Membrane Potentials in Longitudinal Smooth Muscle isolated from Guinea-pig Ileum

Abstract

THE activity of the smooth muscle in guinea-pig ileum has been investigated many times. The tissue preparation most often used for such investigations has been the isolated ileum. In a number of cases, however, experiments have been carried out, not with the whole ileum, but with the thin outer layer of longitudinal smooth muscle that can be easily separated from the ileum^1–3. This communication provides a brief description of membrane potentials which occur in this isolated muscle preparation. The work arose from an interest in correlating electrical activity with the transmembrane movements of potassium ion and the mechanical responses of the muscle that have been examined previously. It was desirable, therefore, to explore the feasibility of estimating changes in electrical activity in this preparation.