Neurokinin A and substance P vary independently in different regions of rat sensory neurons.
Neurokinin A (NKA) and substance P (SP) are often co-localized in small sensory neurons and have been suggested to subserve similar roles. We have now compared tissue levels of NKA and SP in rat cervical dorsal root ganglia with those in the central and peripheral terminations of the same neurons. We found that NKA content was less than that of SP in dorsal root neuron perikarya and in two peripheral tissues (superior cervical ganglion and ear skin) containing SP axon terminals from cervical spinal ganglia; in a third peripheral tissue, trachea, equal amounts of NKA and SP were present. By contrast, in the spinal cord containing the central terminals of these sensory neurons there was almost twice as much NKA as SP. Our results indicate that, although NKA and SP are co-localized in sensory neurons, their levels vary independently, suggesting distinct functional roles.
Bakhle
Y S
YS
Department of Applied Pharmacology, National Heart and Lung Institute, London, UK.
Bell
C
C
D000818:Animals; D004423:Ear / Q000294:innervation; D005727:Ganglia, Spinal / Q000166:cytology; D008297:Male; D015288:Neurokinin A / Q000032:analysis* / Q000276:immunology; D009475:Neurons, Afferent / Q000737:chemistry* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000737:chemistry; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000166:cytology; D013373:Substance P / Q000032:analysis* / Q000276:immunology; D017783:Superior Cervical Ganglion / Q000166:cytology; D014132:Trachea / Q000294:innervation
D013373:Substance P; D015288:Neurokinin A