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Updated: Jun 19, 2026

High-Throughput Contractile Measurements of Hydrogel-Embedded Intact Mouse Muscle Fibers Using an Optics-Based System
Published on: May 5, 2023
CONTRACTION IN GLYCERINATED MYOFIBRILS OF AN INSECT (ORTHOPTERA, ACRIDIDAE)
1Division of Entomology, Commonwealth Scientific and Industrial Research Organisation, Canberra, Australia.
Abstract:
The A substance of glycerol-treated myofibrils of the femoral muscles of the locust Gastrimargus musicus (Fabr.), removed by a salt solution of high ionic strength, has the properties of actomyosin. A phase contrast study of these fibrils, contracted by the addition of ATP, has revealed that the A bands of most myofibrils shorten during contraction. Changes in density within the A band lead to the formation of C(m) and C(z) bands while I bands are still present. The A band region between the contraction bands is of much lower density than it is in the uncontracted fibril. During contraction in some fibrils the I bands disappeared and the A bands remained unchanged in length until contraction bands appeared. These results have been interpreted in terms of coiling and stretching of the thick filaments of the sarcomere.
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