Table 1.

Cellular high-energy phosphates and O₂ carriers in the FDI and TA muscles of the two age groups

Compound	FDI		TA
	Adult	Elderly	Adult	Elderly
[PCr]	28.0 ± 1.0	24.5 ± 1.3*	28.6 ± 1.1	25.5 ± 1.8*
[ATP]	6.3 ± 0.4	4.5 ± 0.2*	7.0 ± 0.2	5.6 ± 0.2*
[ATP]/[PCr]	0.22 ± 0.01	0.18 ± 0.01*	0.24 ± 0.01	0.22 ± 0.01
[ADP]	0.027 ± 0.002	0.032 ± 0.004	0.025 ± 0.002	0.029 ± 0.004
[Pi ]	3.4 ± 0.4	2.4 ± 0.2	3.1 ± 0.2	2.9 ± 0.2
[Mb]	0.27 ± 0.01	0.24 ± 0.01*	0.44 ± 0.02	0.36 ± 0.05*
[Mb]/[PCr]	0.0096 ± 0.0003	0.0103 ± 0.0008	0.016 ± 0.001	0.013 ± 0.001
[Hb]	0.02 ± 0.01	0.03 ± 0.01	0.09 ± 0.02	0.17 ± 0.06*

Values are shown as the means ± SEM of millimolar concentrations.

*, Significant difference between adult and elderly groups.