Table 2.
Parameters of Respiratory Function in Treated mdx Mice Compared with Vehicle Control mdx Mice
| Variable† | Wild type | Vehicle | 1D11 | Losartan | 1D11 + Losartan |
|---|---|---|---|---|---|
| Penh | 0.54 ± 0.02⁎⁎ | 1.3 ± 0.16 | 0.68 ± 0.04⁎⁎ | 0.76 ± 0.07⁎⁎ | 0.67 ± 0.05⁎⁎ |
| F, breaths/m | 323 ± 15⁎⁎ | 238 ± 17 | 286 ± 13⁎ | 312 ± 15⁎ | 261 ± 13⁎ |
| PIP, mL/s | 6.9 ± 0.51⁎⁎ | 4.78 ± 0.5 | 6.56 ± 0.4⁎ | 6.53 ± 0.3⁎ | 5.08 ± 0.3 |
| Ti, s | 0.063 ± 0.06⁎⁎⁎ | 0.168 ± 0.21 | 0.078 ± 0.004⁎ | 0.067 ± 0.05⁎⁎ | 0.088 ± 0.067 |
| EIP, ms | 4.45 ± 0.05⁎⁎ | 4.7 ± 0.02 | 4.53 ± 0.11⁎ | 4.6 ± 0.06⁎ | 4.63 ± 0.08⁎ |
| MV, ± mL/m | 77.8 ± 6.4⁎⁎ | 50.8 ± 5.9 | 70.9 ± 4.90⁎ | 74.4 ± 2.6⁎⁎ | 63.8 ± 3.7 |
| PEP, mL/m | 3.89 ± 0.3 | 3.04 ± 0.28 | 3.7 ± 0.23 | 3.74 ± 0.13 | 2.91 ± 0.17 |
| Te, s | 0.17⁎⁎ | 0.25 | 0.24 | 0.18⁎⁎ | 0.24 |
| TV, mL | 0.246 ± 0.01 | 0.218 ± 0.01 | 0.247 ± 0.03 | 0.242 ± 0.007 | 0.232 ± 0.008 |
| Tr, s | 0.101 ± .007 | 0.101 ± .004 | 0.115 ± .006 | 0.082 ± 0.01 | 0.111 ± 0.02 |
| EEP, ms | 35.5 ± 4 | 55.7 ± 8 | 43.1 ± 5 | 55.1 ± 6 | 43.8 ± 5 |
Respiratory function was measured by plethysmography in 9-month-old mdx mice treated with vehicle, 1D11, losartan, or a combination of 1D11 and losartan. Data are reported as means ± SE, with n = 8 for the vehicle-treated mdx and wild-type groups at the end of the study and n = 9 for the other treatment groups.
P < 0.05,
P < 0.01, and
P < 0.001, by analysis of variance followed by Dunnett's multiple comparison test relative to vehicle control.
EEP, end inspiratory pause; EIP, end inspiratory pause; f, frequency of breaths; MV, minute volume; Pause = (Te minus Tr)/Tr, calculated with Buxco plethysmography software (version 0.0; Wilmington, NC) for each recorded breath; Penh, enhanced pause [calculated for each recorded breath, using Buxco plethysmography software, version 0.0, as Penh = (PEP/PIP) × Pause]; PEP, peak expiratory flow; PIP, peak inspiratory flow; Te, expiration time (from start of expiration to end of expiration); Ti, inspiration time (from start of inspiration to end of inspiration); Tr, relaxation time (from start of expiration to the time-point at which 64% of the total expiratory pressure occurred); TV, tidal volume.