title: Effect of electrical field stimulation on muscle strips from chicken crop.
abstract: The effect of electrical field stimulation (EFS) on smooth muscle strips from the chicken crop was investigated. The EFS (5 Hz, 2 ms, 400 mA; 10 Hz, 2 ms, 400 mA; 5 Hz, 2 ms, 500 mA; 10 Hz, 2 ms, 500 mA) produced contractions in all preparations. Atropine (10(-5) mol l-1) diminished muscle contraction in response to EFS. Tetrodotoxin (5 X 10(-6) mol l-1) fully suppressed the contractile responses to EFS. A serotonin antagonist (methysergide, 10(-4) mol l-1) did not alter contractions elicited by EFS. Propranolol (10(-5) mol l-1) led to an increase of contractions induced by EFS. Noradrenaline (10(-6)-10(-4) mol l-1) reduced acetylcholine-induced (1.1 X 10(-6) mol l-1) contraction of the crop smooth muscle strips. Propranolol (10(-5) mol l-1) abolished noradrenaline-induced relaxation almost fully. Tetrodotoxin (5 X 10(-6) mol l-1) did not change the relaxing effect of noradrenaline. These results suggested that the responses of crop smooth muscle to EFS involve excitatory cholinergic and non-cholinergic (probably peptidergic) as well as inhibitory adrenergic nerves.
authors.affiliation: Institut für Veterinär Physiologie, Universität Zürich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Denac
authors.forename: G
authors.initials: G
authors.lastname: Kümin
authors.forename: E
authors.initials: E
authors.lastname: Scharrer
mesh_terms: D000818:Animals; D001285:Atropine; D002645:Chickens / Q000502:physiology*; D003426:Crop, Avian / Q000294:innervation*; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D008784:Methysergide; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D009130:Muscle, Smooth / Q000187:drug effects / Q000294:innervation*; D009638:Norepinephrine; D011433:Propranolol; D009435:Synaptic Transmission / Q000187:drug effects; D013779:Tetrodotoxin
chemical_list: D013779:Tetrodotoxin; D001285:Atropine; D011433:Propranolol; D009638:Norepinephrine; D008784:Methysergide