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Updated: May 27, 2026

Procedures for Rat in situ Skeletal Muscle Contractile Properties
Published on: October 15, 2011
Pressure-induced pH and length changes in muscle
J J Macfarlane1, I J McKenzie, R H Turner
1CSIRO Division of Food Research, Meat Research Laboratory, Cannon Hill, Queensland, 4170, Australia.
Abstract:
The response to increase in pressure of pre- and post-rigor muscle strips supporting a load has been investigated by measuring length changes with application of pressure up to 150 MPa in a windowed pressure vessel. The response of the pre-rigor strips depended on temperature; at 30°C the strips contracted, then, after some minutes, lengthened, presumably because of a breakdown of myofibrillar integrity. At 0°C the cold-shortened muscle lengthened but if pressure was released the strips shortened again. Loaded post-rigor muscle strips lengthened with application of pressure. It is suggested that the conditions that prevail in pre-rigor muscle are not as favourable for disaggregation of the myofilaments as those in post-rigor muscle. Measuresurement of pH changes in pre-rigor pressure-treated muscle showed these were accelerated at 30°C, but completely inhibited by treatment at 0°C for 3 or 24h.
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