The pronociceptive effect of proteinase-activated receptor-4 stimulation in rat knee joints is dependent on mast cell activation

Proteinase-activated receptor-4 (PAR4) is a G-protein-coupled receptor activated by serine proteinases released during tissue repair and inflammation. We have previously shown that PAR4 activation sensitises articular primary afferents leading to joint pain. This study examined whether mast cells contribute to this PAR4-induced sensitisation and consequent heightened pain behaviour. The expression of PAR4 on synovial mast cells was confirmed...