Feto-maternal transfer and production of cortisol in the sheep

Dixon, Ross; Hyman, Alan; Gurpide, Erlio; Dyrenfurth, Inge; Cohen, H; Bowe, E T; Engel, Tibor; Daniel, Salha S.; James, Stanley L.; Wiele, Raymond Vande

doi:10.1016/s0039-128x(70)80154-4

Cited by 53 publications

(24 citation statements)

References 17 publications

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“…The placental production rate observed is substantially higher than reported estimates of maternal to foetal transfer of cortisol from studies with radioactive tracers in foetal sheep exteriorized or investigated 24 h after surgery [Beitius et al, 1970;Dixon, Hyman, Gurpide, Dyrenforth, Cohen, Bowe, Engel, Daniel, James and Wiele, 1970]. It is likely that the transfer rates reported here are higher than normal because of high (50-200 ng/ml) maternal plasma corticosteroid concentrations during the experiment.…”

Section: Discussioncontrasting

confidence: 59%

The Distribution and Clearances of Hormones and Metabolites in the Circulation of the Foetal Sheep

Jones

Rurak

1976

Exp Physiol

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Plasma hormone and metabolite concentrations have been measured in the plasma of blood collected simultaneously from the femoral artery, umbilical vein and carotid artery of the exteriorized foetal sheep. The concentration of vasopressin and catecholamines was consistently lower and of glucose, lactate and corticosteroids consistently higher in the umbilical vein compared with the femoral artery. ACTH concentrations showed no consistent pattern and fluctuated widely at each site, but during synacthen infusion the concentration in the umbilical vein was consistently lower than in the femoral artery. For corticosteroids the concentration in the carotid artery was much lower than that in the umbilical vein; the converse was true for catecholamines. Concentrations in the carotid and femoral artery were similar for all compounds investigated. These results indicate that the placenta is a major site of vasopressin, catecholamine and ACTH clearance and of glucose, lactate and corticosteroid production. The foetal liver is probably a major site of corticosteroid and catecholamine clearance.Many investigations of foetal development report the measurement of hormone and metabolite concentrations at single points in the foetal circulation [Bassett and Thorburn, 1969; Alexander, Britton, Nixon, Ratcliffe and Redstone, 1973; Liggins, Fairclough, Grieves, Kendall and Knox, 1973; Alexander, Bashore, Britton and Forsling, 1974; Boddy, Jones, Mantell, Ratcliffe and Robinson, 1974;Jones and Robinson, 1975] but little information on concentrations at various sites in the circulation is available. In the foetus the presence of parallel placental and systemic circulations [Dawes, 1968] suggests that substantial concentration differences may exist at different points in the vasculature. The extent of such differences depends on the sites of production and clearance. The liver and placenta are probably important in the clearance of hormones from foetal blood, but little quantitative information exists [Chard, Hudson, Edwards and Boyd, 1971;Broughton-Pipkin, 1972;Jones and Robinson, 1975; Jones, Luther, Ritchie and Worthington, 1975]. The present investigation describes simultaneous hormone and metabolite concentrations at several points in the foetal circulation and discusses the importance of the placenta and liver in hormone metabolism. METHODS

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Section: Discussioncontrasting

confidence: 59%

The Distribution and Clearances of Hormones and Metabolites in the Circulation of the Foetal Sheep

Jones

Rurak

1976

Exp Physiol

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“…The existence of a placental diffusion barrier has been documented in animal experiments (7,15). Our studies were carried out at birth and our results may reflect the fetal situation near term.…”

Section: Cortisol Transplacental Transfer Near Termmentioning

confidence: 60%

Cortisol Binding to Proteins in Plasma in the Human Neonate and Infant

et al. 1975

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“…Aldosterone MCR in pregnant ewes also appears to be higher than cortisol MCR which was determined in similar conditions (Paterson and Harrisson, 1968). As in dams, aldosterone MCR in fetuses was higher than cortisol MCR (about 124 1/24 hrs) (Beitins et al, 1970 ;Dixon et al, 1970 ;Liggins et al, 1973). The most striking result on aldosterone MCR was its abrupt decrease at the time of parturition (fig.…”

mentioning

confidence: 57%