Extremely low birth weight and reduced caloric intake have significant adverse effects on lung development and are risk factors for bronchopulmonary dysplasia. Vascular endothelial growth factor (VEGF) is highly involved in lung microvascular development, and may be affected by nutritional status. To test the hypothesis that suboptimal nutrition decreases VEGF signaling in formula-fed neonatal rats, and to determine whether supplementation with probiotics, prebiotics, or synbiotics ameliorate the effects, rat pups at birth (P0) were placed in room air (RA) or intermittent hypoxia (12%) during hyperoxia (50% O2) from birth to P3. The pups were either maternally-fed; or formula-fed with or without supplementation. Formula-fed pups were separated from their mothers at birth and hand-gavaged every 3 hours. Lung VEGF signaling was determined on P3. In RA, all formula-fed groups were significantly growth suppressed with decreased lung weights. Hyperoxia had a less remarkable effect on body weight; and mean lung weight was lower only in the unsupplemented formula-fed group. Lung VEGF was decreased in all formula-fed RA and hyperoxia groups, except the probiotics group. In RA, sVEGFR-1 levels were elevated in all formula-fed groups except the synbiotics group. However in hyperoxia, sVEGFR-1 levels were higher in the unsupplemented formula group. All genes involved in angiogenesis were downregulated in the formula-fed groups compared to maternally-fed. Formula feeding results in significant malnutrition associated with decreased lung size and lung VEGF levels in neonatal rat pups. Probiotic supplementation prevented the adverse effects of combined hyperoxia and suboptimal nutrition on lung VEGF suggesting preservation of angiogenesis.
Keywords: Corticosterone; VEGF; lungs; malnutrition; sVEGFR-1; stress.