Release of substance P-like immunoreactivity from the vascularly perfused rat stomach.
The release of gastric substance P-like immunoreactivity (SP-LI) has been studied in the vascularly perfused rat stomach. In the presence of 20 microM bacitracin and captopril, basal release of SP-LI was sustained throughout the experiments. Gastric SP-LI release was stimulated in a concentration-dependent manner by increasing the concentration of KCl in the perfusion medium. This stimulated release was reduced by the omission of Ca2+, indicating that a Ca2(+)-dependent mechanism was involved. Naloxone did not alter basal SP-LI secretion. [Met5]Enkephalin also had no significant effect on K(+)-stimulated secretion suggesting that enkephalinergic mechanisms are not involved. Gastric SP-LI release was also increased by capsaicin perfusion but this was not sustained. In conclusion, the present results provide the first evidence for the release of SP-LI into the rat stomach vasculature.
Department of Physiology, University of British Columbia, Vancouver, Canada.
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Kwok
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McIntosh
D000818:Animals; D001414:Bacitracin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004744:Enkephalin, Methionine / Q000494:pharmacology; D005753:Gastric Mucosa / Q000378:metabolism*; D066298:In Vitro Techniques; D009270:Naloxone / Q000494:pharmacology; D010477:Perfusion; D011188:Potassium / Q000494:pharmacology; D011863:Radioimmunoassay; D051381:Rats; D012039:Regional Blood Flow / Q000187:drug effects; D013270:Stomach / Q000098:blood supply / Q000187:drug effects; D013373:Substance P / Q000276:immunology / Q000378:metabolism*
D001414:Bacitracin; D013373:Substance P; D009270:Naloxone; D004744:Enkephalin, Methionine; D011188:Potassium; D002211:Capsaicin; D002118:Calcium