Expression of neurokinin-1 receptors on cultured dorsal root ganglion neurons from the adult rat.
The expression of neurokinin-1 receptors in isolated dorsal root ganglion neurons of adult rats was investigated using substance P covalently bound to a 1.4-nm gold particle. Binding of substance P-gold was determined in neurons after 0.8, 1.8 or 3.8 days under culture conditions. Substance P-gold binding sites were identified in 9.5 +/- 1.8% of the neurons that were cultured for 0.8 days. The proportion of neurons with substance P-gold binding sites increased to 21.5 +/- 3.6% after 1.8 days in culture and returned to the initial values (9.2 +/- 2.1%) after 3.8 days in culture. Binding of substance P-gold was suppressed by co-administration of [Sar9, Met(O2)11] substance P, a specific agonist at the neurokinin-1 receptor, but not by co-administration of [beta-Ala8] Neurokinin A (4-10), an agonist at the neurokinin-2 receptor, and senktide, an agonist at the neurokinin-3 receptor. This indicates that substance P-gold was bound specifically to neurokinin-1 receptors. Double-labelling with RT97, an antibody that selectively labels somata of A-fibres revealed that substance P binding sites were present in small neurons with myelinated and unmyelinated axons. These data show that a proportion of dorsal root ganglion neurons of adult rat in culture exhibit neurokinin-1 receptors. A transient increase in the proportion of neurons expressing neurokinin-1 receptors after 1.8 days in culture suggests that the expression of neurokinin-1 receptors is subjected to regulation.
Segond von Banchet
G
G
Physiologisches Institut der Universität Würzburg, Germany.
Petersen
M
M
Schaible
H G
HG
D000818:Animals; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D015288:Neurokinin A / Q000031:analogs & derivatives / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018040:Receptors, Neurokinin-1 / Q000096:biosynthesis* / Q000378:metabolism; D013373:Substance P / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D013997:Time Factors
D010446:Peptide Fragments; D018040:Receptors, Neurokinin-1; C054724:senktide; C064218:neurokinin A (4-10), beta-Ala(8)-; D013373:Substance P; D015288:Neurokinin A