ENDOTHELIN-1-21 PLASMA-CONCENTRATIONS ON DAY-1 AND DAY-4 OF LIFE IN HEALTHY AND ILL PRETERM NEONATES

Endothelins (ETs) are highly vasoconstrictive 21-amino acid peptides p ossessing also cell-proliferative properties. They have been implicate d in a variety of perinatal pathologic conditions, and their plasma co ncentrations have been found elevated in humans at birth. The purpose of this study was to determine ET 1-21 plasma concentrations in health y and ill preterm infants and to investigate possible concentration ch anges with time from birth in cases of normal and abnormal adaptation to extrauterine life. The study comprised 36 preterm infants. Twenty-e ight, comprising group A, were healthy (22/28) or minimally affected ( 6/28) and 8, comprising group B, were moderately (2/8) or severely ill (6/8) requiring continuous positive ah-way pressure or intermittent p ositive pressure ventilation as well as surfactant administration. Ah infants in group B had intraventricular hemorrhage grade greater than or equal to II. Venous blood from all neonates was drawn on days 1 and 4 and ET 1-21 plasma concentrations were determined by radioimmunoass ay (Amersham kit RPA 5559). ET 1-21 plasma concentrations were on day 1: 16.25 +/- 8.14 and 21.81 +/- 5.87 and on day 4: 12.89 +/- 4.56 and 16.16 rh 5.43 pmol/l, for groups A and B, respectively. The statistica l analysis showed a significant reduction in plasma ET concentrations on day 4 in both groups (p = 0.009 and p = 0.025, respectively). Never theless, ET 1-21 plasma concentrations were on day 4 significantly hig her in ill preterm infants presenting symptoms from tissues involved i n the elimination of ETs from the circulation as well as in their prod uction.