Vitamin C Prevents Intrauterine Programming of in vivo Cardiovascular Dysfunction in the Rat

Abstract

Background: Fetal hypoxia is common and in vitro evidence supports its role in the programming of adult cardiovascular dysfunction through the generation of oxidative stress. Whether fetal chronic hypoxia programmes alterations in cardiovascular control in vivo, and if these alterations can be prevented by antioxidant treatment, is unknown. This study investigated the effects of prenatal fetal hypoxia, with and without maternal supplementation with vitamin C, on basal and stimulated cardiovascular function in vivo in the adult offspring at 4 months of age in the rat. Methods and Results: From days 6 to 20 of pregnancy, Wistar rats were subjected to Normoxia, Hypoxia (13% O₂), Hypoxia+Vitamin C (5mg/ml in drinking water) or Normoxia+Vitamin C. At 4 months, male offspring were instrumented under urethane anaesthesia. Basal mean arterial blood pressure, heart rate and heart rate variability (HRV) were assessed, and stimulated baroreflex curves were generated with phenylephrine and sodium nitroprusside. Chronic fetal hypoxia increased the LF/HF HRV ratio and baroreflex gain, effects prevented by vitamin C administration during pregnancy. Conclusions: Chronic intrauterine hypoxia programmes cardiovascular dysfunction in vivo in adult rat offspring; effects ameliorated by maternal treatment with vitamin C. The data support a role for fetal chronic hypoxia programming cardiovascular dysfunction in the adult rat offspring in vivo through the generation of oxidative stress in utero.  (Circ J 2013; 77: 2604–2611)