Feto-neonatal hormonology in premature delivery

A postulated role for 16α-hydroxydehydroepiandrosterone in the prevention of respiratory distress syndrome

The concentrations of 16-hydroxylated steroids, especially 16 alpha-hydroxydehydroepiandrosterone (16 alpha-hydroxyDHEA) in amniotic fluid and infants' blood are elevated many fold at normal birth time as compared with mid-term concentrations and those found in prematurely born infants. It is logical to postulate that 16 alpha-hydroxyDHEA may be the natural inducer of lung maturation and preventor of respiratory distress syndrome. Because the infant born at normal gestational terminus has a very high concentration of blood 16 alpha-hydroxyDHEA, treating premature infants with amounts of this steroid to provide blood concentrations that are normal in full-term infants should be a well-tolerated procedure and should avoid the developmental problems associated with glucocorticoid treatments.

C19‐5‐ene Steroids in Nature

Dehydroepiandrosterone (DHEA), produced from cholesterol in the adrenals, is the most abundant steroid in our circulation. It is present almost entirely as the sulfate ester, but the free steroid is the form that serves as a precursor of estrogens and androgens, as well as 7- and 16-oxygenated derivatives. Mammalian tissues reduce the 17-keto Group of DHEA to produce androstenediol-a weak estrogen and full-fledged androgen. Its androgen activity is not inhibited by the anti-androgens commonly used to treat prostate cancer. It is probably responsible for the growth of therapy-resistant prostate cancer. DHEA is hydroxylated at the 7 alpha position, and this derivative is oxidized by 11 beta-hydroxysteroid dehydrogenase to form 7-keto DHEA. The latter is reduced by the same dehydrogenase to form 7 beta-hydroxy DHEA. When fed to rats, each of the latter three steroids induce the formation of two thermogenic enzymes in the liver. The late-term human fetus produces relatively large amounts of 16 alphahydroxy DHEA, which serves the mother as a precursor of estriol.

Plasma and adrenal corticosterone concentrations and liver glycogen content in premature mice at birth and during neonatal development

The concentrations of corticosterone in the plasma and adrenal glands and the content of glycogen in the liver were estimated from birth to day 6 after birth in surviving premature mice removed by Caesarean section on day 19 of pregnancy and submitted to reanimation during 30 min; the neonates were nourished by nursing mothers from 30 min after birth. A group of full-term newborns was removed by Caesarean section on day 20 of pregnancy and killed 30 min after reanimation. Premature mice were characterized by neonatal changes of three parameters used. The plasma corticosterone level reached a peak in the first 6 h after birth, then decreased until day 6. The adrenal corticosterone level did not vary significantly 30 min after birth, then decreased progressively until day 2. The liver glycogen content, very high on day 19 of pregnancy, increased 30 min after birth, then fell sharply until day 2. In full-term newborns removed by Caesarean section and killed 30 min after reanimation the plasma corticosterone level increased, whereas the adrenal corticosterone level and the liver glycogen content did not decrease. The adrenal gland of surviving premature mice was able to respond to the stress induced by the reanimation; the stimulation of glucocorticoid function was similar in both neonates.