Substance P causes a chloride-dependent short-circuit current response in rabbit colonic mucosa in vitro

Scand J Gastroenterol. 1999 Dec;34(12):1203-11. doi: 10.1080/003655299750024715.


Background: The neuropeptide substance P (SP) induces secretion in animals. The effect of SP on rabbit colon is not known. We therefore investigated the effect of SP on rabbit colonic mucosa mounted in Ussing chambers.

Methods: Colonic mucosae were incubated with SP in Cl -containing or Cl -free buffer. Drugs for pharmacologic characterization of SP-induced electrophysiologic changes were applied to the serosal bath 30 min before SP administration.

Results: Serosal, but not luminal, administration of SP (10(-8)-10(-6) M) induced a rapid, transient, bumetanide-sensitive, dose- and chloride-dependent short-circuit current (Isc) increase (P < 0.001), which was inhibited by 85%, 80%, 82%, 90%, and 70% after serosal preincubation with the neurokinin-1 (NK-1) receptor antagonist CP-96,345, the neuronal blocker tetrodotoxin (10(-6)M), the mast cell stabilizer lodoxamide (10(-6) M), the H1-receptor antagonist pyrilamine (10(-6) M), or the prostaglandin synthesis inhibitor indomethacin (10(-6) M), respectively (P < 0.001).

Conclusions: SP stimulates a chloride-dependent Isc increase in the rabbit colon which is mediated by nerves and mast cells and the mast cell product histamine.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Chloride Channels / antagonists & inhibitors
  • Chlorides / metabolism
  • Colon / drug effects
  • Colon / physiology
  • Electrophysiology
  • In Vitro Techniques
  • Intestinal Mucosa / drug effects*
  • Intestinal Mucosa / physiology
  • Male
  • Mast Cells
  • Neurokinin-1 Receptor Antagonists
  • Prostaglandins / physiology
  • Rabbits
  • Substance P / pharmacology*


  • Chloride Channels
  • Chlorides
  • Neurokinin-1 Receptor Antagonists
  • Prostaglandins
  • Substance P