, and interferon-gamma. The results underscore the importance of IL-6 in the cascade of cytokines for the neuroendocrine response during the acute phase reaction. In addition, IL-6 appears to be involved in changes of sleep and behavior accompanying infection and inflammatory disorders.
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PMID:Acute effects of recombinant human interleukin-6 on endocrine and central nervous sleep functions in healthy men. 958 58

Immune stimulation increases the activity of the HPA axis, a phenomenon directly or indirectly mediated through cytokines. We have used two models, the peripheral administration of endotoxin (LPS) or turpentine-induced tissue injury to show that corticotropin-releasing factor (CRF) and vasopressin (VP), hypothalamic peptides released by cytokines, play a dominant role in the increased ACTH measured in these two paradigms. In turn, CRF and VP synthesis and/or release is modulated by catecholamines, prostaglandins (PGs), and nitric oxide (NO). These secretagogues are produced in the periphery and/or the central nervous system (CNS) in response to increased cytokine levels and act on CRF/VP neurons and nerve terminals. Finally, endotoxemia and local tissue inflammation may upregulate brain levels of tumor necrosis factor alpha, interleukin-1 beta, and/or interleukin-6, providing yet another mechanism through which the occurrence of systemic inflammation is conveyed to the brain. The relative importance of brain or peripheral intermediates appears to depend on the site at which cytokine levels are increased. We have shown, for example, that peripheral, but not brain, PGs are important in mediating the neuroendocrine influence of blood-borne cytokines, while PGs in the CNS play a role in situations characterized by elevated brain immune proteins. NO, on the other hand, restrains the response of the HPA axis to circulating, but not brain cytokines. These results illustrate the complexity of the mechanisms involved in the stimulation of the HPA axis and suggest that their specific involvement depends on the type, intensity, and duration of immune stimulation.
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PMID:Mechanisms of hypothalamic-pituitary-adrenal axis stimulation by immune signals in the adult rat. 962 70

Interleukin-6 (IL-6) is one of several cytokines that can stimulate the hypothalamo-pituitary-adrenocortical (HPA) axis. Because IL-6 is produced in response to the administration of endotoxin (LPS) and interleukin-1 (IL-1), it is possible that IL-6 contributes to the neuroendocrine and neurochemical changes induced by them. In this study, intraperitoneal (i.p.) injection of LPS elevated plasma concentrations of IL-6 while activating the HPA axis in a dose-dependent manner. Both responses reached a peak at around 2-3 h. Mouse IL-1beta administration (100 ng, i.p.) induced large increases in plasma corticosterone and a substantial, but short-lived increase in plasma IL-6 with a peak at 2 h. Pretreatment of mice intraperitoneally with a monoclonal antibody to mouse IL-6 significantly attenuated the plasma ACTH and corticosterone responses to LPS at 3 h, but not at 1 h. Anti-IL-6 treatment also attenuated the LPS-induced increases of tryptophan and the serotonin catabolite, 5-hydroxyindoleacetic acid (5-HIAA), but not that of the norepinephrine catabolite, 3-methoxy,4-hydroxyphenylethyleneglycol (MHPG). Pretreatment of mice with anti-IL-6 significantly attenuated the IL-1-induced increases of plasma ACTH and corticosterone at 2 h, but not at 4 h. The IL-1-induced increases of MHPG, tryptophan and 5-HIAA in hypothalamus and brain stem were not significantly altered. These results suggest that IL-6 contributes to the later phases of the LPS- and IL-1-induced stimulations of the HPA axis and to the indoleaminergic responses to LPS, but not to IL-1.
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PMID:The role of interleukin-6 in the activation of the hypothalamo-pituitary-adrenocortical axis and brain indoleamines by endotoxin and interleukin-1 beta. 987 16

