Development of a Model System Using Glycerinated Muscle for the Study of Physical Properties

A model system which duplicates in some of its properties the chemical and physical states of non-glycerinated muscle in its various postmortem states, has been developed using glycerinated muscle at different states of contraction. The state of the muscle was related to sarcomere length, extractable actomyosin, and binding of 1-fluoro-2, 4-dinitrobezene (FDNB) to myofibrillar proteins. It was established that FDNB binding was a more accurate measure of actomyosin formation in situ than was actomyosin extractability. FDNB binding was presumably related to thin and thick filament overlap, even after the Z disc was removed, whereas extraction of actomyosin was not. Results of extensibility with the glycerinated muscle could be predicted based on the model and matched that found with non-glycerinated muscle as described in the literature. The model system offers the following advantages over non-glycerinated muscle: stability, convenience, maintenance of a “pre-rigor” condition indefinitely, and a “pre-rigor” muscle that is not contractile.