Amthamine

Olanzapine and haloperidol were obtained from FUJIFILM Wako Pure Chemical Corporation (Osaka, Japan). Dopamine hydrochloride and bromocriptine were purchased from Sigma-Aldrich (St Louis, MO, USA). 7-Hydroxy PIPAT, ABT724, TCB2, BW723C86, Ro60–0175, WAY181187, 2-PEA, NGB2904, sonepiprazole, MDL11939, SB204741, SB399885, trans-triprolidine, amthamine, and tiotidine were from Tocris Bioscience (Bristol, England, UK). SB242084 was obtained from Toronto Research Chemicals (Ontario, Canada). All other chemicals used were of the highest purity available.

The following histamine receptor ligands and stimuli were used in this study: histamine (ALK‐Abello, Madrid, Spain) as agonist for all histamine receptors; 2‐pyridylethylamine (Tocris Bioscience, Bristol, UK) as selective H1 receptor agonist; amthamine (Tocris Bioscience, Bristol, UK) as selective H2 receptor agonist; 4‐methylhistamine as a H2 /H4 receptor agonist; ST‐1006 (Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Duesseldorf, Germany) as H4 receptor agonist (Sander et al., 2009); clemastine (Tocris) as selective H1 receptor antagonist; ranitidine (Tocris) as selective H2 receptor antagonist; and JNJ7777120 (Sigma Aldrich, Deisenhofen, Germany) as selective H4 receptor antagonist. All histamine receptor ligands were used at a concentration of 10 μM. In concentration–response experiments, the histamine receptor ligands were used in the range of 0.1 ‐ 100 μM. In extensive previous studies, we have shown that 10 μM is the optimal concentration to demonstrate and reproduce robust H4 receptor agonist mediated effects (Gschwandtner, Koether, Werfel, Stark, & Gutzmer, 2013). C5a (10 ng·ml−1; Sigma, Deisenhofen, Germany); recombinant human rh OSM (1 ng·ml−1) ImmunoTools, Friesoythe, Germany); GM‐CSF (10 ng·ml−1), IFN‐γ (200 ng·ml−1) (R&D, San Diego, CA, USA); LPS (50 ng·ml−1) Sigma Aldrich.

The following histamine receptor ligands were used in this study: Histamine (ALK-Abello, Madrid, Spain) as agonist for all histamine receptors; 2-pyridylethylamine (Tocris Bioscience, Bristol, UK) as selective H1R agonist; amthamine (Tocris Bioscience, Bristol, UK) as selective H2R agonist; ST-1006 (Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Duesseldorf, Germany) as H4R agonist [21 (link)]; ranitidine (Sigma Aldrich, Deisenhofen, Germany) as selective H2R antagonist. JNJ7777120 (Sigma Aldrich, Deisenhofen, Germany) as selective H4R antagonist. All histamine receptor ligands were used at a concentration of 10 µM. In extensive previous studies we could show that the concentration of 10 µM is optimal to demonstrate and reproduce robust histamine receptor ligand mediated effects [22 (link)].