title: Inhibition of 5-hydroxytryptamine contraction of guinea-pig smooth muscle treated with black widow spider venom.
abstract: Black widow spider venom (BWSV) elicited a prolonged tonic contraction of guinea-pig ileum which abolished the nicotine-induced contraction; however, the subsequent acetylcholine stimulation was found to be unchanged. These findings indicate a depletion of nerve terminal transmitters caused by BWSV without a disruption of the muscle contractile mechanism. Following the BWSV-induced contraction, the stimulation to 5-hydroxytryptamine (5-HT) was found to be abolished. This abolishment indicates a mediation of 5-HT-induced smooth muscle contraction in the nerve rather than the muscle.
mesh_terms: D000818:Animals; D001180:Arthropod Venoms / Q000494:pharmacology*; D001740:Black Widow Spider / Q000502:physiology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D012702:Serotonin Antagonists; D013111:Spider Venoms / Q000494:pharmacology*; D013112:Spiders / Q000502:physiology*
chemical_list: D001180:Arthropod Venoms; D012702:Serotonin Antagonists; D013111:Spider Venoms