2c). Four seconds after the initial MVC, PT was 62.6 �� 10.8 Nm, a 45 �� 13% increase compared to the pre-MVC value (Figure 2a). There was a sharp decline in PT in the following 60 s so that PT after 2 min was not selleck chemicals Pacritinib significantly different (p>0.05) from the pre-MVC PT (Figure 2a). However, PT returned to baseline pre-MVC value only after 6 min. Figure 2 Time decay of PT (a), RTD & CT (b), and RR & ?RT (c) after a 5 s MVC in response to electrical stimulation reported as % change from unpotentiated values for study 1. * p< 0.05 for unpotentiated values. PT, peak twitch ... RTD and RR increased significantly (p<0.05) by 53 �� 13% and 50 �� 17%, respectively, immediately after the MVC whilst CT and ?RT were unchanged for the duration of the experiment (Figures 2b and and2c).2c).
RTD and RR returned to the pre-MVC values within 3 min after the initial MVC. The decay in PT was associated with a progressive fall in the RTD and in the RR (Figures 2b and and2c).2c). Correlation between PT vs RTD, PT vs RR and PT vs CT was r2 = 0.99 (p<0.001), 0.98 (p<0.001) and 0.56 (p<0.01), respectively, during the 10 min period after the MVC. EMD did not change at any time during this section of the experiment (data not shown). Study 2 Unpotentiated muscle: Torque response to repeated SS over 1 min SS torque response to the first 6 episodes of electrical stimulation (Figure 1c) delivered to the unpotentiated muscle in the min prior to the first MVC did not differ from each other (p>0.05) and the mean values did not differ from those of study 1. Mean values for PT, EMD, CT, ?RT, RTD and RR were respectively 43.
5 �� 12.9 Nm, 34.2 �� 3.1 ms, 85.9 �� 9.5 ms, 80.3 �� 10.5 ms, 0.52 �� 0.18 Nm/ms and 0.56 �� 0.21 Nm/ms (Table 2). Table 2 Responses of single stimulus at specific time points at rest for study 2 (n= 6) Potentiated muscle: Torque response to repeated SS after 10 MVCs PT immediately (4 s) after the first MVC (MVC 1) was increased by 56 �� 10% (Figure 3a) to 67.0 �� 17.7 Nm. PT immediately after MVCs 2�C10 was not different (p>0.05) from PT immediately after MVC 1 (Figure 3a). Figure 3 Time decay of PT (a), RTD & CT (b) and RR & ?RT (c) after a 5 s MVC in response to electrical stimulation reported as % change from unpotentiated values for study 2. * p< 0.05 from MVC 1. Other values were not different ... PT then decayed from 4�C45 s after each MVC so that at 16 s after MVC 1, PT fell significantly (p<0.
001) from the 4 s value PT, but PT was still 29 �� 7% above the unpotentiated value after 45 s. Interestingly the following MVCs showed similar PT at 4 s after MVC, but PT was significantly (p<0.05) higher 30 and 45 s after MVC 2 and 8, 12, 16, 30 and 45 s after MVC 5 and 10 compared to MVC 1, indicating a slower decay AV-951 of PT (Figure 3a). In addition PT at 45 s after the first MVC was significantly lower (p<0.05) than were the values 45 s after any of the following MVCs (2�C10).