¹ From the Department of Physiology, College of Physicians and Surgeons, Columbia University, New York 10032

Potassium-induced contractures were studied in single fibers from the semitendinosus muscle of Rana pipiens. Contractures elicited by solutions containing 60–117 mM potassium and 120 mM chloride were biphasic, consisting of a rapid initial contraction with a duration at 23°C of less than 1 sec followed by a slow response with a duration of many seconds. At 13°C, the initial response was greatly prolonged so that the two responses virtually fused into a single smooth contracture. Membrane potential in high potassium, high chloride solutions underwent a transient peak depolarization, probably as a result of time-dependent changes in membrane conductance during depolarization. It is proposed that this complex time course of depolarization gives rise to the biphasic contracture response.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents