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.
Department of Nephrology, Department of Rheumatology, Shandong University Qilu Hospital, Jinan, China.
Xiang-Dong
XD
Yang
Zhen
Z
Liu
Hua-Xiang
HX
Liu
Li-Hong
LH
Wang
Chun-Hong
CH
Ma
Zhen-Zhong
ZZ
Li
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