neuropeptide-y and Sepsis

Topics: Acute-Phase Proteins; Animals; Animals, Newborn; Blood Proteins; Cells, Cultured; Female; Interleukin-18; Matrix Metalloproteinase 14; Neuropeptide Y; Proteome; Sepsis; Staphylococcal Infections; Staphylococcus epidermidis; Swine

The mechanisms involved in septic anorexia are mainly related to the secretion of inflammatory cytokines. The term endozepines designates a family of neuropeptides, including the octadecaneuropeptide (ODN), originally isolated as endogenous ligands of benzodiazepine receptors. Previous data showed that ODN, produced and released by astrocytes, is a potent anorexigenic peptide. We have studied the effect of sepsis by means of a model of cecal ligation and puncture (CLP) on the hypothalamic expression of endozepines (DBI mRNA and protein levels), as well as on the level of neuropeptides controlling energy homeostasis mRNAs: pro-opiomelanocortin, neuropeptide Y, and corticotropin-releasing hormone. In addition, we have investigated the effects of two inflammatory cytokines, TNF-α and IL-1β, on DBI mRNA levels in cultured rat astrocytes.. Studies were performed on Sprague-Dawley male rats and on cultures of rat cortical astrocytes. Sepsis was induced using the CLP method. Sham-operated control animals underwent the same procedure, but the cecum was neither ligated nor incised.. Sepsis caused by CLP evoked an increase of DBI mRNA levels in ependymal cells bordering the third ventricle and in tanycytes of the median eminence. CLP-induced sepsis was also associated with stimulated ODN-like immunoreactivity (ODN-LI) in the hypothalamus. In addition, TNF-α, but not IL-1β, induced a dose-dependent increase in DBI mRNA in cultured rat astrocytes. An increase in the mRNA encoding the precursor of the anorexigenic peptide α-melanocyte stimulating hormone, the pro-opiomelanocortin, and the corticotropin-releasing hormone was observed in the hypothalamus.. These results suggest that during sepsis, hypothalamic mRNA encoding endozepines, anorexigenic peptide as well as stress hormone could play a role in the anorexia/cachexia associated with inflammation due to sepsis and we suggest that this hypothalamic mRNA expression could involve TNF-α.

Topics: Animals; Anorexia; Corticotropin-Releasing Hormone; Diazepam Binding Inhibitor; Disease Models, Animal; Hypothalamus; In Vitro Techniques; Inflammation; Interleukin-18; Ligands; Male; Neuropeptide Y; Neuropeptides; Peptide Fragments; Pro-Opiomelanocortin; Rats; Rats, Sprague-Dawley; Receptors, GABA-A; Sepsis; Tumor Necrosis Factor-alpha

Septic patients always develop muscle wasting, which delays the rehabilitation and contributes to the increased complications and mortality. Previous studies have implied the crucial role of central inflammation and neuropeptides in the energy balance and muscle metabolism. Insulin has been confirmed to attenuate muscle degradation and inhibit inflammation. We tested the hypothesis whether insulin ameliorating muscle wasting was associated with modulating hypothalamic inflammation and neuropeptides.. Thirty-two adult male Sprague-Dawley rats were in intraperitoneally injected with lipopolysaccharide (LPS) (5 mg/kg) or saline, followed by subcutaneous injection of insulin (5 IU/kg) or saline. Twenty-four hours after injection, skeletal muscle and hypothalamus tissues were harvested. Muscle wasting was measured by the mRNA expression of two E3 ubiquitin ligases, muscle ring finger 1 (MuRF-1) and muscle atrophy F-box (MAFbx), as well as 3-methylhistidine (3-MH) and tyrosine release. Hypothalamic inflammatory markers and neuropeptides expression were also measured in four groups.. LPS injection led to significant increase in hypothalamic inflammation as well as muscle wasting. Also, increased hypothalamic neuropeptides, proopiomelanocortin (POMC), cocaine and amphetamine-related transcript (CART) and neuropeptides Y (NPY) and decreased agouti-related protein (AgRP) were observed. Insulin treatment ameliorated endotoxaemia-induced muscle wasting and hypothalamic inflammation, and attenuated the alteration of neuropeptides, POMC, CART and AgRP.. Hypothalamic inflammation and neuropeptides are involved in the endotoxaemia-induced muscle wasting. Insulin treatment can reduce muscle wasting, which is associated with reduced hypothalamic inflammation and alteration of hypothalamic neuropeptides.

