Postnatal Undernutrition (PUN) Permanently Alters the Heart to Reduce Maximal Exercise Capacity in Female Mice

Undernutrition during development increases the risk for adult cardiovascular disease. To determine if PUN alters heart structure function, and maximal exercise capacity in adulthood, newborn control mouse pups were fostered to dams fed a control (CON; 20% protein) or a protein-restricted diet (PUN; 8% protein; n=7-10 litters/treatment). At 21 d (PN21) pups were fed the CON diet ad lib. At PN70 a maximal treadmill test was performed to determine VO2peak; maximal vertical work was calculated for the final 30 sec. At PN80 cardiac function was evaluated by echocardiography. VO2peak was the same in CON and PUN mice and higher in males than females (249 + 9 and 169 + 6 ml/hr, respectively, P<0.001); gender x diet, NS. Maximal vertical work at VO2peak was higher in CON than PUN females (1.64 + 0.07 and 1.33 + 0.06 J/min, respectively, P < 0.01) but not males; gender x diet, P<0.02. Resting cardiac output was higher in CON than PUN offspring (18.8 + 0.7 and 16.3 + 0.7 ml/min, respectively; P<0.02) and in males t...