Fetal Rat Adrenal Growth and Steroidogenesis <i>in vitro </i>after Maternal Dexamethasone Treatment

Abstract

Two groups of female rats were treated with dexamethasone phosphate (DEX) for 24 h. One group received DEX in drinking water (10 μg/ml) on the 15th day of pregnancy (DEX_15–16), and the second group on the 17th day of pregnancy (DEX_17–18). The mothers and fetuses were sacrificed on the 20th and 22nd days of pregnancy. DEX reduced adrenal weights and concentration of corticosterone in plasma of the treated females and their fetuses. Fetal body weight was also reduced. However, the lightest adrenal glands were found in fetuses of the DEX_17–18 mothers. Furthermore, the 19-day-old fetuses belonging to the DEX_17–18 mothers had smallest amounts of corticosterone in plasma, and in plasma, and their adrenal glands produced the lowest amounts of radioactive corticosterone, 11-deoxycorticosterone and 18-hydroxy-ll-deoxycorticosterone from 4-¹⁴C progesterone after 1 h of incubation in vitro. In the 21-day-old fetuses belonging to both the groups of treated mothers, the production of steroids by the adrenal glands was similar and to the same extent reduced in comparison to the control fetuses.

Disproportionate Growth of Organs and Body Weight following Glucocorticoid Treatment of the Rat Fetus

“…Other studies with dexamethasone treatment in fetal rats and guinea pigs have shown that fetal adrenal suppression is related to the dose, stage of gestation and duration of recovery period [34,36,48]. Fetal rhesus mon keys exposed to maternal betamethasone doses comparable to those used in human pregnancy have variously shown either lack of suppression [39] or suppression [29,30] of adrenal weight.…”

Suppression of adernal cortical growth and differentiation in fetal rats exposed to dexamethasone

“…Fetal adrenal growth is also inhibited by high levels of circulating maternal corticosteroids which can cross the placenta and block fetal pituitary stimulation of the adrenals (Zarrow et al, 1970;D'Angelo et al, 1973;Milkovic and Domac, 1973;Klepac and Milkovic, 1979).…”