Distribution of substance P in the rat gastrointestinal tract--lack of effect of capsaicin pretreatment.
A new method for extraction of immunoreactive substance P (I-SP) from rat intestine including pulverization of tissue frozen in liquid nitrogen and extraction with acid acetone is described. Using this method, amounts of I-SP in the rat intestine were found to be higher than previously reported. The highest concentrations of I-SP were found in the small intestine. Capsaicin pretreatment of newborn or adult rats had no effect on intestinal I-SP concentrations indicating that intrinsic SP neurones are capsaicin-insensitive.
D000818:Animals; D000831:Animals, Newborn; D002211:Capsaicin / Q000494:pharmacology*; D002850:Chromatography, Gel; D004064:Digestive System / Q000187:drug effects / Q000378:metabolism*; D004347:Drug Interactions; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005260:Female; D007082:Ileum / Q000378:metabolism; D008297:Male; D051381:Rats; D013373:Substance P / Q000032:analysis / Q000378:metabolism*
D005231:Fatty Acids, Unsaturated; D013373:Substance P; D002211:Capsaicin