Release of substance P from peripheral nerve terminals following electrical stimulation of the sciatic nerve.
Substance P is a putative mediator of neurogenic inflammation, where it is postulated to be released from nerve terminals in the skin in response to noxious and electrical stimulation. To demonstrate release of substance P from cutaneous nerve terminals a blister model has been established. Electrical stimulation of the sciatic nerve for 20 min at 50 V, 15 Hz, 0.5 ms, resulted in a significant increase in substance P-like immunoreactivity (SPLI) in blister fluid, which was abolished after neonatal pretreatment of rats with capsaicin. There was no increase of SPLI, following stimulation of the sciatic nerve at 4 V. There was a corresponding decrease in skin SPLI following nerve stimulation at 50 V. Characterization of blister fluid SPLI after stimulation at 50 V demonstrated a peak of immunoreactivity, which co-eluted with synthetic substance P and SPLI from rat skin. These results confirm the hypothesis that electrical stimulation results in release of substance P from nerve terminals in the skin, and therefore fulfils an important criterion of its role as a mediator of neurogenic inflammation.
D M
DM
White
R D
RD
Helme
D000818:Animals; D004195:Disease Models, Animal; D004558:Electric Stimulation; D007249:Inflammation / Q000378:metabolism*; D008297:Male; D009411:Nerve Endings / Q000378:metabolism; D010525:Peripheral Nerves / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000378:metabolism*
D013373:Substance P