title: Influence of electro-acupuncture on the release of substance P and the potential evoked by tooth pulp stimulation in the trigeminal nucleus caudalis of the rabbit.
abstract: The effects of electro-acupuncture (EAP) on the release of substance P (SP) and the responses evoked by tooth pulp stimulation (ST) in superficial layers of the trigeminal nucleus caudalis (Vc-I,II) were studied in rabbits. ST evoked increase in release of immunoreactive SP (iSP). This increase was inhibited by EAP in 9 of 13 animals. The potentials evoked by ST were composed of two main components with latency times of ca 4.3 msec and ca. 9.4 msec. The latter component, reflecting the excitation of A delta fibers, was significantly inhibited by CP-96,345 (3 mg/kg, i.v.), an SP antagonist. EAP also inhibited the latter component in 8 of 11 animals. These results suggest that one of the mechanisms of analgesia induced by EAP is inhibition of stimulus-evoked SP release in the Vc-I,II.
authors.affiliation: Department of Pharmacology, Faculty of Dentistry, Osaka University, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Yonehara
authors.forename: T
authors.initials: T
authors.lastname: Sawada
authors.forename: H
authors.initials: H
authors.lastname: Matsuura
authors.forename: R
authors.initials: R
authors.lastname: Inoki
mesh_terms: D000818:Animals; D003782:Dental Pulp / Q000502:physiology*; D004558:Electric Stimulation; D015671:Electroacupuncture; D005071:Evoked Potentials; D008297:Male; D011817:Rabbits; D011930:Reaction Time; D013373:Substance P / Q000378:metabolism*; D014275:Trigeminal Caudal Nucleus / Q000378:metabolism / Q000502:physiology*
chemical_list: D013373:Substance P