Table 2.

Improved metabolic and contractile efficiency for working hearts of HSD-fed rats subjected to metabolic and hemodynamic stress

Parameter	Near-physiological milieu: 5 mM glucose, 0.4 mM oleate, 0.5 ng/ml insulin		Metabolic stress: 25 mM glucose, 0.8 mM oleate, 5 ng/ml insulin		Metabolic and hemodynamic stress: 40% rise in afterload + 1 μM epinephrine
	Chow	HSD	Chow	HSD	Chow	HSD
Glucose uptake (μmol/min/gdw)	5.24 ± 0.14	4.81 ± 0.24	9.51 ± 0.36	7.96 ± 0.39**	10.73 ± 0.67	7.91 ± 0.30***
Glucose oxidation (μmol/min/gdw)	0.40 ± 0.04	0.43 ± 0.03	1.05 ± 0.12	0.90 ± 0.10	1.50 ± 0.15	2.38 ± 0.17***
Lactate release (μmol/min/gdw)	5.20 ± 0.43	3.52 ± 0.21**	9.68 ± 0.41	8.81 ± 0.51	13.11 ± 0.53	12.40 ± 0.39
Glucose utilized (μmol/min/gdw)	5.60 ± 0.46	3.94 ± 0.22**	10.73 ± 0.44	9.71 ± 0.56	14.61 ± 0.57	14.79 ± 0.48
Oleate oxidation (μmol/min/gdw)	1.13 ± 0.06	1.13 ± 0.06	1.52 ± 0.07	1.58 ± 0.07	1.96 ± 0.12	2.29 ± 0.11*
Cardiac power (mW)	8.0 ± 0.4	8.8 ± 0.4	8.2 ± 0.4	9.1 ± 0.3	8.3 ± 0.5	9.8 ± 0.4*
Cardiac efficiency	0.83 ± 0.03	0.83 ± 0.04	0.82 ± 0.03	0.85 ± 0.04	0.54 ± 0.02	0.61 ± 0.03*

Isolated hearts were perfused as described in Fig. 4A. Lactate release is given in micromole glucose equivalents. Glucose utilized represents the sum of glucose released as lactate and being oxidized. Data are presented as means ± se from 5 chow-fed and 6 HSD-fed animals/group for rate of glucose uptake; 11 chow-fed and 9 HSD-fed animals/group for all other parameters. gdw, grams dry weight.

^*P < 0.05,

^**P < 0.01,

^***P < 0.001 vs. chow.