Table 5 H4 Receptor Antagonists
From: The Role of Antihistamines in the Treatment of Vasomotor Rhinitis
Receptor | H4 |
|---|---|
Signal conduction through | Gi/o and G15/16 |
Location of receptors | Eosinophils, neutrophils, basophils, mast cells, spleen, liver, lung colon, epicanthus, and bone marrow |
Chromosome location | 18q11.2 |
Signal conduction induces | Decreased cyclic AMP, MAP kinase induction, phospholipase C activation, formation of diacylglycerol, calcium mobilization |
Antagonists (reverse agonists) | None available clinically: Has homology with H3 receptor and is also antagonized by same drugs |
Activities | Chemotaxis and chemokinesis of mast cells and eosinophils; enhancement of the activity of other chemoattractants (eg, chemokines) on eosinophils; upregulation of adhesion molecules |
Nasal symptoms produced | Since histamine can up regulate inflammation on cells such as eosinophils, H4 antagonists may have a beneficial role in this regard |