This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.
In Reply.—The mechanism for excitation-contraction, as outlined in our article, is appropriate for cardiac and not smooth muscle. Drs Miller-Hance and Stull offer a clear description of the proposed mechanism for smooth-muscle contraction, which is an area, as they point out, still undergoing considerable investigation.