[Effect of Fos expression induced by spinal nitric oxide on the nociception of formalin in rats].
OBJECTIVE
To assess the effect of s.c. injected formalin and clarify the possible mechanism of nociception in SD rats.


METHODS
Sixty-four healthy male rats were randomly distributed into the control groups (group NS, group formalin) and test groups (group LaF, group LnF) with correponding numbers. Group NS served as normal control. Group formalin was treated with 5% formalin 100 microliters, s.c. Groups LaF and LnF were treated respectively with L-Arg 4.7 mumol ith and L-NAME 370 nmol ith before receiving 5% formalin 100 microliters, s.c. like group formalin. 1/2 h and 0-1 h after formalin treatment, spinal cord segments were removed for expression of NOS, and behavior responses were observed.


RESULTS
The flinching and licking time of group formalin was longer than that of group NS, and NOS expression of group formalin was stronger than that of group NS. Pretreatment with L-Arg potentiated formalin-induced response, but pretreatment with L-NAME reduced the response.


CONCLUSIONS
Spinal nitric oxide release might be one of the nociception mechanisms in the formalin test.
Lin
Xuemei
X
Department of Anesthesiology, West China Second Hospital, Sichuan University, Chengdu 610041, China.
Wang
Quanyun
Q
Zhu
Lin
L
Yang
Bangxiang
B
Liu
Bin
B
D000818:Animals; D001522:Behavior, Animal; D005557:Formaldehyde; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009619:Nociceptors / Q000503:physiopathology*; D010146:Pain / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis* / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism*
D016760:Proto-Oncogene Proteins c-fos; D005557:Formaldehyde; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase