Regulatory effect of nerve growth factor on release of substance P in cultured dorsal root ganglion neurons of rat.
OBJECTIVE
To investigate the regulatory effects of nerve growth factor (NGF) on basal and capsaicin-induced release of neuropeptide substance P (SP) in primary cultured embryonic rat dorsal root ganglion (DRG) neurons.


METHODS
DRGs were dissected from 15-day-old embryonic Wistar rats. DRG neurons were dissociated and cultured, and then exposed to different concentrations of NGF (10 ng/mL, 30 ng/mL, or 100 ng/mL) for 72 h. The neurons cultured in media without NGF served as control. RT-PCR were used for detecting the mRNAs of SP and vanilloid receptor 1 (VR1) in the DRG neurons. The SP basal and capsaicin (100 nmol/L)-induced release in the culture were measured by radioimmunoassay (RIA).


RESULTS
SP mRNA and VR1 mRNA expression increased in primary cultured DRG neurons in a dose-dependent manner of NGF. Both basal release and capsaicin-evoked release of SP increased in NGF-treated DRG neurons compared with in control group. The capsaicin-evoked release of SP also increased in a dose-dependent manner of NGF.


CONCLUSIONS
NGF may promote both basal release and capsaicin-evoked release of SP. NGF might increase the sensitivity of nociceptors by increasing the SP mRNA or VR1 mRNA.
Yang
Xiang-Dong
XD
Department of Nephrology, Department of Rheumatology, Shandong University Qilu Hospital, Jinan, China.
Liu
Zhen
Z
Liu
Hua-Xiang
HX
Wang
Li-Hong
LH
Ma
Chun-Hong
CH
Li
Zhen-Zhong
ZZ
D018712:Analgesics, Non-Narcotic / Q000494:pharmacology; D000818:Animals; D002211:Capsaicin / Q000494:pharmacology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian; D005727:Ganglia, Spinal / Q000166:cytology*; D005786:Gene Expression Regulation / Q000187:drug effects; D020932:Nerve Growth Factor / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects*; D012333:RNA, Messenger / Q000378:metabolism; D011863:Radioimmunoassay / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D013373:Substance P / Q000235:genetics / Q000378:metabolism*
D018712:Analgesics, Non-Narcotic; D012333:RNA, Messenger; D013373:Substance P; D020932:Nerve Growth Factor; D002211:Capsaicin