The release of substance P from cultured dorsal root ganglion neurons requires the non-neuronal cells around these neurons.
Substance P is known to be released from dorsal root ganglion (DRG) neurons, but the possible involvement of non-neuronal cells in the process of substance P release is not known. During the culture period, the number of surviving DRG neurons, the total substance P content from the culture medium and DRG cells, and the total protein of DRG cells were monitored. Both the number of surviving neurons and the total substance P content decreased in a time-dependent manner, whereas the total protein synthesis was increased. The localization of substance P in small-to-medium-sized neurons was further confirmed by immunocytochemistry. Finally, the substance P release levels from the neuronal and non-neuronal enrichments were investigated by radioimmunoassay. Both partially purified DRG neurons and non-neuronal cells exhibited a weaker substance P release response to capsaicin or KCl, relative to unpurified DRG cells. The total substance P content from the partially purified DRG neurons was almost the same as that from the unpurified DRG cells, but much more than that from the partially purified DRG non-neuronal cells. These findings suggest that substance P is released from DRG neurons, and this process should require the coexistence of neurons and non-neuronal cells.
Tang
He-Bin
HB
Department of Pharmacology, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan.
Li
Yu-Sang
YS
Nakata
Yoshihiro
Y
D000818:Animals; D002211:Capsaicin / Q000494:pharmacology; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D007150:Immunohistochemistry; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013373:Substance P / Q000032:analysis / Q000378:metabolism*
D013373:Substance P; D011189:Potassium Chloride; D002211:Capsaicin