Topics: Agouti-Related Protein; Animals; Cytokines; Disease Models, Animal; Endotoxemia; Gene Expression Regulation; Hypothalamus; Inflammation; Insulin; Lipopolysaccharides; Male; Muscles; Neuropeptide Y; Neuropeptides; Pro-Opiomelanocortin; Rats; Rats, Sprague-Dawley; Sepsis; Wasting Syndrome

Loss of appetite occurs in the cecal ligation and puncture (CLP) model of sepsis in conjunction with the activation of central neural stress pathways. Neuropeptide Y (NPY) in the arcuate nucleus of the hypothalamus is upregulated by several stressors and is stimulatory to feeding. To examine the response of NPY messenger RNA in the arcuate nucleus to sepsis, we used biotinylated RNA probes and a quantitative non-isotopic in situ hybridization approach in cryo-preserved sections from rats made septic by CLP. The mRNA in arcuate neurons was upregulated from the first day after CLP. By the afternoon of the third day through the morning of the fourth day, the average grey level of NPY mRNA clusters was 30% greater after CLP than after sham surgery (P<0.05), and the integrated optical density based on both the grey level and the amount of area with detectable mRNA was 60% greater after CLP than after sham surgery (P<0.03). Both the average grey level and area with detectable staining were positively correlated to plasma ACTH (r=0.953 and 0.917, respectively, n=10 and P<0.01 in each case). Thus sepsis increases the expression of the mRNA for NPY in the arcuate nucleus in proportion to the magnitude of the stress response. However, the suppression of feeding behavior in the CLP model suggests that sepsis activates additional mechanisms that negate the orexigenic contribution of the neuronal increase in NPY mRNA.

Topics: Adrenal Cortex; Adrenal Cortex Hormones; Adrenocorticotropic Hormone; Animals; Appetite; Arcuate Nucleus of Hypothalamus; Disease Models, Animal; Feeding Behavior; Male; Neurons; Neuropeptide Y; Rats; Rats, Sprague-Dawley; RNA, Messenger; Sepsis; Stress, Physiological; Up-Regulation

The aim of this work was to study the hypothesis that the release of vasoactive neuropeptides may be related to the hemodynamic changes and severity of disease in human sepsis and septic shock. Twenty-two patients diagnosed with sepsis and treated in medical wards with standard supportive therapy and twenty patients admitted to a medical intensive care unit because of septic shock were studied Twenty healthy volunteers in a similar age range were enrolled as control group. Blood samples were taken at onset and every 12 hours on the following day after hospital admission to measure plasma concentrations of calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and substance P (SP). Clinical and biochemical variables were measured simultaneously. The Acute Physiology and Chronic Health Evaluation (APACHE) II score was calculated on admission. From the day of admission, septic shock patients had significantly higher plasma CGRP-like immunoreactivity levels than patients with sepsis, as well as both groups of patients compared to control subjects. Plasma NPY-like immunoreactivity levels in patients with either sepsis or septic shock was significantly increased, and plasma SP-like immunoreactivity levels significantly reduced compared to those in controls. Plasma CGRP levels at study entry correlated with the APACHE II score (r = 0.71, p < 0.01), as well as with the cardiac index (r = 0.61, p < 0.05) and systemic vascular resistance index (r = -0.62, p < 0.05). Our data suggest that both CGRP and NPY, but not SP, are increasedly released into the circulation during the development of human sepsis and septic shock. In patients with sepsis the vasoconstriction mediated by the release of NPY appears to counterbalance the vasodilatory effect of CGRP. In septic shock patients, however, the release of NPY might be inadequately low to overcome the widespread CGRP-induced vasodilation.

Topics: Adult; Aged; Aged, 80 and over; Calcitonin Gene-Related Peptide; Female; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Hemodynamics; Humans; Male; Middle Aged; Neuropeptide Y; Neuropeptides; Reference Values; Sepsis; Shock, Septic; Substance P

This study in conscious normotensive rats was performed to assess the effect of the vasoconstrictor peptide, neuropeptide Y (NPY), on blood pressure responsiveness to exogenous norepinephrine in endotoxaemia. NPY and endotoxin were infused at doses which had no effect on blood pressure, whether given alone or in combination. Endotoxin markedly reduced the pressor responses to bolus injections of norepinephrine. However, blood pressure responsiveness could be enhanced by infusing NPY simultaneously with the endotoxin. It is suggested that low dose NPY infusions may be clinically useful in reversing the reduced vascular responsiveness to pressor amines in shock.

Topics: Adrenal Medulla; Animals; Blood Pressure; Dose-Response Relationship, Drug; Endotoxins; Infusions, Intravenous; Male; Neuropeptide Y; Norepinephrine; Rats; Rats, Inbred Strains; Sepsis