TY - JOUR
T1 - Changes in the gene expression of six subtypes of P2X receptors in rat dorsal root ganglion after spinal nerve ligation
AU - Kim, Changhoon
AU - Chung, Jin Mo
AU - Chung, Kyungsoon
N1 - Funding Information:
This work was supported by NIH Grants NS31680 and NS11255.
PY - 2003/2/6
Y1 - 2003/2/6
N2 - Increased purinergic sensitivity of injured sensory neurons suggests the possible involvement of purinoceptors for the generation of pain after nerve injury. To identify the purinoceptors that are involved, the changes in mRNA levels of 6 subtype purinoceptors were examined in the dorsal root ganglia (DRG) of the normal rat and after spinal nerve ligation, using RNase protection assay (RPA). In addition, the P2X2 containing neurons were examined in the L5 DRG, using an immunohistochemical method. The relative amounts of mRNAs for the six purinoceptor subtypes were in the order of P2X3≫P2X4>P2X6>P2X 5≃P2X2>P2X1 in the normal lumbar DRG. After nerve injury, the mRNA of P2X5 was increased, those of P2X3 and P2X6 were decreased, and those of P2X2 and P2X4 were unchanged. Immunohistochemical studies, however, showed 23% of the total DRG neurons are P2X2 positive in the normal L5 DRG, but that increased to 73% after nerve ligation. These data suggest that not only transcriptional but also posttranscriptional changes of multiple purinoceptors might be involved in the enhancement of purinergic sensitivity in injured sensory neurons.
AB - Increased purinergic sensitivity of injured sensory neurons suggests the possible involvement of purinoceptors for the generation of pain after nerve injury. To identify the purinoceptors that are involved, the changes in mRNA levels of 6 subtype purinoceptors were examined in the dorsal root ganglia (DRG) of the normal rat and after spinal nerve ligation, using RNase protection assay (RPA). In addition, the P2X2 containing neurons were examined in the L5 DRG, using an immunohistochemical method. The relative amounts of mRNAs for the six purinoceptor subtypes were in the order of P2X3≫P2X4>P2X6>P2X 5≃P2X2>P2X1 in the normal lumbar DRG. After nerve injury, the mRNA of P2X5 was increased, those of P2X3 and P2X6 were decreased, and those of P2X2 and P2X4 were unchanged. Immunohistochemical studies, however, showed 23% of the total DRG neurons are P2X2 positive in the normal L5 DRG, but that increased to 73% after nerve ligation. These data suggest that not only transcriptional but also posttranscriptional changes of multiple purinoceptors might be involved in the enhancement of purinergic sensitivity in injured sensory neurons.
KW - Dorsal root ganglia
KW - Mechanical allodynia
KW - Neuropathic pain
KW - P2X-immunoreactivity
KW - Purinoceptor mRNA
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U2 - 10.1016/s0304-3940(02)01302-2
DO - 10.1016/s0304-3940(02)01302-2
M3 - Article
C2 - 12527393
AN - SCOPUS:0037421490
SN - 0304-3940
VL - 337
SP - 81
EP - 84
JO - Neuroscience Letters
JF - Neuroscience Letters
IS - 2
ER -