Mahmod, S. M. and Huddart, H. (1993) Calcium dependence of electrical and mechanical activity in rat ileum examined by the sucrose-gap technique. Comparative Biochemistry and Physiology Part C: Comparative Pharmacology, 105 (3). pp. 387-391. ISSN 0306-4492Full text not available from this repository.
1. Single sucrose gap recordings showed that spontaneous action potentials of rat ileal smooth muscle consisted of slow waves and superimposed spikes which generated rhythmic contractions. As external potassium was raised, the resting potential progressively depolarized. 2. Calcium-free salines inhibited spontaneous mechanical activity and inhibited the plateau phase of the action potential, but spontaneous spike depolarizations persisted. 3. Verapamil, nifedipine and diltiazem all inhibited spontaneous mechanical activity and the plateau phase of the action potential, while in addition diltiazem augmented spike amplitude. 4. Mn ions also inhibited mechanical activity and the action potential plateau, without affecting spike activity while the calcium ionophore A23187 enhanced both mechanical and electrical activity with a pronounced effect on spike amplitude. 5. These results are consistent with the view that the plateau phase of the ileal smooth muscle action potential is dependent upon an influx of extracellular calcium possibly through voltage dependent slow calcium channels.
|Journal or Publication Title:||Comparative Biochemistry and Physiology Part C: Comparative Pharmacology|
|Uncontrolled Keywords:||Ileum ; Action potential ; Smooth muscle ; Muscle contraction ; Ionic channel ; Calcium ; Rat ; Small intestine ; Digestive system ; Electrophysiology ; Rodentia ; Mammalia ; Vertebrata|
|Subjects:||G Geography. Anthropology. Recreation > GE Environmental Sciences|
|Deposited On:||21 Jan 2009 16:42|
|Last Modified:||07 Jan 2015 13:41|
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