Table 1.

Baseline Organ Masses and Echocardiographic Parameters of 8- and 15-Month-Old Male Mice

Genotype	8 Months		15 Months
	WT	LZM	WT	LZM
n	9	11	5	13
Body weight (g)	38.7±1.4	38.7±2.0	39.3±3.7	41.2±7.3
LV (mg)	94.7±3.0	106.4±5.0	112.6±6.8	140.2±7.1*,†
RV (mg)	22.8±1.0	5.0±1.6	29.0±1.9‡	31.9±1.5†
RV/tibia length (mg/cm)	12.5±0.5	13.7±0.9	15.7±1.0‡	17.5±7.5†
Tibia length (cm)	1.8±0.01	1.8±0.01	1.9±0.05‡	1.8±0.02§
LV/body weight (mg/g)	2.5±0.1	2.8±0.11	2.9±0.2	3.4±0.1
RV/body weight (mg/g)	0.6±0.03	0.7±0.05	0.8±0.1	0.8±0.04
Heart rate (s−1)	468.3±19.0	481.1±14.1	510.0±16.4	450.0±17.7

Note. WT = wild type; LZM = leucine zipper mutant; LV = left ventricle; RV = right ventricle.

*p < .01 vs 15-month WT.

^† p < .01 vs 8-month LZM.

^‡ p < .05 vs 8-month WT.

^§ p < .05 vs 8-month LZM.