Pharmacological characteristics of tachykinin receptors mediating acetylcholine release from neonatal rat spinal cord.
The pharmacological profiles of tachykinin receptors mediating the release of acetylcholine were examined in the isolated spinal cord of the neonatal rat. The acetylcholine release evoked by neurokinin A or acetyl-[Arg6,Pro9]substance P-(6-11) was depressed by the tachykinin antagonists, spantide and GR71251 at 10 microM, whereas the release evoked by substance P (0.3 microM) or neurokinin B (0.3 microM) was not affected by these tachykinin antagonists. Polymerase chain reaction amplification of rat spinal cord cDNA and sequence analysis revealed the presence of a substantial amount of fragments having sequences identical to that of the NK1 or NK3 receptor, but only a few having a sequence identical to that of the NK2 receptor. These results suggest that in the neonatal rat spinal cord a novel subtype of tachykinin receptor similar but not identical to the classical NK1 receptor is involved in tachykinin-evoked acetylcholine release.
Suzuki
H
H
Department of Pharmacology, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
Yoshioka
K
K
Maehara
T
T
Hagan
R M
RM
Nakanishi
S
S
Otsuka
M
M
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D001483:Base Sequence; D018076:DNA, Complementary / Q000032:analysis; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000187:drug effects; D009467:Neuromuscular Depolarizing Agents / Q000494:pharmacology; D010957:Plasmids; D016133:Polymerase Chain Reaction; D051381:Rats; D017208:Rats, Wistar; D018040:Receptors, Neurokinin-1 / Q000187:drug effects; D018039:Receptors, Tachykinin / Q000037:antagonists & inhibitors / Q000187:drug effects* / Q000378:metabolism; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*; D015320:Tachykinins / Q000037:antagonists & inhibitors / Q000494:pharmacology
D018076:DNA, Complementary; D009467:Neuromuscular Depolarizing Agents; D018040:Receptors, Neurokinin-1; D018039:Receptors, Tachykinin; D015320:Tachykinins; D000109:Acetylcholine