Table 1.

Characteristics of tension-pCa relationships in rat myocardium at 1.9 and 2.2µm SLs, for cTnI(WT), cTnI(1–167), and cTnI(1–193) fibers (Mean± SEM)

	cTnI(WT)		cTnI(1–167)		cTnI(1–193)
	1.9µm	2.2µm	1.9µm	2.2µm	1.9µm	2.2µm
Tmin (mN mm−2)	1.00±0.06	3.74±0.26*	1.24±0.19	3.34±0.09*	0.67±0.03	2.15±0.29*†#
Tmax (mN mm−2)	13.25±1.75	31.25±0.62*	28.42±1.59†	47.96±1.37*†	13.38±1.07#	25.72±0.73*#
Tdev (mN mm−2)	12.25±1.50	27.51±0.54*	27.18±2.21†	44.62±1.29*†	12. 71±1.1#	23.5 7±0.69*#
pCa50	5.29±0.01	5.37±0.02*	5.44±0.01†	5.46±0.02†	5.39±0.01†#	5.48±0.02*†
nH	4.64±0.21	6.18±0.11*	8.15±0.39†	7.27±0.21†	4.68±0.15#	5.78±0.13*#
n fibers	6	6	7	7	6	6

T_min, absolute tension value at pCa 8.0; T_max, absolute tension value at pCa 4.8; T_dev, Ca²⁺-activated developed tension (T_max- T_min); pCa₅₀ and n_H represent fit parameters to a 3-parameter Hill equation.

^*Effect of SL for each truncation or wild-type; P <0.05

^†Truncation effect compared to cTnI(WT) at same SL; P <0.05

^#Difference between cTnI(1–193) and cTnI(1–167) at same SL; P <0.05