Table 1.

Left ventricle function parameters

Parameter	WT Ctrl	WT LPS	IL-37tg Ctrl	IL-37tg LPS	WT LPS + rIL-37
Heart rate (bpm)	430 ± 36	528 ± 56*	437 ± 29	520 ± 73#	510 ± 61*
Developed pressure (mmHg)	78.7 ± 7.8	47.0 ± 3.6*	80.0 ± 11	67.2 ± 7.4#†	65.3 ± 9.8†
End-systolic volume (μl)	8.0 ± 5.5	24.5 ± 2.9*	9.1 ± 2.2	14.9 ± 2.4#†	16.5 ± 2.8*†
End-diastolic volume (μl)	20.2 ± 3.9	31.1 ± 6.1*	20.6 ± 3.1	24.2 ± 2.9	25.1 ± 4.4
Ejection Fraction (%)	60.4 ± 9.0	21.2 ± 4.6*	55.8 ± 12	38.4 ± 5.3#†	34.3 ± 6.1*†
Cardiac output (ml/min)	5.3 ± 0.9	3.2 ± 0.3*	5.1 ± 1.2	4.7 ± 0.4†	4.4 ± 0.8†

WT and IL-37tg old mice were treated with lipopolysaccharide (LPS, 0.5 mg/kg, iv) or normal saline. In a separate group of WT old mice, recombinant IL-37 (rIL-37, 0.05 mg/kg, iv) was administered 30 minutes after injection of LPS. WT old mice had reduced left ventricle (LV) function, including the developed pressure, ejection fraction and cardiac output, at 6 hours after treatment with LPS. IL-37tg old mice displayed better LV function after treatment with LPS in comparison to WT old mice. Treatment with recombinant IL-37 also improved LV function in WT old mice exposed to LPS. Data are expressed as mean ± SD. n=6 mice in each group; one-tailed ANOVA;

^*P<0.05 vs. WT old control (Ctrl);

^#P<0.05 vs. IL-37tg old control;

^†P<0.05 vs. WT old mice treated with LPS alone.