초록
Dorsal root ganglion(DRG) cells are primary sensory neurons which contain some biologically active neuropeptides which play a role as neurotransmitters or neuromodulators. This study was performed to observe normal distribution of calcitonin gene-related peptide (CGRP) and substance P (SP) immunoreactive cells and colocalization of CGRP and SP in a single DRG cell of the lumbar DRGs($L_1{\sim}L_6$) in the Wistar Kyoto(WKY) rat by immunohistochemistry. About 55.8% of DRG cells contained CGRP-immunoreactivity, while about 12.7% of DRG cells showed SP-immunoreactivity. There was no significant difference in percentage of each neuropeptied-immunoreactive cells between each neuropeptide-immunoreactive cells between each levels of DRGs ($L_1{\sim}L_6$) (p>0.01). In size distribution, CGRP-immunoreactive cells were identified below $1,500{\mu}m^2$; SP-immunoreactive cells below $600{\mu}m^2$. In serial sections, about 86.7% of the SP immunoreactive cells contained CGRP immunoreactivity.