Table 1.
Treatment set | Twitch peak (%) | Tetanus peak (%) | RP (ms) | |
---|---|---|---|---|
1. | Control | 100 (3) | 100 (3) | 4.7 ± 0.3 (3) |
100 μm SNAP | 98.4 ± 2.2 | 99.7 ± 0.9 | 4.3 ± 0.3 | |
2. | Control | 100 (6) | 100 (6) | 4.6 ± 0.3 (6) |
2 mm SNAP | 58.5 ± 5.9* | 82.4 ± 4.8* | 4.2 ± 0.2 | |
10 mm DTT | 79.4 ± 10.1*† | 91.6 ± 3.5*† | (not examined) | |
3. | Control | 100 (7) | 100 (6) | 4.2 ± 0.2 (6) |
10 mm SNAP | 54.2 ± 9.2* | 88.3 ± 4.3* | 4.3 ± 0.2 | |
10 mm DTT | 86.9 ± 7.8† | 101.9 ± 3.0† | 4.0 ± 0.3 | |
4. | Control | 100 (3) | 100 (3) | 4.3 ± 0.3 (3) |
100 μm DTDP | 69.8 ± 5.5* | 95.8 ± 0.4* | 4.0 ± 0.0 | |
5 mm GSH | 157.7 ± 5.8* | 111.4 ± 5.6 | 4.0 ± 0.0 | |
10 mm DTT | 99.0 ± 2.4† | 91.2 ± 14.9 | 4.3 ± 0.3 | |
5. | Control | 100 (5) | 4.2 ± 0.2 (5) | |
10 mm H2O2 (5 min) | 108.2 ± 4.6 | (not examined) | 4.2 ± 0.2 | |
6. | Control | 100 (9) | 100 (9) | 4.6 ± 0.3 (5) |
2 mm GSNOdel. | 65.2 ± 4.7* | 91.2 ± 2.1* | 4.4 ± 0.3 | |
10 mm DTT | 89.7 ± 5.4† | 96.5 ± 4.5 | 4.2 ± 0.2 | |
7. | Control | 100 (4) | 100 (4) | 4.5 ± 0.5 (4) |
100 μm GSNOimm. | 111.0 ± 6.9 | 102.3 ± 6.0 | 4.3 ± 0.6 | |
8. | Control | 100 (20) | 100 (17) | 3.5 ± 0.6 (9) |
2 mm GSNOimm. | 81.3 ± 8.7* | 84.8 ± 5.5* | 3.2 ± 0.6 |
Data are mean ±s.e.m. values of given parameter after the indicated treatment expressed relative to initial control level prior to any treatment. Fibres given up to three different successive treatments, as indicated in the given group; number of fibres (n) shown in brackets. Twitch and tetanic force in control conditions were 27 ± 4% (n = 57) and 92 ± 2% (n = 48), respectively, of maximum Ca2+-activated force (at pCa 4.5). The repriming period (RP), a measure of the AP refractory period, was measured as the minimum interpulse interval between a pair of pulses needed to elicit >50% of maximal incremental increase in twitch size (see Fig. 3C).
Significant difference (P < 0.05) between value for indicated treatment relative to initial control level.
Value following DTT treatment significantly different from preceding value.