Phosphorylcreatine and ATP changes during shortening and lengthening of stimulated muscle
(1964) Archives Internationales de Physiologie et de Biochimie — Vol. 72, n° 2, p. 306-309 (1964)
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- Authors
Maréchal, Georges 
- Abstract
- Sartorius muscles of male Rana. temporaria, were poisoned with 0.4 mM iodoacetate for 1 hour and mounted in a fast freezing apparatus. They (n=156) were frozen in isopentane, cooled with liquid nitrogen, ground in stainless steel cartridges, and extracted with perchloric acid and analyzed for free and bound creatine, and ATP, after six tetani of 3s at 2°C in nitrogen atmosphere. The excess hydrolysis of PC associated with a positive work of 33.7 ± 1.6 mcal/g is 2.17 ±0.59 micromoles/g and 0.88 + 0.21 micromole ATP/g. The mechanochemical coefficient estimated from these figures is 11.1 kcal/mole. The stretched muscles (0.23 cm/sec) have more PC than the isometrically stimulated muscles: 1.68 ± 0.59 micromole/g (t = 2.84; P < 0.01) and less free creatine: -2.25 ± 0.55 micromoles/g (t = 4.1; P < 0.001). The ATP level has not changed. The spared 1.7 micromole PC/g are a reserve of 19 mcal/g (assuming 11kcal/mole as a mechanochemical coefficient for positive work). This is about 30 % of the mechanical energy which has been fed into the muscle (5.4 mcal/g/ sec).
Citations
Maréchal, G. (1964). Phosphorylcreatine and ATP changes during shortening and lengthening of stimulated muscle. Archives Internationales de Physiologie et de Biochimie, 72(2), 306-309. https://doi.org/10.3109/13813456409058976 (Original work published 1964)