Auto-oscillations in Extracted Muscle Fibre Systems

Abstract

IN the course of work on relaxing factors¹, Goodall and A. G. Szent-Györgyi¹ observed that with fibres showing less than maximal activity for the creatine phosphate–adenosine triphosphate relaxing system, an auto-oscillation of tension developed if the creatine phosphate was increased to 30–100 mM. These oscillations (Fig. 1) were observed on several occasions under the above conditions. They are independent of a pH. change from 6.8 to 5.9 which produces a 50 per cent fall of tension, as compared to 90 per cent for ‘active’ fibres. However, it is not certain that this ‘deactivation’ is an essential part of the extraction procedure; afterwards I found that 40 per cent ethylene glycolwater extraction at −5° C. produced oscillating fibres in a matter of a few days. The significant fact about such fibres appears to be their high elastic modulus.