Prostaglandins PGE₂ and PGF_2α in Human Fetal Lung: Immunohistochemistry and Release from Organ Culture

Abstract

Immunobistochemical studies in human fetal lung have shown that epithelial and endothelial cells are both strongly and equally reactive for PGE₂. In contrast, epithelial PGF_2α reactivity varied between fetuses, in some as intense as endothelial staining and in others very much less. As lung organ cultures differentiated, the intensity of PGE₂ staining declined in airways and blood vessels, although it was still weakly positive at 10 days. In contrast, epithelial cells rapidly became negative for PGF_2α, whereas PGF_2α positivity was retained in blood vessels, albeit less obviously. PGF_2α and PGE₂ were released into the media of organ cultures in decreasing amounts as cultures progressed. Amounts of released PGF_2α were greater by 2- to 10-fold than PGE₂. Our findings suggest that the endogenous production of prostaglandins by human fetal lung in organ culture has a key role in the self-differentiation process that occurs in the absence of sera or added growth factors or hormones.