The emetic and anti-emetic effects of the capsaicin analogue resiniferatoxin in Suncus murinus, the house musk shrew.

摘要: In Suncus murinus the ultrapotent capsaicin analogue resiniferatoxin (RTX) induced an emetic response in dose range 1–1000 μg kg−1, s.c. The latency was inversely related to and ranged from 41.2±4.4 min. (1 μg kg−1, s.c.) 2.7±0.6 min. (1000 μg kg−1, s.c.). The RTX (10 or 100 μg kg−1, blocked markedly reduced by pre-treatment with (100 μg kg−1, s.c.), 8-OH-DPAT morphine (2 mg kg−1, neonatal (100 mg kg−1, NK1 receptor antagonist CP-99,994 (10–20 mg kg−1, but not 5-HT3 tropisetron (200 μg kg−1, s.c.). RTX c-fos-like immunoreactivity area postrema parts of nucleus tractus solitarius. This pattern is consistent proposal that effect mediated via one both these structures involvement substance P discussed. RTX (10 and had broad-spectrum antiemetic effects as indicated its ability block reduce motion (1 Hz, 4 cm lateral, 10 min.), cisplatin (20 mg kg−1, i.p.), intragastric copper sulphate (40 mg kg−1, p.o.), nicotine (10 mg kg−1, itself. It proposed site anti-emetic solitarius mechanisms involving modulation release are discussed. The general utility for investigations vanilloid receptors reviewed light exquisite sensitivity reflex this species resiniferatoxin. British Journal Pharmacology (2000) 130, 1247–1254; doi:10.1038/sj.bjp.0703428