Deficiency of plasma PGI2-like regenerating activity in neonatal plasma. Reversal by vitamin E in vitro.

Blood from full-term newborns was compared to adult blood for its ability to regenerate prostaglandin I2 (PGI2)-like activity from vascular tissue. The neonate possesses a markedly decreased ability to regenerate PGI2 (0.10 4/- 0.07 ng/mg vascular tissue) when compared to the adult (0.42 +/- 0.12). This decreased activity was not due to the presence of an inhibitor in neonatal blood. The impaired ability of neonatal blood to regenerate PGI2-like activity was related to its markedly decreased antioxidant potential and was corrected (0.34 +/- 0.08 ng/mg vascular tissue) by the addition of Vitamin E in vitro. Plasma PGI2-like regenerating activity had normalized by 3 to 5 months of age (0.41 +/- 0.11 ng/mg).