Induction of nerve growth factor mRNA in a rat dorsal root ganglion after application of a tourniquet.
We investigated the mRNA levels of neurotrophins and neurotrophin receptors in a rat dorsal root ganglion (DRG), after tourniquet application to a hind limb, to identify the nerve-protective molecules that are induced immediately after peripheral nerve crush and play a part in the process leading to secondary events. No significant expression of nerve growth factor (NGF) mRNA or protein was observed in the control or contralateral DRG. NGF mRNA expression started within 2 h and NGF protein expression was observed in Schwann cells at 4 h after application of the tourniquet, due to termination of the neurotrophin supply from peripheral nerves. The levels of neurotrophin 3 mRNA were significantly increased in the DRGs on both sides at 1 and 2 h after tourniquet application, but no significant changes in brain-derived neurotrophic factor and neurotrophin 4/5 expression levels were observed in either the contralateral or ipsilateral DRG. The expression levels of neurotrophin receptors in the DRGs on both the contralateral and ipsilateral sides had decreased at 1 to 2 h after application of the tourniquet and had returned to the control levels at 4 h after tourniquet application.
Abe
Sumiko
S
Department of Legal Medicine, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima 960-1295, Japan. sumiko@fmu.ac.jp
Mizusawa
Ikubumi
I
Kanno
Katsuyuki
K
Yabashi
Atsuko
A
Suto
Miwako
M
Kuraya
Mikio
M
Honda
Takashi
T
Hiraiwa
Kouichi
K
D000818:Animals; D017931:DNA Primers; D007839:Functional Laterality; D005727:Ganglia, Spinal / Q000378:metabolism*; D006614:Hindlimb / Q000098:blood supply; D007150:Immunohistochemistry; D008297:Male; D009409:Nerve Crush; D020932:Nerve Growth Factor / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D017475:Receptors, Nerve Growth Factor / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014111:Tourniquets
D017931:DNA Primers; D012333:RNA, Messenger; D017475:Receptors, Nerve Growth Factor; D020932:Nerve Growth Factor