SUPEROXIDE ANION RELEASE BY POLYMORPHONUCLEAR LEUKOCYTES IN WHOLE-BLOOD OF NEWBORNS AND MOTHERS DURING THE PERIPARTAL PERIOD

Superoxide anion (.O-2(-)) production was investigated in whole blood of mothers in the peripartal period and in neonates. Blood samples from 14 mothers undergoing vaginal delivery (VD) were tested at the beginning of labor, during labor, after delivery, and 4 d after delivery. Nine mothers undergoing elective cesarean section (ECS) were tested before anesthesia, after extraction of the fetus, and 4 d later. Seventy-two healthy, full-term newborn infants were examined at birth and on the fourth day of life. Red cell glutathione peroxidase, catalase, glutathione reductase, and superoxide dismutase activities were also measured at birth and on the fourth day of life in 26 of the 72 neonates. Higher .O-2(-) levels were detected in mothers undergoing VD compared with ECS (p < 0.05). A significant decrease was detected in zymosan-stimulated .O-2(-),production between cord and fourth-day blood samples in both VD- and ECS-delivered infants (p < 0.01). Zymosan-stimulated samples showed higher values after VD than ECS, both in cord blood (p < 0.004) and on the fourth day of life (p < 0.006). A positive correlation was found be tween .O-2(-) release in zymosan-stimulated cord blood and that found in the mothers at the beginning of labor (r = 0.654; p < 0.01), during labor (r = 0.721; p = 0.008), and after delivery (r = 0.832; p = 0.0008). A positive correlation was also found between .O-2(-),- release and glutathione peroxidase on the fourth day (r = 0.709, p = 0.014). The results of the present investigation demonstrate the role of peripartal events in modulating free radical release by polymorphonuclear leukocytes during the perinatal period.