Effects of complete Freund's adjuvant on immunohistochemical distribution of IL-1beta and IL-1R I in neurons and glia cells of dorsal root ganglion.
OBJECTIVE
To investigate the effects of complete Freund adjuvant (CFA) on inflammatory hyperalgesia and morphological change of the coexistence of interleukin-1 beta (IL-1beta) and type I IL-1 receptor (IL-1RI) in neurons and glia cells of rat dorsal root ganglion (DRG).


METHODS
The pain-related parameters and the expression of IL-1RI and IL-1beta positive neurons and glia cells of DRG in normal saline (NS) and adjuvant-induced arthritic (AA) group were examined with pain behavior assessment methods and immunohistochemical assay, respectively.


RESULTS
Five hours, 1 d, and 2 d after intra-articular injection of 50 microL CFA, tactile hyperalgesia induced by CFA was observed in the foot flexion and extension scores of the ipsilateral hindpaw of AA group. Three days after injection, the distribution of IL-1RI/IL-1beta double-stained coexisted neurons and glia cells were observed in ipsilateral DRG of both groups. The number of IL-1beta positive neurons, IL-1RI positive neurons, IL-1beta/IL-1RI double-stained neurons, and IL-1RI positive glia cells in ipsilateral DRG of the AA group were higher than that of NS group (P<0.05 or P<0.01).


CONCLUSIONS
The coexistence of IL-1beta and IL-1RI in neurons and nonneuronal cells suggests an as yet unknown autocrine and/or paracrine function of IL-1beta in the DRG. The function was enhanced in articular arthritis induced by CFA and could play an important role in hyperalgesia under inflammatory conditions.
Li
Man
M
Department of Neurobiology, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China.
Shi
Jing
J
Tang
Jun-Rui
JR
Chen
Di
D
Ai
Bo
B
Chen
Jun
J
Wang
Li-Na
LN
Cao
Fu-Yuan
FY
Li
Ling-Li
LL
Lin
Chuan-You
CY
Guan
Xin-Min
XM
D000818:Animals; D001169:Arthritis, Experimental / Q000473:pathology; D005620:Freund's Adjuvant; D005727:Ganglia, Spinal / Q000473:pathology*; D006930:Hyperalgesia / Q000139:chemically induced / Q000473:pathology*; D007375:Interleukin-1 / Q000378:metabolism*; D008297:Male; D009457:Neuroglia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D017472:Receptors, Interleukin-1 / Q000378:metabolism*; D053573:Receptors, Interleukin-1 Type I
D007375:Interleukin-1; D017472:Receptors, Interleukin-1; D053573:Receptors, Interleukin-1 Type I; D005620:Freund's Adjuvant