Cerebral protein synthesis in the ovine fetus near term with amino acid infusion and insulin-induced hypoaminoacidemia.

Background: Studies during early development have shown that the precursor availability of amino acids directly affects protein synthesis both at the whole-body level and for select organ tissues, although this has not been studied for the brain.

Objective: We utilized a mixed amino acid infusate and an insulin euglycemic clamp technique in the ovine fetus near term, with increases and decreases in circulating amino acid levels of ∼30 to 40% on average, and determined the impact on cerebral protein synthesis.

Methods: Fetal sheep received a 6-hour infusion of Primene® 10% (amino acid infusate group) or a co-infusion of insulin and 10% dextrose (insulin/dextrose infusate group) together with a continuous infusion of L-[1-(13)C]-leucine.

Induced hyper and hypo amino acidemia in the ovine fetus near term: effects on electrocortical activity.

Amino acid infusate (Primene) and insulin euglycemic (insulin + 10% dextrose) clamp techniques were used in the ovine fetus near term and the impact on the incidence of low-voltage and high-voltage electrocortical (ECOG) activities was determined. Fetal sheep were studied over a 2-hour control period and a subsequent 6-hour experimental period.With the Primene infusion, the basic and neutral amino acids were increased by 43% and 25%, respectively, whereas the acidic amino acids showed little change.