Evidence that the contractile response of the guinea-pig ileum to capsaicin is due to substance P release. 1982

L A Chahl

The mechanism of action of capsaicin on the guinea-pig isolated ileum was studied. Capsaicin (1.5 x 10(-6) mol 1(-1) produced a large contractile response of the ileum which exhibited marked tachyphylaxis. The response was reduced by treatment of preparations with atropine, 5 x 10(-6) mol 1(-1), and by substance P-autodesensitization, and was abolished by a combination of these treatments. It was concluded that capsaicin released both substance P and acetylcholine from the guinea-pig ileum. Evidence for a cholinergic component in the action of high concentrations of substance P was also obtained and therefore it is proposed that capsaicin releases substance P from neurones in the ileum, and the released substance P in turn stimulates cholinergic neurones to release acetylcholine, as well as producing direct muscle contraction.

UI MeSH Term Description Entries
D007082 Ileum The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.
D008297 Male Males
D009119 Muscle Contraction A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments. Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D010830 Physostigmine A cholinesterase inhibitor that is rapidly absorbed through membranes. It can be applied topically to the conjunctiva. It also can cross the blood-brain barrier and is used when central nervous system effects are desired, as in the treatment of severe anticholinergic toxicity. Eserine
D002211 Capsaicin An alkylamide found in CAPSICUM that acts at TRPV CATION CHANNELS. 8-Methyl-N-Vanillyl-6-Nonenamide,Antiphlogistine Rub A-535 Capsaicin,Axsain,Capsaicine,Capsicum Farmaya,Capsidol,Capsin,Capzasin,Gelcen,Katrum,NGX-4010,Zacin,Zostrix,8 Methyl N Vanillyl 6 Nonenamide,NGX 4010,NGX4010
D005231 Fatty Acids, Unsaturated FATTY ACIDS in which the carbon chain contains one or more double or triple carbon-carbon bonds. Fatty Acids, Polyunsaturated,Polyunsaturated Fatty Acid,Unsaturated Fatty Acid,Polyunsaturated Fatty Acids,Acid, Polyunsaturated Fatty,Acid, Unsaturated Fatty,Acids, Polyunsaturated Fatty,Acids, Unsaturated Fatty,Fatty Acid, Polyunsaturated,Fatty Acid, Unsaturated,Unsaturated Fatty Acids
D005260 Female Females
D006168 Guinea Pigs A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research. Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000109 Acetylcholine A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system. 2-(Acetyloxy)-N,N,N-trimethylethanaminium,Acetilcolina Cusi,Acetylcholine Bromide,Acetylcholine Chloride,Acetylcholine Fluoride,Acetylcholine Hydroxide,Acetylcholine Iodide,Acetylcholine L-Tartrate,Acetylcholine Perchlorate,Acetylcholine Picrate,Acetylcholine Picrate (1:1),Acetylcholine Sulfate (1:1),Bromoacetylcholine,Chloroacetylcholine,Miochol,Acetylcholine L Tartrate,Bromide, Acetylcholine,Cusi, Acetilcolina,Fluoride, Acetylcholine,Hydroxide, Acetylcholine,Iodide, Acetylcholine,L-Tartrate, Acetylcholine,Perchlorate, Acetylcholine
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia

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L A Chahl
May 1979, Naunyn-Schmiedeberg's archives of pharmacology,
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