Effect of Stimulation-Length Sequence on Shape of Length-Tension Diagram

¹ From the Departments of Physiology, University of North Carolina, Chapel Hill, North Carolina, and State University of Iowa, Iowa City, Iowa

Length-tension diagrams have been obtained from rat gastrocnemii stimulated under various stimulation-length sequences. The sequences were selected in an attempt to discover the origin of a secondary maximum on active and total length-tension curves, when these were derived by a commonly accepted technique. Two working hypotheses were advanced. The results indicate that several length-tension characteristics are dependent upon stimulation-length sequence, and that under the conditions examined the most important of these characteristics are extensibility and equilibrium length. As a consequence, neither working hypothesis appeared entirely satisfactory.