To evaluate whether interferon-gamma (IFN-gamma) is involved in the interaction between the immune and endocrine systems in vivo, we studied six healthy subjects twice in a placebo-controlled trial: once after administration of recombinant human IFN-gamma and, on another occasion, after administration of saline. The rate of appearance of glucose was determined by infusion of [6,6-2H2]glucose and resting energy expenditure by indirect calorimetry. Human leukocyte antigen-DR gene expression on monocytes and serum neopterin increased after administration of IFN-gamma (P < 0.05 vs. control). IFN-gamma increased serum interleukin-6 levels significantly. Levels of tumor necrosis factor-alpha remained below detection limits. IFN-gamma increased plasma concentrations of ACTH and cortisol (P < 0.05 vs. control), IFN-gamma did not alter concentrations of growth hormone, (nor)epinephrine, insulin, C peptide, glucagon, or insulin-like growth factor I. IFN-gamma did not alter plasma concentrations of glucose and free fatty acids nor the rate of appearance of glucose. IFN-gamma increased resting energy expenditure significantly. We conclude that IFN-gamma is a minor stimulator of the endocrine and metabolic pathways. Therefore, IFN-gamma by itself is probably not a major mediator in the interaction between the immune and the endocrine and metabolic systems.
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PMID:Interferon-gamma has immunomodulatory effects with minor endocrine and metabolic effects in humans. 993 Nov 85

The consequences of glucocorticoid receptor (GR) dysfunction for neuroimmunoendocrine responses to an inflammatory challenge were studied in transgenic mice expressing antisense RNA directed against the GR [GR-impaired (GR-i) mice]. Mice were implanted intraperitoneally with a biotelemetry transmitter to monitor body temperature and locomotion. GR-i mice showed decreased locomotion and body temperature during the dark phase of the diurnal cycle. Intraperitoneal administration of saline caused a rapid increase in body temperature in control mice, which was terminated within 90 min. In GR-i mice, however, body temperature remained elevated for about 6 h. Intraperitoneal injection of endotoxin (10 micrograms/mouse) produced a biphasic fever in control mice. However, in endotoxin-injected GR-i mice, body temperature was not significantly different from their saline-injected controls during the first 6 h. Body temperature then increased and remained elevated during the night period. Both strains showed hypolocomotion after endotoxin. In a second experiment, mice were injected intraperitoneally with saline or endotoxin and killed after 1, 3, 6 or 24 h. In GR-i mice, endotoxin caused an augmented rise in plasma ACTH, but not in corticosterone levels. The endotoxin-induced increase in serum levels of interleukin-1 beta and interleukin-6 was not different between the strains. However, whereas in control mice tumour necrosis factor-alpha levels were below detection at the time points studied, substantial levels of this cytokine were found in the serum of GR-i mice 1 h after endotoxin administration. It may be concluded that life-long impairment of GR evolves in aberrant physiological and humoral responses to an acute inflammatory challenge. These findings expand our understanding about the neuroendocrine and physiological disturbances associated with stress-related disorders.
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PMID:Impaired glucocorticoid receptor function evolves in aberrant physiological responses to bacterial endotoxin. 998 22

This study investigated the effects of acute alcohol pretreatment on endotoxin lipopolysaccharide (LPS)-induced release of ACTH, corticosterone, and pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in plasma and at various tissues sites. Specifically, we wanted to determine whether alcohol pretreatment would alter the ACTH, corticosterone, and cytokine responses to LPS, and whether the alcohol-induced changes in ACTH/corticosterone secretory rates of endotoxemic rats were accompanied by similar changes in cytokine production. Alcohol, 3.0 g/kg, intragastric (i.g.), was administered 3 hr before LPS treatment [1.0 or 5.0 microg/kg, intravenous (i.v.)], and ACTH, corticosterone, and cytokines levels were measured over a 4 hr post LPS treatment. In intact rats, the alcohol-induced plasma ACTH and corticosterone responses had returned to basal levels by the time of LPS injection, and alcohol pretreatment increased the corticosterone but not the ACTH response after LPS treatment. In contrast, in adrenalectomized corticosterone-replaced animals, the alcohol-induced ACTH response was still elevated at the time of LPS injection. However, the overall ACTH response of rats pretreated with the vehicle or alcohol was statistically similar. As expected, LPS also significantly stimulated both TNF-alpha and IL-6 release into the general circulation. The IL-6, but not the TNF-alpha, response was inhibited by alcohol pretreatment in intact rats, a phenomenon that was not present in adrenalectomized animals. Finally, we showed that LPS also augmented the TNF-alpha and/or IL-6 content of the pituitary, adrenal glands, and spleen, and that these responses were not altered by alcohol pretreatment. On the basis of these results, we concluded that acute alcohol treatment increased LPS-induced corticosterone response, while it blunted the IL-6 response. LPS also significantly elevated pituitary, adrenal, and splenic contents of TNF-alpha and IL-6, and alcohol did not influence these changes.
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PMID:Effect of acute alcohol treatment on the release of ACTH, corticosterone, and pro-inflammatory cytokines in response to endotoxin. 1023 3

