Objectives: 

Maternal undernutrition during pregnancy causes low birth weight, which is associated with a higher risk of developing hypertension and cardiovascular disease later in life. Left ventricular hypertrophy and increased collagen are characteristic features of hypertension. We aim to determine if maternal undernutrition induces heart alterations in the offspring at an early age and to establish possible sex differences.

Materials: 

Rats were fed ad libitum with standard chow throughout gestation or restricted to 50 % from day 10 of gestation until birth. After birth the mother was back to ad libitum diet and the offspring was adjusted to 12 pups (C, control mother pups; R, restricted mother pups). The rats were used at the age of 7 days and at weaning (21 days). The rats were killed by decapitation; the heart was excised and the ventricles were weighted, fixed and parafine embedded for histological study with Masson-Trichromic stain. Statistical analysis was performed by Student´s t test.

Results: 

Both male and female R rats exhibited a lower body weight at both 7 and 21 days. At the age of 7 days the ventricular weight/body weight tended to be larger in R rats, but did not reach statistical significance in male (C=0.0063±0.0001, n=20; R=0.0067±0.0002; n=18) or female rats (C=0.0062±0.00001, n=25;R=0.0066±0.0002, n=21). Histological sections showed non-fibrous collagen in the interstitium from R rats (both males and females) which was almost absent in C rats. Intramyocardial arteries from R rats also exhibited a thicker wall compared to C rats. 21 day-old R rats exhibited significant ventricular hypertrophy in male (C=0.0051±0.0001, n=19; R=0.0059±0.0002; n=18; p<0.05) or female rats (C=0.0050±0.0001, n=20; R=0.0058±0.0002, n=28, p<0.05).

Conclusions: 

The early heart alterations induced by maternal undernutrition might participate in the development of ventricular fibrosis and stiffening associated to hypertension in the adult.(Supported by Ministerio de Ciencia e Innovación; FEM2009-13434-C02-02).