Ontogenetic expression of estrogen and progesterone receptors in the mouse lung

In the mammalian lung, estrogen and progesterone seem to be import for the morphological and functional maturation. Despite this, only sparse information is available on the onset and ontogenic expression of estrogen receptors (ER) and progesterone receptors (PR) in the perinatal lung. The expression patterns of the two known nuclear isoforms ER-alpha and ER-beta and the PR were analyzed in the pre- and postnatal lungs of BALB/c mice. Steroid receptor mRNA expression of all three receptors were highest in the prenatal lung and declined thereafter to significantly lower levels in the postnatal and adult lung. The ontogenetic pattern of ER and PR expression supports the view that both gonadal steroids are pivotal for prenatal lung maturation and development.