Urinary endothelin excretion in the neonate: influence of maturity and perinatal pathology.

The present study was undertaken to establish the developmental pattern of urinary endothelin-1 (ET-1) excretion and to define its possible role in mediating pathophysiological changes related to perinatal asphyxia/infection and dopamine treatment. Urinary ET-1 levels were measured by radioimmunoassay in 7 full-term neonates (mean gestational age 39.3 weeks) on days 1, 3 and 5, and in 9 pre-term neonates (mean gestational age 30.8 weeks) on days 1, 3, 5, 7 and weekly thereafter for 5 consecutive weeks. The results were compared with those of three age-groups of 30 normal children (4-8 years, 9-12 years and 13-18 years); each group consisted of 10 children. The influence of severe cardiopulmonary distress (n = 16, mean gestational age 33.9 weeks, post-natal age 3.3 days) and dopamine administration in a dose of 2 micrograms/min per kg (n = 10, mean gestational and post-natal ages 32.1 weeks and 5.6 days, respectively) were also studied. In full-term infants, ET-1 concentration fell from 34.3 +/- 1.8 pmol/l on day 1 to 21.5 +/- 1.5 pmol/l on day 5 (P < 0.01). In premature infants its absolute value and its post-natal fall were similar in the 1st week and no further change occurred in weeks 2-5; it stabilized at levels between 17.1 +/- 2.2 and 16.7 +/- 1.7 pmol/l. These concentrations tended to be lower than those of 25.5 +/- 1.3, 23.0 +/- 1.0 and 26.2 +/- 0.7 pmol/l measured in three groups of older children.(ABSTRACT TRUNCATED AT 250 WORDS)