Article date: 1992/6/17
PubMed ID: 1385165
Journal name: European journal of pharmacology (ISSN: 0014-2999)
The effects of an N-terminal fragment of substance P, substance P-(1-7) [SP-(1-7)], on the responses of dorsal horn nociceptive neurons to N-methyl-D-aspartate (NMDA) and (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) were tested by combined single-unit extracellular recordings/microiontophoresis. While SP-(1-7) had no effects when applied by itself, it was a potent and long-lasting modulator of both NMDA- and AMPA-mediated excitation of spinal dorsal horn nociceptive neurons. NMDA responses were transiently decreased (by an average of 36% of control at minimum) by SP-(1-7) followed by a more sustained increase (by 76% at maximum). In contrast, AMP responses were only increased by SP-(1-7) (by 81% at maximum). It is hypothesized that the actions of SP-(1-7) on excitatory amino acid (EAA) responses of dorsal horn nociceptive neurons reflect a novel mechanism by which SP and EAAs interact to modulate pain transmission.
Author List: Budai D, Wilcox G L, Larson A A
Publication Types: Journal Article; Research Support, U.S. Gov't, P.H.S.
Substances mentioned in the article: Peptide Fragments; Ibotenic Acid; Substance P; N-Methylaspartate; substance P (1-7); alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid;
Mesh terms: Animals; Drug Interactions; Ibotenic Acid/analogs & derivatives; Male; N-Methylaspartate/pharmacology; Neurons/drug effects; Nociceptors/drug effects; Peptide Fragments/pharmacology; Rats; Rats, Sprague-Dawley; Spinal Cord/drug effects; Substance P/pharmacology; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid;