Effect of substance P on rat gastrointestinal transit.
The in vivo effect of substance P and related peptide analogs on gastrointestinal transit in unanesthetized rats was studied. Fasted male rats were given intragastrically 0.5 ml of a powdered charcoal (BaSo4.H2O) meal and were concomitantly injected intraperitoneally with 8 micrograms/kg of substance P or a related peptide. In control rats, the percentage of small intestine traversed by the meal 15 min after feeding was 44.9 +/- 1.4 (N = 12). Substance P, [pGlu6]SP, [pGlu6, gPhe8, mGly9]SP and [pGlu5, N-MePhe8, N-MeGly9]SP significantly accelerated intestinal transit: 59.5 +/- 3.1% (N = 7); 66.0 +/- 3.8% (N = 14), 66.8 +/- 2.4% (N = 25), and 58.4 +/- 4.4% (N = 4), respectively. Concomitant injection of [pGlu6]SP and BOC-Phe-Phe-Gly-NHOH, an inhibitor of enzyme degradation at a dose of 800 micrograms/kg lowered by 10-fold the dose of [pGlu6]SP needed to induce the same degree of intestinal transit acceleration. These results indicate that in rats, substance P and related peptides accelerate gastrointestinal transit.
D000818:Animals; D005772:Gastrointestinal Transit / Q000187:drug effects*; D006898:Hydroxylamines / Q000494:pharmacology; D008297:Male; D009842:Oligopeptides / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D013373:Substance P / Q000031:analogs & derivatives* / Q000494:pharmacology*
D006898:Hydroxylamines; D009842:Oligopeptides; D010446:Peptide Fragments; D013373:Substance P; C026238:substance P (6-11), pGlu(6)-; C054754:tert-butyloxycarbonyl-phenylalanyl-phenylalanyl-glycine hydroxylamine; D011761:Pyrrolidonecarboxylic Acid