Decreased Plasma Arachidonic Acid Binding Capacity in Neonates

Abstract

Arachidonic acid (AA) metabolites have been implicated in neonatal pathologic states such as respiratory distress syndrome (RDS). Since free (nonprotein bound) AA is the substrate for synthesis of these compounds, a decreased capacity to bind AA in neonatal plasma could contribute to these disorders. AA binding was assayed by equilibrium dialysis in plasma samples from healthy adults and various infant groups. Plasma from these infant groups bound significantly less AA than adult plasma. Premature infants with RDS and premature infants receiving intralipid had the lowest capacity to bind AA. The increased availability of free AA may be important in neonatal pathophysiologic states involving arachidonate metabolites.

Formation of Hydroxyeicosatetraenoic Acids (HETE) in Blood From Adults Versus Neonates: Reduced Production of 12-HETE in Cord Blood

“…It is possible that some component of neonatal serum further reduces the concentration of arachidonic acid available to the enzyme. However, it is unlikely that this arachidonic acid sink is plasma albumin or another plasma protein because we have previously shown that plasma from neonates has less "binding capacity" for arachidonic acid than that found in adult plasma (23).…”