Mt. Thebault et al., CYTOSOLIC ADENYLATE CHANGES DURING EXERCISE IN PRAWN MUSCLE, Comptes rendus de l'Academie des sciences. Serie 3, Sciences de la vie, 317(11), 1994, pp. 991-995
P-31 NMR and biochemical analysis were used to assess the effect of he
avy exercise on cytosolic adenylate levels in Palaemon serratus abdomi
nal muscle. At rest the MgATP level corresponded to 85.5% of the total
ATP content The cytosolic adenylate concentrations of the prawn muscl
e are considerably different from that of vertebrates The percentage o
f ADP bound to myofilaments was lower in the prawn muscle. Consequentl
y, the level of free cytosolic AMP was greatly higher (thirtyfold high
er) than in vertebrate muscle. During vigorous work, the concentration
of MgATP dropped and the cytosolic AMP accumulated, while the cytosol
ic adenine nucleotide pool decreased significantly. The phosphorylatio
n potential value and the ATP/ADP ratio, calculated from the cytosolic
adenylates, dropped acutely during the whole period of muscular contr
actions. On the contrary, the adenylate energy charge calculated from
the cytosolic adenylates decreased slightly. Therefore, even in muscle
displaying no AMP deamination, the adenylate charge is stabilized dur
ing exercise by the dynamic changes between cytosolic and bound adenyl
ate species.