Depletion of primary afferent substance P by capsaicin and dihydrocapsaicin without altered thermal sensitivity in rats.
Systemic administration of capsaicin and dihydrocapsaicin to adult rats of two different strains and of capsaicin to neonatal rats, depleted substance P levels in dorsal roots plus ganglia and in dorsal spinal cord. In no case was this depletion accompanied by substantially altered tail-flick latencies. The results are not consistent with a role of the neuropeptide in nociceptive thermal sensitivity in the rat.
D000818:Animals; D000831:Animals, Newborn; D002211:Capsaicin / Q000031:analogs & derivatives / Q000494:pharmacology*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005260:Female; D005727:Ganglia, Spinal / Q000187:drug effects; D008297:Male; D009068:Movement; D009475:Neurons, Afferent / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time; D013116:Spinal Cord / Q000187:drug effects; D013126:Spinal Nerve Roots / Q000187:drug effects; D013373:Substance P / Q000502:physiology*; D013623:Tail / Q000502:physiology; D013697:Thermosensing / Q000502:physiology*
D005231:Fatty Acids, Unsaturated; D013373:Substance P; D002211:Capsaicin; C012906:dihydrocapsaicin