1. When isolated perfused lungs from normal and ovalbumin sensitized guinea-pigs were challenged with histamine and 2-methylhistamine (agonists for H1-receptor), a release of thromboxane A2-like substance was observed. The effect of histamine on production of thromboxane A2 (TXA2) in sensitized lungs, was more pronounced than in normal lungs (P less than 0.01). 2. Specific activation of histami...

The precise mechanism(s) underlying the thermal hyperemic response to local heating of human skin are not fully understood. The purpose of this study was to investigate a potential role for H1 and H2 histamine-receptor activation in this response. Two groups of six subjects participated in two separate protocols and were instrumented with three microdialysis fibers on the ventral forearm. In bo...

The possible roles of spinal histamine receptors in the regulation of the blood glucose level were studied in ICR mice. Mice were intrathecally (i.t.) treated with histamine 1 (H1) receptor agonist (2-pyridylethylamine) or antagonist (cetirizine), histamine 2 (H2) receptor agonist (dimaprit) or antagonist (ranitidine), histamine 3 (H3) receptor agonist (α-methylhistamine) or antagonist (carcini...

Statins have been widely used for the treatment of a variety of medical conditions including psychoneurological disorders beyond their original use in lowering cholesterol. Histamine receptors play an important role in the regulation of neural activity, however, it is unknown whether statins act on histamine receptors, particularly for their neural regulatory effects. This study examined the ef...

Exercise-induced arterial hypoxemia (EIAH) in human subjects may be associated with pulmonary injury/capillary stress failure-induced histamine release and is reported to be ameliorated by administration of H1 antihistiminics. EIAH is a routine occurrence in strenuously exercising Thoroughbreds, 75–100% of which also experience exercise-induced pulmonary hemorrhage (EIPH). In contrast with repo...

Intravenous histamine causes high amplitude repetitive phasic contractions of the in vivo cat pylorus but has little effect on the antrum and duodenum. The genesis of this phasic response was studied using a pinned perfused catheter with openings at the pylorus, antrum, and duodenum. 2-Pyridylethylamine, an H1 agonist, produced phasic contractions similar to histamine whereas dimaprit, an H2 ag...

In the present study, effects of intracerebroventricular (icv) administration of histamine, mepyramine (H1-receptor antagonist) and famotidine (H2-receptor antagonist) have been investigated on the formalin test in rats. Subcutaneous injection of formalin (50 microl, 1%) into the ventral surface of the left hind paw produced a marked biphasic pain response (first phase: 0-5 min and second phase...

Abbreviations: A1R: Adenosine A1 Receptor; A2AR: Adenosine A2A Receptor; A2BR: Adenosine A2B Receptor; A3R: Adenosine A3 Receptor; Cpd: Compound; D2R: Dopamine D2 Receptor; Emax: Efficacy; gp: Guinea-pig; GPCR: G-Protein Coupled Receptor; h: Human; H1R: Histamine H1 Receptor; H3R: Histamine H3 Receptor; r: rat; 5-HT1AR: Serotonine 5-HT1A Receptor; βR: β-Adrenergic Receptors; β2R: Adrenergic β2 ...

BACKGROUND Histamine can induce coronary vasospasm, leading to variant angina and acute myocardial infarction. However, the role of histamine in thrombus formation is ill defined. Hence, this study investigates whether histamine induces tissue factor (TF) expression in vascular cells. METHODS AND RESULTS Histamine (10(-8) to 10(-5) mol/L) induced TF expression in a concentration-dependent man...