Afferent fibres from the guinea-pig ureter: size and peptide content of the dorsal root ganglion cells of origin.
A study was undertaken to determine the segmental organization of the dorsal root ganglion cells which give rise to ureteric primary afferent fibres in the guinea-pig. The size-distribution and peptide content of these dorsal root ganglion cells were examined and compared with a sample of all dorsal root ganglion cells from the same ganglia. Afferent fibres to the guinea-pig ureter were found to arise mainly from dorsal root ganglia L2-L3 and S1-S2. A large contralateral component of the afferent innervation of the ureter was found when either the right or the left ureter was injected with tracer. This amounted to approximately 40% of the total labelled cells. The cross-sectional areas of the dorsal root ganglion cells of ureteric afferents were found to be at the smaller end of the size-range for the whole ganglion. Most (90%) of the cells innervating the ureter were immunoreactive for one of the peptides studies, substance P or calcitonin gene-related peptide, and a large proportion (65%) were immunoreactive for both. This was very different for the ganglia as a whole, where only about 50% of the cells were immunoreactive for either of the peptides and only 14% were immunoreactive for both peptides. These results show a bilateral afferent innervation of the ureter by nerve fibres which, in the vast majority, contain substance P and/or calcitonin gene-related peptide.
Semenenko
F M
FM
Department of Physiology, School of Medical Sciences, University of Bristol, U.K.
Cervero
F
F
D000818:Animals; D004594:Electrophysiology; D005455:Fluorescent Antibody Technique; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D006168:Guinea Pigs; D008297:Male; D008856:Microscopy, Fluorescence; D009475:Neurons, Afferent / Q000378:metabolism / Q000502:physiology*; D009479:Neuropeptides / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism; D014513:Ureter / Q000294:innervation*
D009479:Neuropeptides; D013373:Substance P