Basal expression of bradykinin B₁ receptor in peripheral sensory ganglia in the rat

The bradykinin B₁ receptor is thought to be induced by tissue injurY and inflammation. In the present study, we have investigated whether there is a basal expression of B₁ receptor in dorsal root ganglion (DRG) and trigeminal ganglion neurons in rats. A substantial number of neurons in both DRGs and trigeminal ganglia were found to be B₁-immunoreactive in rats. Both small and medium-sized DRG neurons were B₁-immunoreactive, suggesting that they are likely to be Aδ- or C-fibre neurons which are involved in nociceptive transmission. These results support a possible role for B₁ receptors in the modulation of nociceptive sensorY transmission.