TRPV1 and PLC Participate in Histamine H4 Receptor-Induced Itch

Figure 1

H4 receptor agonist immepip induced an increase in of the DRG neuron. (a) Representative traces of DRG response to H4 agonist 50 μM immepip twice in 5 min interval. (b) Venn diagram of cell shows the proportion of immepip-response DRG neuron in total test neurons. (c) Histograms show that the DRG neuron exhibited a concentration-dependent increase in response to 8.3, 16.7, and 50 μM immepip stimulation. (d, e, f, and g) Representative neurons response to 50 μM immepip and 50 μM histamine, (d) control, (e) neuron 2 increase in by application of immepip, (f) washout, and (g) neurons 1 and 2 increase in by application histamine. (h) Magnified neuron images of the same neurons in (d–g). Images of Hd1, Hd2 were magnified from neurons 1 and 2 in (d); images of He1, He2 were magnified from neurons 1 and 2 in (e); images of Hf1, Hf2 were magnified from neurons 1 and 2 in (f); images of Hg1, Hg2 were magnified from neurons 1 and 2 in (g). (i) Traces of DRG neurons 1 and 2 from (d–g) response to immepip and histamine; the data show both neuron 1 and neuron 2 respond to histamine (blue line), but only neuron 2 responds to immepip (red line).

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)