C. Tohda et al., Axonal transport of VR1 capsaicin receptor mRNA in primary afferents and its participation in inflammation-induced increase in capsaicin sensitivity, J NEUROCHEM, 76(6), 2001, pp. 1628-1635
Capsaicin receptors are expressed in primary sensory neurons and excited by
heat and protons. We examined the inflammation-induced changes of the leve
l of VR1 capsaicin receptor mRNA in sensory neurons and the sensitivity of
primary afferents to capsaicin. Carrageenan treatment induced axonal transp
ort of VR1 mRNA, but not that of preprotachykinin mRNA, from the dorsal roo
t ganglia to central and peripheral axon terminals. The sensitivity of cent
ral terminals to capsaicin, which was estimated by measuring the capsaicin-
evoked release of glutamate from the dorsal horn, was increased by peripher
al inflammation, and such an increase was suppressed by inhibiting the RNA
translation in the dorsal horn with cycloheximide and an intrathecal inject
ion of VR1 antisense oligonucleotides. Thus, peripheral inflammation induce
s the axonal transport of VR1 mRNA, which may be involved in the hypersensi
tivity of primary afferents to capsaicin and the production of inflammatory
hyperalgesia.