Lung maturation and prevention of hyaline membrane disease.

Small pieces of 7 to 12 week old human foetal lung, derived from legal abortions, were maintained in organ culture for 21 days. In the last 5 days of cultivation the explants were treated with dexamethasone (10 ng/ml) or betamethasone (10 ng/ml) or fenoterol (10 ng/ml), or fenoterol + dexamethasone, or bromhexine VIII metabolite (ambroxol: 12 ng/ml) and were then prepared for electronmicroscopic examination. In another experimental group the pregnant were treated before the interruption of 14-17-week old pregnancies with ambroxol (total dose, 1080 mg). The interruption was carried out with PgF2 alpha, and lung pieces were immediately prepared for electron microscopic examination. From the experiments the following conclusions can be drawn: Surfactant production can already be induced in 7-12 week old human fetal pneumocytes; Corticosteroids (dexamethasone, betamethasone) stimulate the formation of osmiophilic lamellar bodies; Fenoterol has probably no effect on the surfactant production. Its administration together with dexamethasone, however, does not inhibit the development of osmiophilic lamellar bodies; Ambroxol has a marked effect on the synthesis of lamellar bodies in vitro: Ambroxol or its active metabolite probably have a reduced placental transport in the first trimester of human pregnancy; Thin-layer chromatography has revealed no qualitative difference between the treated and untreated cultures.