Effects of three mammalian tachykinins on single enteric neurons.
The effects of substance P (SP), substance K (SK) and neuromedin K (NMK) were compared on single neurons of the guinea pig myenteric plexus. The tachykinins depolarized all myenteric neurons with a rank order of potency SP greater than SK greater than NMK. In approximately 80% of neurons studies the depolarization was associated with an increase in membrane resistance: in 20% membrane resistance decreased. The depolarizations were not affected by tetrodotoxin (TTX) (300 nM), hyoscine (1 microM) or by [D-Arg1, D-Pro2, D-Trp7,9, Leu11]SP (1 microM). These results provide no evidence for more than one type of tachykinin receptor on myenteric neurons.
D000818:Animals; D004594:Electrophysiology; D006168:Guinea Pigs; D007421:Intestine, Small / Q000294:innervation*; D008297:Male; D009197:Myenteric Plexus / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D015288:Neurokinin A; D015287:Neurokinin B; D009474:Neurons / Q000145:classification / Q000187:drug effects* / Q000502:physiology; D009479:Neuropeptides / Q000494:pharmacology*; D013373:Substance P / Q000494:pharmacology*
D009479:Neuropeptides; D013373:Substance P; D015288:Neurokinin A; D015287:Neurokinin B