. Author manuscript; available in PMC: 2016 Jan 1.

Published in final edited form as: Respir Physiol Neurobiol. 2014 Oct 24;0:47–52. doi: 10.1016/j.resp.2014.10.011

Table 1.

Diaphragm twitch and tetanic force-frequency characteristics.

	WT		p47^{phox(−/−)}

	vehicle	SMase	vehicle	SMase
TPT (ms)	15.9 ± 1.1	15.5 ± 0.8	16.3 ± 1.0	15.3 ± 0.5
½ RT (ms)	13.0 ± 0.8	12.6 ± 0.5	13.5 ± 1.0	13.3 ± 0.5
Max +dP/dt (N/cm²·s)	284 ± 55	227 ± 38^*	315 ± 34	271 ± 48
(+dP/dt)/P_t (s⁻¹)	67 ± 2	68 ± 1	66 ± 2	67 ± 1
F₅₀ (Hz)	52 ± 2	60 ± 2^*	52 ± 3	57 ± 2
nH	3.52 ± 0.13	3.89 ± 0.09	3.30 ± 0.09	3.95 ± 0.17^†

TPT, time to peak tension; ½ RT, on-half relaxation time; maximal rate of specific force development during twitch; Pt, peak twitch force F₅₀, stimulus frequency that elicits 50% maximal force; nH, Hill coefficient (~ slope of force-frequency relationship). P_t force is shown in Fig. 3. Data are mean ± SE. For WT, n = 8 mice per group. For p47^{phox(−/−)}, n = 4 (vehicle) and n = 7 mice (SMase).

P < 0.05 vs. WT vehicle;

^†

P < 0.05 vs. p47^{phox(−/−)} vehicle