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Contains fulltext : 32642.pdf (Publisher’s version ) (Closed access) In this study the anti-inflammatory properties of zilpaterol, a beta2-adrenergic receptor (AR) agonist specifically developed as a growth promoter in cattle were investigated. Although zilpaterol has a different structure compared with the beta2-AR agonists known to date, it was noted that it was able to bind to both the beta2-AR (Ki = 1.1 x 10(-6)) and the beta1-AR (Ki = 1.0 x 10(-5)). Using lipopolysaccharide (LPS)-exposed U937 macrophages, the production of cyclic adenosine-3',5'-cyclic monophosphate (cAMP) and tumor necrosis factor alpha (TNF-alpha) were investigated. Zilpaterol inhibited TNF-alpha release and induced intracellular cAMP levels in a dose-dependent manner. The inhibition of TNF-alpha release and induction of cAMP production was mainly mediated via the beta2-AR, as indicated by addition of beta1- and beta2-specific antagonists. The effects of zilpaterol were investigated in LPS-treated male Wistar rats after pretreatment with zilpaterol. Zilpaterol dosed at 500 microg/kg body weight reduced the TNF-alpha plasma levels. In conclusion, zilpaterol is a beta2-adrenergic agonist and an inhibitor of TNF-alpha production induced by LPS both in vivo and in vitro.

Pharmacokinetic properties and safety profile of a drug are likely influenced by the disease state of a patient. In this study, we investigated the influence of arthritic processes on pharmacokinetics and immunotoxicity of interleukin-1 receptor antagonist (Anakinra) in the rat adjuvant arthritis model. Anakinra dose-dependently suppressed joint inflammation and degradation as demonstrated by reduced clinical arthritis score, paw thickness, synovial infiltration and bone degradation. In addition, plasma levels of chemokines MCP-1 and GRO/KC were reduced. Pharmacokinetic behaviour of Anakinra was influenced by disease state of the rats as judged from a decrease in Cmax and an increase of the MRT as the disease progressed at a dose of 24 and 72mgAnakinra/kgbody weight. The pharmacokinetic parameters increased dose-dependently, but non-proportionally with increasing dose. Low level anti-Anakinra antibody formation was observed at prolonged exposure to the biologic. Safety parameters, including haematology, splenic lymphocyte subset analysis, ex vivo stimulation of spleen cells and histopathology of immune system organs were affected by the disease itself to such extent that no additional effects of Anakinra could be observed. In conclusion, we demonstrated that pharmacokinetic behaviour of Anakinra was influenced by the arthritis background of the rats resulting in decreased internal exposure. © 2011 Elsevier Inc.

Microbial metabolites may influence the metabolic integrity of intestinal epithelial cells and induce mucosal immune responses. Therefore, we investigated the effects of the microbial metabolites butyrate, iso-valerate, and ammonium on Caco-2 cells and macrophages. Barrier functioning was determined by measuring transepithelial electrical resistance and basolateral recoveries of metabolites. The barrier function of Caco-2 cells remained intact after exposures. Basolateral recoveries ranged from 6.2% to 15.2%. Tumour necrosis factor-α and interleukin-10 were measured to determine immune reactions. The Caco-2 cells did not secrete both cytokines. Physiological concentrations of butyrate and iso-valerate stimulated the secretion of tumour necrosis factor-α and suppressed the secretion of interleukin-10 by macrophages that are not protected by an epithelial barrier. In contrast, ammonium concentrations as high as those produced by microbiotas of IBD patients suppressed the release of both cytokines when the barrier function is impaired. © 2005 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.

In this study the anti-inflammatory properties of zilpaterol, a β2-adrenergic receptor (AR) agonist specifically developed as a growth promoter in cattle were investigated. Although zilpaterol has a different structure compared with the β2-AR agonists known to date, it was noted that it was able to bind to both the β2-AR (K i = 1.1 × 10-6) and the β1-AR (Ki = 1.0 × 10-5). Using lipopolysaccharide (LPS)-exposed U937 macrophages, the production of cyclic adenosine-3′, 5′-cyclic monophosphate (cAMP) and tumor necrosis factor alpha (TNF-α) were investigated. Zilpaterol inhibited TNF-α release and induced intracellular cAMP levels in a dose-dependent manner. The inhibition of TNF-α release and induction of cAMP production was mainly mediated via the β2-AR, as indicated by addition of β1- and β2-specific antagonists. The effects of zilpaterol were investigated in LPS-treated male Wistar rats after pretreatment with zilpaterol. Zilpaterol dosed at 500 μg/kg body weight reduced the TNF-α plasma levels. In conclusion, zilpaterol is a β2-adrenergic agonist and an inhibitor of TNF-α production induced by LPS both in vivo and in vitro. © 2005 Blackwell Publishing Ltd.

Two-dimensional difference gel electrophoresis (DIGE) in combination with univariate (Student's t-test) and multivariate data analysis, principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to study the anti-inflammatory effects of the β2-adrenergic receptor (β2-AR) agonist zilpaterol. U937 macrophages were exposed to the endotoxin lipopolysaccharide (LPS) to induce an inflammatory reaction, which was inhibited by the addition of zilpaterol (LZ). This inhibition was counteracted by addition of the β2-AR antagonist propranolol (LZP). The extracellular proteome of the U937 cells induced by the three treatments were examined by DIGE. PCA was used as an explorative tool to investigate the clustering of the proteome dataset. Using this tool, the dataset obtained from cells treated with LPS and LZP were separated from those obtained from LZ treated cells. PLS-DA, a multivariate data analysis tool that also takes correlations between protein spots and class assignment into account, correctly classified the different extracellular proteomes and showed that many proteins were differentially expressed between the proteome of inflamed cells (LPS and LZP) and cells in which the inflammatory response was inhibited (LZ). The Student's t-test revealed 8 potential protein biomarkers, each of which was expressed at a similar level in the LPS and LZP treated cells, but differently expressed in the LZ treated cells. Two of the identified proteins, macrophage inflammatory protein-1beta (MIP-1β) and macrophage inflammatory protein-1 alpha (MIP-1α) are known secreted proteins. The inhibition of MIP-1β by zilpaterol and the involvement of the β2-AR and cAMP were confirmed using a specific immunoassay. © 2005 American Chemical Society.

Melanocortins (MC), neuropeptides derived from pro-opiomelanocortin, have been implicated in enhancing neurite outgrowth via an as yet unknown mechanism. Recently, five MC receptors have been identified, three of which, the MC3-R, the MC4-R and the MC5-R, are expressed in the nervous system. In this study, -MSH and the melanocortin analog [-Phe7]ACTH (4–10) were able to stimulate neurite outgrowth in the neuroblastoma cell line Neuro 2A. ACTH (4–10), 2-MSH and ORG2766 were inactive. In addition, the MC4-R antagonist [-Arg8]ACTH (4–10), inhibited the -MSH effect, indicating that the MC4-R mediated stimulation of neurite outgrowth by -MSH. Indeed, the presence of MC4-R mRNA in Neuro 2A cells was demonstrated by a RNase protection assay. Heterologous expression of the MC5-R in Neuro 2A cells lead to the recruitment of a responsiveness to 2-MSH, but did not increase the effect of -MSH on neurite outgrowth. This finding indicated that the function of MC4-R can also be exerted by another MC receptor, suggesting that the coupling to Gs, which they have in common, plays an essential role in the neurite outgrowth promoting effect. This was further substantiated by the fact that forskolin treatment per se induced neurite outgrowth in a similar fashion. These data imply that the neurotrophic properties of -MSH are likely to result from Gs-coupled MC receptor activity in neuronal cells.