Vascular Dysfunction in a Rat Model of Prematurity After O2 Supplementation

Infants born prematurely are at an increased risk of cardiovascular diseases as they age. Oxygen supplementation during this critical window is necessary to sustain life because the lungs are under-developed, however, it is thought that high oxygen exposure may generate excessive superoxide contributing to oxidative stress. Using a rat model of prematurity, we tested the hypothesis that perinatal oxygen supplementation would increase aortic stiffness due to oxidative stress within the arterial wall. Immediately upon birth, 20 Sprague-Dawley pup rats were placed into environmental chambers with either 21% (control) or 80% oxygen (experimental) for eight days. All rats were aged until ~12 months, and blood pressure and pulse wave velocity (PWV) were measured. PWV was significantly higher in rats that were exposed to 80% oxygen after birth (371 ±13.25 vs 487 ± 27.84, p