Preterm birth in lambs: sleep patterns and cardio-respiratory changes.
Cardio-respiratory physiology in sleep was examined in eight preterm lambs born at 133-135 (134 +/- 1, mean SEM) days of gestation after 3-5 days of pulsatile ACTH/TRH infusion, and contrasted with eight lambs born at term (147 +/- 1 days). Lambs were instrumented with electrodes for recording electrocorticogram, electro-oculogram and nuchal electromyogram to define behavioural states, as well as carotid arterial catheters for determination of arterial pressure, heart rate and arterial blood gases. Compared to full-term lambs, the preterm lambs exhibited extended active sleep times, elevated PaCO2 and faster heart rate in all behavioural states than full-term lambs; with increasing postnatal age, sleep times and heart rate declined. As similar differences are found in preterm human infants, the preterm lamb will be a useful model to study the underlying physiology of these cardio-respiratory alterations.
Walker
A M
AM
Monash University, Centre for Early Human Development, Monash Medical Centre, Clayton, Australia.
de Preu
N D
ND
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology; D008954:Models, Biological; D011247:Pregnancy; D012756:Sheep; D012890:Sleep / Q000502:physiology*