Chloroquine-Induced Itch Model

The chloroquine-induced itch model in mice is an acute, histamine-independent pruritus model. An intradermal injection of chloroquine activates MrgprA3 (Mas-related G-protein-coupled receptor A3) on a subset of peripheral sensory neurons. Signaling through TRPA1 then triggers sensory-neuron activation and a strong, measurable scratching response.

Scratch duration and scratch frequency totals
Bar chart of scratch duration totals (seconds) for three groups: saline SC/saline ID, saline SC/chloroquine ID and U-50488 SC/chloroquine ID, with significance brackets between groups. Bar chart of scratch frequency totals (counts) for the same three groups, with significance brackets between groups.

Saline SC/saline ID, saline SC/chloroquine ID and U-50488 SC/chloroquine ID groups.