Table 3.

Ca²⁺- and Sr²⁺-activation parameters of diaphragm fibers activated at resting length and then with a stretch applied.

	0 min		127dGA
	Resting length	Stretched	Resting length	Stretched
pCa10	6.62 ± 0.03	6.74 ± 0.02*	6.65 ± 0.04	6.74 ± 0.01*
pCa50	6.40 ± 0.03	6.49 ± 0.00*	6.27 ± 0.02	6.35 ± 0.01*
pCa90	6.10 ± 0.02	6.13 ± 0.03	5.89 ± 0.02	5.93 ± 0.02
nCa	3.62 ± 0.10	3.54 ± 0.08	2.51 ± 0.13	2.36 ± 0.09
pSr50l	5.55 ± 0.04	5.93 ± 0.10†	5.40 ± 0.07	5.60 ± 0.03*
nSrl	1.68 ± 0.14	2.59 ± 0.22†	1.52 ± 0.14	1.64 ± 0.06
pSr502	4.70 ± 0.05	4.78 ± 0.02	4.96 ± 0.01	4.92 ± 0.04
nSr2	3.60 ± 0.24	3.25 ± 0.13	4.40 ± 0.47	4.52 ± 0.48
Fl (%)	33.82 ± 4.36	29.88 ± 6.85	52.76 ± 3.54	52.68 ± 1.69
SL (μm)	2.40 ± 0.05	2.92 ± 0.06†	2.29 ± 0.04	2.75 ± 0.08†

Values presented are the mean ± SEM. n = 3 animals (12 fibers) for both term and 127 day GA fetal sheep. Diaphragm fibers were first activated at resting length, and then under an induced stretch of ∼0.5 μm in sarcomere length (SL). *P < 0.05 and †P < 0.01 indicates significant differences compared to the data obtained at resting length.