Substance P in renal afferent perikarya identified by retrograde transport of fluorescent dye.

Substance P immunoreactivity in the afferent pathways to the kidney of the cat was investigated by using combined retrograde fluorescent dye labeling and indirect immunofluorescent techniques. Substance P was identified in 24% of dye-labeled renal afferent neurons in the dorsal root ganglia from L1 to L3. By comparison, 29% of all cells in the lumbar ganglia were substance P-positive. These data indicate that substance P may be involved in the transmission of afferent input from the kidney to the central nervous system.