Purpose
In preterm human infants, risk of retinopathy of prematurity (ROP) has been linked to small for gestational age, low circulating levels of insulin-like growth factor-1 (IGF-1) and slow postnatal weight gain. To prevent severe ROP, postnatal nutrition in preterm infants is very important. The aim of this study is to investigate prenatal and postnatal nutrient effects on body weight gain, retinal vascularization and IGF-1 in plasma in neonatal rat pups.
Methods
Sprague-Dawley rat dams were fed either an unrestricted, isocaloric normal protein (20%) or low protein (10%) diet to cause pup growth restriction from 7 days before gestation. The same diet was continued after the birth of pups. Neonatal rat pups were divided in two groups after birth, smaller litters (7 rats) and larger litters (14 rats) to cause postnatal growth retardation. On day 8, after measuring body weight, the rat pups were sacrificed and blood samples were collected. Retinas were dissected, stained with adenosine diphosphatase and flat-mounted. The total retinal area (TRA) and vascularized retinal areas (VA) were measured. Concentration of IGF-1 in plasma was measured with ELISA. These results were compared in 20%-7rats, 20%-14rats, 10%-7rats and 10%-14rats groups. Statistical analyses were performed with Mann-Whitney’s U test and Kruskal-Wallis test. P value <0.05 was considered significantly.
Results
The pups from dams fed the low protein diet weighted significantly lighter at birth (5.8±0.1g vs. 6.8±0.2g P<0.001). The results on day 8 were shown in table.
Conclusions
Prenatal and postnatal undernutrition may delay postnatal retinal vascularization and retinal development, and cause low concentration of IGF-1 in Plasma.
Keywords: 698 retinal development •
618 nutritional factors •
706 retinopathy of prematurity