We experienced four cases with hyponatremia due to SIADH, which seems to be related to inflammation. The plasma Na concentration decreased when the patients had fever and increased plasma CRP level. In such conditions, plasma vasopressin concentration (PAVP) and the plasma interleukin-6 (IL-6) concentration were increased. There was significant correlation between them. The animal experiments were carried out to investigate the role of interleukin in the development of SIADH. Intravenous administrations of IL-1 beta increased AVP, atrial natriuretic hormone (ANH) and ACTH. The changes in AVP and ACTH were abolished by the pretreatment with an intravenous administration of indomatacin. Moreover, the intracerebroventricular administration (ICV) of IL-1 beta also increased AVP, atrial natriuretic hormone (ANH) and ACTH. The pretreatment of indomatacin attenuated the changes in AVP and ACTH. The intravenous administration of IL-1 beta increased the urinary sodium excretion. The pretreatement of HS142-1, an ANH antagonist, abolished the increase in urinary sodium excretion induced by IL-1 beta. These results suggested that the interleukin play an important role in the development of SIADH associated with inflammation.
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PMID:[Hyponatremia and inflammation]. 1037 61

Interleukin-6 (IL-6) is a proinflammatory cytokine that plays multiple roles in the central nervous system during infections and injuries. Although this molecule is capable of stimulating the release of ACTH and glucocorticoids, it has been demonstrated that a single injection of IL-6 fails to activate the paraventricular nucleus (PVN) neurons that control the hypothalamic-pituitary-adrenal axis. The observation that IL-6 receptor (IL-6R) is up-regulated in the brain during endotoxemia led us to hypothesize that prior induction of IL-6R synthesis could amplify the effect of circulating IL-6 on the neuroendocrine response. Rats received a first iv injection of either bacterial lipopolysaccharide (LPS; 5 microg) or vehicle solution. After a 6-h waiting period, they received a second iv injection of either recombinant rat IL-6 or vehicle solution and were killed 1 h thereafter. Using in situ hybridization, we observed that IL-6R was barely expressed in the PVN under basal conditions, but was rapidly produced in response to LPS. IL-6 itself was also able to induce the synthesis of its own receptor along cerebral blood vessels, and this effect extended to several parenchymal structures, including the PVN, when the cytokine was administrated after LPS. In agreement with our hypothesis, we found that IL-6 injected in LPS-pretreated rats stimulated PVN neurons, as revealed by the expression of CRF primary transcript and c-fos messenger RNA, an immediate early gene used as a marker of cellular activation. A significant increase in plasma corticosterone levels was also found in animals that received iv IL-6 injection after being pretreated 6 h before with the very low dose of LPS. The fact that IL-6 alone or injected after LPS treatment was unable to induce cyclooxygenase-2 synthesis is an argument in favor of a PG-independent mechanism. The relative contribution of IL-6 in stimulating CRF expression in the PVN and neural activity throughout the brain during endotoxemia was also investigated in IL-6-deficient mice after an ip injection of LPS. The endotoxin induced similar c-fos and CRF expression patterns in knockout and wild-type mice, but the expression levels were generally higher and/or lasted longer in wild-type animals. Taken together, physiological changes that may include the induction of IL-6R synthesis seem to be necessary for IL-6 to activate PVN neurons. Moreover, although IL-6 does not appear essential during the early phases of endotoxemia, this cytokine is required during the later phases to prolong the activation of neural cells throughout the brain and to maintain CRF expression in the PVN neurons that control the hypothalamic-pituitary-adrenal axis.
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PMID:Interleukin-6 is a needed proinflammatory cytokine in the prolonged neural activity and transcriptional activation of corticotropin-releasing factor during endotoxemia. 1046 57


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