Urethral and urachal urine output to the amniotic and allantoic sacs in fetal sheep

Abstract

A chronic fetal sheep preparation was developed to measure, without interruption in utero, urethral and urachal urine output to the amniotic and allantoic sacs, respectively. Fetal urethral, urachal and total urine output was measured during a 5 day post-operative period, in late gestation. Total fetal urine output increased from day 1 to a volume of 1216 ± 115 ml/day (SEM) on day 5 post-operative. Urachal urine output increased significantly from 12 ml/day on day 1 to 467 ml/day on day 5 (P < 0.05). Fetal arterial blood gases, pH and immunoreactive ACTH, cortisol and immunoreactive arginine vasopressin concentrations were stable throughout the 5-day recovery period. Fetal urachal urine outp..