PubMed HealthSearch

Biomedical subjects

F Cockburn

Publications and source records attributed to F Cockburn.

At least 91 records · Page 5Linked to original sources

Free amino-acid concentrations in fetal fluids.

The pattern of free amino-acid concentrations in maternal venous plasma, fetal umbilical arterial plasma, fetal urine, and amniotic fluid at 15 to 20 weeks' gestation has been determined. Free amino-acid concentrations were greater in fetal plasma than in maternal plasma, amniotic fluid, or fetal urine.The ratios of amino-acid concentrations in fetal umbilical arterial plasma and urine indicate that the fetal kidney can effectively conserve amino-acids, possibly reaching an adult level of competence in this respect.There was little correlation between amino-acid concentrations in the fluids analysed with the exception of that between amniotic fluid and fetal urine.

Amino Acids

Pulmonary vasoconstriction in asphyxia during cross-circulation between twin foetal lambs.

1. The effect of asphyxia on pulmonary vascular resistance was measured in anaesthetized foetal lambs whose left lung was supplied with arterial blood from a twin, both still being attached to their placentas by intact umbilical cords.2. In foetal lambs of 91-92 days gestation asphyxia of the recipient caused no pulmonary vasoconstriction so long as its left pulmonary artery was supplied with normal blood from a twin donor. Asphyxia of the donor caused pulmonary vasoconstriction in the unasphyxiated recipient; this was therefore wholly due to a local effect of the blood passing through the lung.3. In foetal lambs of 98-142 days gestation asphyxia of the recipient caused a small degree of pulmonary vasoconstriction, even though the left pulmonary artery was supplied with normal blood from the twin donor. This vasoconstriction was abolished by administration of hexamethonium or by cutting the sympathetic nerves to the left lung.4. In mature foetal lambs pulmonary arterial inflow and venous outflow were measured simultaneously. Broncho-pulmonary blood flow was less than 5% of total pulmonary flow. Pulmonary O(2) consumption was 0.75 +/- 0.11 ml./100 g.min, or about 5% of total foetal O(2) consumption.

Animals