Glucocorticoid receptors in developing rat brain and liver

Area of Science:

• Endocrinology
• Developmental Biology
• Neuroscience

Background:

• Glucocorticoids are crucial for fetal development and postnatal adaptation.
• Dexamethasone receptors mediate glucocorticoid effects.
• Understanding receptor development is key to comprehending tissue maturation.

Purpose of the Study:

• To characterize the developmental profile of dexamethasone receptors in rat liver and brain cytosol.
• To investigate the maturation of glucocorticoid receptor binding and nuclear translocation in vivo and in vitro.

Main Methods:

• Conventional equilibrium steroid binding assays were used to measure receptor levels.
• Adrenalectomized and intact rats were studied during prenatal and postnatal development.
• DEAE-Sephadex A50 chromatography and in vitro/in vivo nuclear binding assays were performed.

Main Results:

• Receptor binding was detectable by day 17 of gestation in both tissues.
• Cytosolic receptor levels reached adult values by postnatal day 1 in intact animals.
• Nuclear binding capacity matured postnatally, with adult levels observed by the end of the first week in vivo.

Conclusions:

• Dexamethasone receptors are present early in development and mature rapidly after birth.
• Both cytosolic and nuclear components of the glucocorticoid receptor system are functional during the early postnatal period.
• These findings highlight the critical role of glucocorticoids in perinatal development.