At there ambient air temperature range, the rectal temperature changes following infusion of histamine either into lateral ventricle (L.V.) or IVth ventricle (IVth V) were studied. At an ambient temperature range of 19-22 degrees C, hypothermia occurred following histamine infusion either into L.V. or IVth V. Hypothermia elicited from infusion of histamine into L.V. was prevented with pretreatm...

BACKGROUND Information related to histamine-induced cellular responses in C6 glioma cells through second messenger pathways has not been fully studied, especially the involvement of arachidonic acid (AA) metabolism. In addition, specific labeled ligand binding to histamine receptor sites still needs to be clarified. METHODS Labeled mepyramine ligand was used to study its binding sites; [(3)H]...

It has been reported that antihistamines do not fully modify symptoms of allergic conjunctivitis in clinical settings, suggesting that histamine is not the only contributor to symptom generation in the disease. However, in the majority of experimental allergic conjunctivitis models, antihistamines are very effective in the reduction of symptoms. In the present study, we used our recently develo...

Species isoforms of histamine H2-, H3-, and H4-receptors differ in their pharmacological properties. The study aim was to dissect differences between the human H1R (hH1R) and guinea pig H1R (ghH1R). We coexpressed hH1R and gpH1R with regulators of G-protein signaling in Sf9 insect cells and analyzed the GTPase activity of Gq-proteins. Small H1R agonists showed similar effects at hH1R and gpH1R,...

Premedication with a combination of histamine H₁ receptor (H₁R) and H₂ receptor (H₂R) antagonists has been suggested as a prophylactic principle, for instance, in anaesthesia and surgery. Aiming at pharmacological hybrids combining H₁R and H₂R antagonistic activity, a series of cyanoguanidines 14-35 was synthesized by linking mepyramine-type H₁R antagonist substructures with roxatidine-, tiotid...