In vitro behavior of human fetal lung maintained in organ culture. Light and electron microscopic studies.

Human fetal lung obtained from 9-26 = weeks = old embryos were maintained in organ culture for 2-5 weeks. The in vitro survival and changes are clearly age dependent. The best survival was obtained with lung tissue from the early glandular period. With these young embryos tubular dilation was frequent during the 1st week. The relatively short duration of culture permitted only a fragmentary study of differentiation of the human lung in vitro but, with the exception of tubular dilations, most of the in vitro changes were also found during lung differentiation in vivo = monostratification of epithelium, bronchiolar development, decrease of glycogen, appearance of myelinlike figures, fibroblastic and myoblastic transformation of mesenchymal cells.