Circulating Levels of Corticosterone in the Serum of Developing Chick Embryos and Newly Hatched Chicks

Abstract

Circulating levels of corticosterone were determined in chick embryos from 10 to 21 days of incubation using eggs from a Leghorn breeder flock. In Experiment 1, eggs were incubated from 10 to 20 days for daily embryonic blood collection. To verify stage of development with day of incubation, embryo right middle toe lengths were measured concurrent with blood sampling. Serum from three embryos was pooled into one sample and the corticosterone content of 10 samples per day of incubation was determined using a radioimmunoassay procedure. The levels of corticosterone from day 10 to 14 fluctuated slightly and then increased rapidly until 16 days of incubation. At this time serum corticosterone remained relatively constant through day 18 with an apparent increasing trend up to day 20. The use of toe lengths to assure no day-to-day overlap in embryonic development proved effective. In Experiment 2, newly hatched (day 21) chicks were sorted into four 3-hr periods ranging from early to late hatching. Blood samples were collected from five individual chicks during four 15-min sampling periods for each of the four hatch times. Serum corticosterone levels were not affected by sampling periods or hatch times.

Expression and regulation of glucocorticoid-induced leucine zipper in the developing anterior pituitary gland

“…This expression pattern is consistent with in vivo regulation of GILZ in the anterior pituitary by glucocorticoids, as circulating corticosteroids increase between e12 and e17 in the developing chicken embryo (Scott et al 1981, Jenkins et al 2007. Corticosterone (CORT), the predominant glucocorticoid in rodents and birds, increases 100-fold during chicken embryonic development, from subnanomolar concentrations on e10 (0 .…”

“…In the developing chicken embryo, circulating glucocorticoids increase from subnanomolar concentrations on e12 to 1-5 nM on e14, and increase further to 40-50 nM on e17 before decreasing slightly on e20 (Scott et al 1981, Jenkins et al 2007. After hatch, circulating glucocorticoids remain in the 10-30 nM range during the first week of neonatal life, with serum levels peaking on d1, and declining through d4 before rising again on d5 (Latour et al 1995).…”

Perinatal Deletion of B Cells Expressing Surface Ig Molecules That Lack V(D)J-Encoded Determinants in the Bursa of Fabricius Is Not Due to Intrafollicular Competition

“…4C and 5B). The mechanism by which the frequency of apoptosis in the bursa increases after hatching is unclear, although glucocorticoid concentrations in the embryo increase around the time of hatching (54), and injection of glucocorticoids into the hatched chick induces bursal cell death (55).…”

Glucocorticoids, thyroid hormones, and iodothyronine deiodinases in embryonic saltwater crocodiles

“…In cultured fetal mouse liver cells, the addition of hydrocortisone induced type I ORD activity (32). In the embryonic chicken, endogenous corticosterone levels have been observed to rise late in development (34), around which time there is also an increase in the conversion of T 4 to T 3 (8). Administration of glucocorticoids [dexamethasone (Dex) or corticosterone] or ACTH to embryonic chickens increased plasma T 3 , decreased rT 3 concentrations, and decreased, or did not alter, plasma T 4 concentrations (4, 9).…”