[Substance P and/or calcitonin gene-related peptide immunoreactive neurons in dorsal root ganglia possibly involved in the transmission of nociception in rat penile frenulum].
OBJECTIVE
To study the relationship between substance P (SP) and/or calcitonin gene-related peptide (CGRP) immunoreactive neurons in dorsal root ganglia (DRG) and the transmission of nociception in the penile frenulum of rats.


METHODS
The fluoro-gold (FG) retrograde tracing method was used to trace the origin of nerve terminals in the penile frenulum of rats. And SP and/or CGRP immunofluorescence labeling was employed to detect the distribution of SP and/or CGRP immunoreactive neurons in DRG.


RESULTS
FG retrograde tracing showed that the FG retrolabeled neurons were localized in L6-DRG and S1-DRG. SP and/or CGRP immunofluorescence labeling indicated that a large number of DRG neurons were SP- and CGRP-immunoreactive, different in size, bright red and bright green respectively in color, and arranged in rows or spots among nerve bundles. All the FG/SP and FG/CGRP double-labeled neurons were medium or small-sized. One third of the FG-labeled neurons were SP-immunoreactive, and a half of them CGRP-immunoreactive in L6-DRG and S1-DRG respectively. The FG/SP/CGRP-labeled neurons accounted for one fifth of the FG retro labeled neurons.


CONCLUSIONS
SP- and CGRP-immunoreactive neurons in L6-DRG and SI-DRG of rats may be involved in the transmission of nociception in rat penile frenulum.
Wu
Zhong-Min
ZM
Department of Anatomy, Medical College of Taizhou University, Taizhou, Zhejiang 318000, China. wzmbest@163.com
Ni
Jing-Jing
JJ
Ling
Shu-Cai
SC
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis*; D005727:Ganglia, Spinal / Q000737:chemistry / Q000166:cytology; D008297:Male; D008856:Microscopy, Fluorescence; D009474:Neurons / Q000737:chemistry* / Q000502:physiology; D009475:Neurons, Afferent / Q000737:chemistry / Q000502:physiology; D010413:Penis / Q000294:innervation*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013373:Substance P / Q000032:analysis*
D013373:Substance P; D015740:Calcitonin Gene-Related Peptide