Cortisol in Fetal Fluids and the Fetal Adrenal: RESULTS

Adrenal Cortisol

Adrenal gland pairs from neonates weighed 1.56 ± 0.18 mg (n = 14) on the day of birth. The protein content of fetal and neonatal adrenals increased linearly from Day 24 pregnancy to Day 0 postpartum (Fig. 1a). Cortisol content and concentration in fetal adrenals increased progressively from Day 24 of pregnancy to reach a maximum at term on Day 26 (Fig. 1, b and c). Total cortisol content of fetal adrenal pairs increased significantly (t-test, p < 0.01), from 12.3 ± 11.9 pg on Day 24 to 133.4 ± 83.9 pg by Day 26. Cortisol concentration, expressed per milligram of protein, also increased significantly (t-test, p < 0.05), from 2.7 ± 2.7 ng/mg (n = 6) on Day 24 to 11.5 ± 13.0 ng/mg on Day 26. Within 24 h postpartum, cortisol content and concentration in fetal adrenals had decreased significantly (t-test), falling to 20.1 ± 11.6 pg (p < 0.01) and 1.7 ± 1.4 ng/mg (p < 0.01), respectively. ventolin 100 mcg

Adrenal Production

Basal production of cortisol by fetal adrenals in vitro was 16.4 ± 10.2 ng/adrenal per 24 h. Stimulation of adrenal glands with either ACTH or PGE2 (Fig. 2) resulted in significant increases in cortisol production (paired t-test; ACTH: p < 0.001; PGE2: p < 0.05).

Fetal Fluid Cortisol

The cortisol concentration of YSF, allantoic fluid, and fetal plasma (Fig. 3) increased progressively from Day 24 pregnancy to reach a maximum at term on Day 26. In all fetal fluids, cortisol levels were significantly elevated on Day 26 compared with Day 24 values (t-test, all p < 0.01). Within 24 h postpartum, mean plasma cortisol was half the mean Day 26 gestation levels although this decrease was not significant (p > 0.05).
Fig1Cortisol in Fetal Fluids
FIG. 1. a) Protein content, b) total cortisol content, and c) cortisol concentration of fetal and neonatal adrenals over the last 3 days of pregnancy and within 24 h postpartrum (PP). Protein content increased linearly (r = 1.00, m = 2.71). Numbers in parentheses indicate sample size, and error bars are SEM.

Fig2Cortisol in Fetal Fluids
FIG. 2. Cortisol production by fetal adrenals in vitro after 24-h tissue culture. Treatment with a) ACTH and b) PGE2 significantly increased basal cortisol production (paired t-test, both p < 0.05). Numbers in parentheses indicate sample size, and error bars are SEM.

Fig3Cortisol in Fetal Fluids
FIG. 3. Cortisol concentrations in a) YSF and b) allantoic fluid over the last 3 days of pregnancy and c) fetal/neonatal plasma within 24 h postpartum (PP). Numbers in parentheses indicate sample size, and error bars are SEM.

This entry was posted in Adrenal and tagged Adrenal, Cortisol, Fetal Fluids, Parturition.