Biomaterial Database

Tachykinin-induced contractions in the circular muscle of guinea pig ileum. 1994

N Suzuki, and K Mizuno, and Y Gomi

Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kanazawa University, Japan.

Actions of substance P (SP, 10(-9) to 10(-6) M), neurokinin A (NKA, 10(-9) to 10(-6) M) and neurokinin B (NKB, 10(-10) to 10(-6) M) in the circular muscle of guinea pig ileum were investigated in segment and strip preparations, in which methacholine produced similar contractions. In the segment preparations, three tachykinins produced repeatedly occurring twitch-like contractions. Their efficacies were similar with the same maximal contractions, but their potencies were different (NKB > NKA = SP). Latency (38 sec) was observed before the initiation of contractions in response to NKA, but not to SP or NKB. Atropine (10(-6) M) and tetrodotoxin (3 x 10(-7) M) did not affect NKA-induced contractions, but inhibited SP- and NKB-induced contractions; the dose-response curves for SP and NKB were rightwardly shifted by atropine. The treatment with atropine brought out latency in the responses for NKB. In the strip preparations, SP did not substantially induce concentrations, but NKA and NKB produced twitch-like contractions after latent periods of 28 and 36 sec, respectively. The efficacy of NKA was similar to that in segment preparations, while that of NKB was much lower in strip preparations. Unlike in segment preparations, atropine did not inhibit contractions induced by the two tachykinins in strip preparations. These results suggest that tachykinins induce contractions through myogenic and neurogenic mechanisms, the latter of which may be inoperative in strip preparations.

UI	MeSH Term	Description	Entries
D006993	Hypnotics and Sedatives	Drugs used to induce drowsiness or sleep or to reduce psychological excitement or anxiety.	Hypnotic,Sedative,Sedative and Hypnotic,Sedatives,Hypnotic Effect,Hypnotic Effects,Hypnotics,Sedative Effect,Sedative Effects,Sedatives and Hypnotics,Effect, Hypnotic,Effect, Sedative,Effects, Hypnotic,Effects, Sedative,Hypnotic and Sedative
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
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D010456	Peptides, Cyclic	Peptides whose amino acid residues are linked together forming a circular chain. Some of them are ANTI-INFECTIVE AGENTS; some are biosynthesized non-ribosomally (PEPTIDE BIOSYNTHESIS, NON-RIBOSOMAL).	Circular Peptide,Cyclic Peptide,Cyclic Peptides,Cyclopeptide,Orbitide,Circular Peptides,Cyclopeptides,Orbitides,Peptide, Circular,Peptide, Cyclic,Peptides, Circular
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
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
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