The regulation and role of fetal adrenal development in human pregnancy.
The rapid growth of the human fetal adrenal gland, which is primarily a reflection of the growth of the unique fetal zone, is regulated by ACTH acting indirectly to stimulate the expression of locally produced growth factors, of which IGF-II and bFGF appear to play key roles. Through most of gestation, the outer definitive zone appears to function as a reservoir of progenitor cells which move centripetally to populate the rest of the gland. At the end of pregnancy, the fetal zone undergoes senescence through an apoptotic process. Activin and TGF-beta are capable of inducing apoptosis in the fetal zone. Corticotropin-releasing hormone, which is produced by the placenta in markedly increased amounts at the end of gestation, may orchestrate a variety of processes, including direct stimulation of fetal adrenal steroidogenesis, culminating in the initiation of parturition.
Jaffe
R B
RB
Reproductive Endocrinology Center, University of California, San Francisco 94143-0556, USA.
Mesiano
S
S
Smith
R
R
Coulter
C L
CL
Spencer
S J
SJ
Chakravorty
A
A
D000311:Adrenal Glands / Q000196:embryology*; D003346:Corticotropin-Releasing Hormone / Q000502:physiology; D005314:Embryonic and Fetal Development / Q000502:physiology; D004815:Epidermal Growth Factor / Q000502:physiology; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000502:physiology; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000502:physiology; D011247:Pregnancy; D016211:Transforming Growth Factor alpha / Q000502:physiology
D016211:Transforming Growth Factor alpha; D016222:Fibroblast Growth Factor 2; D004815:Epidermal Growth Factor; D007335:Insulin-Like Growth Factor II; D003346:Corticotropin-Releasing Hormone