Gγ
Gβ
Phospholipase
C, beta 1
Inositol 1,4,5-
trisphosphate
receptor type 1
protein kinase
C beta
Nuclear factor
NF-kappa-B p105
subunit
Gγ
Histamine H1
receptor
Gαq
Gαq
Histamine H1
receptor
Gβ
Histamine
Inositol 1,4,5-
trisphosphate
Ca+
Chlorpheniramine
Ca+
H2O
Calcium
Calcium
GDP
GTP
Histamine
1,2-Diacyl-
sn-glycerol
phosphatidylinositol
4,5-
bisphosphate
↑ Pro-inflammatory
Cytokines, Cell Adhesion
Molecules, Chemotactic
Factors
Mast Cells
Release
Histamine
Endoplasmic Reticulum
Nucleus
Calcium Ion Channel
Cell Membrane
Cytoplasm
↑ Antigen Presentation
↑ Mediator Release
↓ Mast Cell Stabilization
The GPCR activates the G
protein by exchanging GDP
for GTP. This exchange
triggers the dissociation of
the Gα subunit from the Gβγ
dimer and the receptor.
Blocking the action of
histamine at the H1 receptor
helps to relieve allergic
reactions.