Dinitrofluorobenzene-induced rigor in ileal longitudinal smooth muscle of the guinea-pig.
1. The administration of 2,4-dinitrofluorobenzene (DFB) (0.1-1 mM) to the ileal longitudinal muscle produced contractions within seconds of its administration. 2. A component of the first 2 min duration of the phasic phase of 1 or 0.5 mM DFB contraction and the first phase of 0.35 or 0.1 mM DFB contraction was inhibited by Ca2+ antagonists, 1 x 10(-6) M D-600. 3. The DFB contraction resistant to D-600 began to develop when the tissue ATP concentration rapidly reduced. 4. The DFB contraction in ileum consists of two components; an initial fast contraction which is sensitive to Ca2+ antagonists, and a late contraction referred to as a rigor which is resistant to it.
Department of Veterinary Pharmacology, Faculty of Agriculture, Yamaguchi University, Japan.
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D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004139:Dinitrofluorobenzene / Q000633:toxicity*; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects / Q000378:metabolism; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000378:metabolism
D000255:Adenosine Triphosphate; D004139:Dinitrofluorobenzene