Pulsatile release of oxytocin in newborn infants.
Recently, a pulsatile, basal oxytocin blood level has been described in human adults. To investigate if such a hormone profile exists already during the neonatal period, we collected blood samples continuously with 20-s fractions for 4 min in 1-day-old infants (n = 26). Plasma oxytocin concentrations were determined by a specific radioimmunoassay. The values were further analysed by the pulse detection program PULSAR. We found that 42% of the infants presented one peak in the oxytocin level during a 4-min period. The peak constituted a 111 +/- 66% (mean +/- SD) increment of the baseline value. It is suggested that the release of oxytocin during basal conditions occurs in a pulsatile way in newborn infants and that these hormone pulses reflect fluctuations in the activity of the hypothalamic neurosecretory cells.
Marchini
G
G
Department of Woman and Child Health, Karolinska Institute, Stockholm, Sweden.
Stock
S
S
D005260:Female; D006801:Humans; D007231:Infant, Newborn / Q000378:metabolism*; D008297:Male; D010121:Oxytocin / Q000378:metabolism*; D011863:Radioimmunoassay; D012636:Secretory Rate
D010121:Oxytocin