Table 4.
High-energy phosphate compounds, intracellular pH, and PCr recovery kinetics
| HC-FF | PAD-FF | PAD-FF + 100% O2 | HC-RH | PAD-RH | PAD-RH + 100% O2 | |
|---|---|---|---|---|---|---|
| Rest | ||||||
| PCr, mM | 31 ± 1 (26–41) | 34 ± 2 (26–43) | 31 ± 2 (26–46) | |||
| Pi, mM | 1.5 ± 0.4 (1.1–2.2) | 1.5 ± 0.1 (0.8–2.1) | 1.8 ± 0.2 (0.6–2.4) | |||
| ADP, µM | 8.0 ± 0.2 (7.2–8.8) | 8.4 ± 0.2 (7.2–9.6) | 8.3 ± 0.3 (7.2–9.5) | |||
| pH | 6.96 ± 0.01 (6.92–7.00) | 6.98 ± 0.01 (6.92–7.04) | 6.98 ± 0.02 (6.92–7.04) | |||
| End-exercise and recovery parameters | ||||||
| PCr, mM | 14 ± 1 (8.1–16.9) | 13 ± 1 (6.5–19.3) | 15 ± 2 (7.3–18.8) | 11 ± 1 (5–15)† | 14 ± 1 (7–18)* | 14 ± 1 (7–19) |
| ADP, µM | 67 ± 1 (45–97) | 68 ± 4 (40–88) | 57 ± 5 (27–111) | 92 ± 11 (46–182)† | 78 ± 8 (46–134)* | 63 ± 12 (27–112) |
| pH min | 6.91 ± 0.01 (6.86–6.97) | 6.83 ± 0.06 (6.37–7.00)* | 6.75 ± 0.07 (6.42–7.00)*,† | 6.81 ± 0.04 (6.45–6.97)† | 6.81 ± 0.03 (6.69–6.99) | 6.91 ± 0.04 (6.67–7.00)* |
| pH end | 6.98 ± 0.01 (6.91–7.03) | 6.92 ± 0.03 (6.72–7.02)* | 6.90 ± 0.04 (6.71–7.05)* | 6.97 ± 0.02 (6.86–7.06) | 6.94 ± 0.02 (6.89–7.05) | 7.01 ± 0.02 (6.92–7.09)† |
| τ, s−1 | 48 ± 5 (31–96) | 90 ± 11 (33–164)* | 94 ± 18 (29–189)* | 45 ± 4 (27–78) | 86 ± 10 (58–147)* | 68 ± 12 (31–118)* |
| 95% Confidence interval | 8 ± 1 (5–15) | 13 ± 1 (6–18)* | 16 ± 2 (7–24)* | 6 ± 1 (2–10) | 12 ± 2 (8–22) | 10 ± 2 (5–21) |
Values are expressed as means ± SE with the range of minimum and maximum values in parentheses. HC, healthy control; FF, free flow conditions; PAD, peripheral artery disease; RH, reactive hyperemia; PCr, phosphocreatine; τ, PCr recovery time constant.
*
Significant difference between groups;
†
significant difference compared with the FF condition within group (P < 0.05).