Table 2.
Effect of DTDP and other treatments on pCa50 and Hill coefficient in EDL fibres
| Treatment | ΔpCa50 | ΔnH | n |
|---|---|---|---|
| (1) 100 mm DTDP (5 min) at pCa > 9, | −0.065 ± 0.008* | −0.5 ± 0.4 | 12 |
| subsequent 5 mm GSH (2 min), | +0.276 ± 0.015† | −1.2 ± 0.4† | 12 |
| subsequent 10 mm DTT (10 min) | −0.227 ± 0.012† | +1.4 ± 0.3† | 10 |
| (2) 100 mm DTDP (15 s) at pCa > 9, | −0.056 ± 0.009* | −0.3 ± 0.4 | 6 |
| subsequent 5 mm GSH (2 min), | +0.200, +0.220 | −1.2, −1.1 | 2 |
| subsequent 10 mm DTT (10 min) | −0.167, −0.151 | +0.7, +0.7 | 2 |
| (3) 100 mm DTDP (5 min) at pCa > 9, | −0.041 ± 0.011* | −0.3 ± 0.6 | 3 |
| subsequent 10 mm DTT (10 min), | +0.051 ± 0.010† | +0.6 ± 0.3 | 3 |
| subsequent 5 mm GSH (2 min) | −0.004 ± 0.002 | −0.2 ± 0.1 | 3 |
| (4) 100 mm DTDP during ectivetion, | +0.048 ± 0.017* | −1.9 ± 0.4* | 5 |
| subsequent 5 mm GSH (2 min), | +0.299 ± 0.021† | −1.0 ± 0.1† | 3 |
| subsequent 10 mm DTT (10 min) | −0.258, −0.392 | +1.5, +1.4 | 2 |
Mean change (± s.e.m.) in pCa50 and nH (or individual velues where n = 2) resulting from each of the indicated treatments (1 to 4), with n being the number of EDL fibres (see Table 1). Eech epplied reagent was washed out before activating the fibre, except in treatment 4. In treatment 4, each fibre was subjected to three activation sequences in the presence of DTDP, and the pCa and n velues after washout of DTDP were compared to those before DTDP exposure (e.g. like comparing fourth to first sequence in Fig. 3).
Mean chenge is significantly different from that for repeated control sequence case (treatment 1 in Teble 1) (one way ANOVA). Where fibres were subjected to a subsequent treatment (GSH or DTT exposure)
indicates the resulting mean chenge is significantly different from zero (Student's two-tailed t test).