Hormonal effects on amino acids and related compounds in plasma, amniotic fluid, and allantoic fluid of the chicken embryo

So far, more than 40 free amino acids and related compounds have been ident ified in plasma, amniotic fluid, and/or allantoic fluid of the 13-day chick en embryo. Concentration differences, and greatly varying behavior of these compounds under experimental conditions, revealed the presence of specific barriers among the three fluids. We tested the hypotheses that (1) the abs ence of an innervation of amnion and allantois indicates a hormonal control of their barriers, and (2) changes in the concentrations of certain amino compounds in the three fluids indicate anabolic or catabolic actions of hor mones. Insulin, prolactin, and stress caused complex changes of the concent rations of amino compounds in all three fluids within 30 min. Some of these changes indicated breakdown of embryonic tissues, while others must have b een due to transfer of amino compounds among the three fluid compartments. However, there was no significant effect on the glucose concentration in an y of the three compartments under any of the experimental conditions. This is the first demonstration of hormonal effects on the amino compounds in th e extraembryonic fluids of nonmammalian amniotes. (C) 1999 Academic Press.