Placental transfer of epinephrine

Arachidonic acid and other free fatty acid changes during abortion induced by prostaglandin F2alpha

Serum free fatty acids (FFA's) were measured after intra-amniotic injection of prostaglandin F2alpha (PGF2alpha) for the induction of abortion in eight healthy women in the midtrimester of pregnancy. The total FFA levels increased in all cases during the period between PGF2alpha administration and abortion. This lipolysis most likely is secondary to the effect of the catecholamines as indicated by the temporal relationship between increased plasma and urine catecholamine and serum FFA levels. The percentage of arachidonic acid in the total amount of FFA's decreased after administration of PGF2alpha. This proportional decrease in arachidonic acid (p less than 0.05) may be due to selective utilization for the production of endogenous prostaglandins.

Substrate mobilization: a new hypothesis for the aetiology of the idiopathic respiratory distress syndrome

This hypothesis for the aetiology of the idiopathic respiratory distress syndrome of the newborn (IRDS) proposes that, although the aetiology is multifactorial, the factor of prime importance is the mobilization of substrate for surfactant synthesis. All factors known to influence the incidence, treatment, and prognosis of the IRDS can be shown to be associated with the mobilization of substrate and thereafter its continued availability for the synthesis of adequate surfactant. Thus factors which promote an antenatal increase in the breakdown of energy stores will be associated with a reduced incidence of the IRDS. On the other hand, despite adequate mobilization, factors associated with a lack of substrate secondary to poor transport of substrate, a reduction in pulmonary circulation or an alteration in fetal or neonatal metabolism which involves an increased utilization of substrate to provide energy, will be associated with an increased incidence of the IRDS.