Enhanced monocyte chemoattractant protein-1 production in aging mice exaggerates cardiac depression during endotoxemia

Table 1 Left ventricle function parameters

Parameter	Control		LPS		LPS + KC NAb		LPS + MCP-1 NAb
Parameter	Adult	Old	Adult	Old	Adult	Old	Adult	Old
Heart rate (bpm)	430 ± 13	427 ± 15	490 ± 25*	530 ± 23*	481 ± 18*	508 ± 20*	492 ± 30*	501 ± 20*
Developed pressure (mmHg)	83.0 ± 5.0	79.0 ± 3.5	57.0 ± 2.0*	46.0 ± 1.9*^†	62.0 ± 4.5*	51.1 ± 5.0*^†	73.1 ± 4.0*^#	68.2 ± 2.7*^#
End-systolic volume (μL)	7.0 ± 2.3	8.1 ± 2.5	18.0 ± 2.0*	24.5 ± 2.2*^†	18.2 ± 1.5*	23.5 ± 1.1*^†	11.0 ± 1.0*^#	15.0 ± 1.5*^†#
End-diastolic volume (μL)	21.0 ± 1.5	20.1 ± 1.7	27.0 ± 1.8*	30.1 ± 2.8*	28.0 ± 1.5*	30.1 ± 3.1*	22.0 ± 1.1^#	24.0 ± 1.8^#
Ejection fraction (%)	66.1 ± 4.2	60.0 ± 4.8	33.1 ± 2.8*	20.0 ± 1.8*^†	37.1 ± 2.5*	22.1 ± 1.8*^†	49.1 ± 3.7*^#	39.0 ± 2.6*^†#
Cardiac output (mL/min)	5.9 ± 0.4	5.2 ± 0.4	4.4 ± 0.3*	3.0 ± 0.2*^†	4.8 ± 0.3*	3.3 ± 0.3*^†	5.4 ± 0.3^#	4.5 ± 0.4^#

Mice were treated with lipopolysaccharide (LPS, 0.5 mg/kg) for 6 h. Both adult and old mice displayed significantly reduced left ventricle (LV) function. Old mice displayed worse LV performance, including developed pressure, ejection fraction and cardiac output, compared with adult mice. Treatment with monocyte chemoattractant protein-1(MCP-1)-neutralizing antibody (NAb) improved LV function in both adult and old mice, and old mice had a greater improvement. In contrast, neutralization of keratinocyte chemoattractant (KC) had a minimal effect on LV function. Data are expressed as mean ± standard error. ^*P <0.05 versus corresponding control; ^†P <0.05 versus adult mice with the same treatment; ^#P <0.05 versus LPS alone.

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