Human bronchial explants in long-term culture: establishing a baseline for secretion.

A serum-free culture medium was employed to evaluate both qualitative and quantitative aspects of secreted proteins derived from human bronchial explants over a period of 26 to 50 d. It was found that protein and hexose were secreted at a reasonably constant rate during this period. Viability of explants was assessed by histological examination, attachment to scored grids of the petri dish, incorporation of labeled precursors into tissue proteins, and by fluorographic analysis of the sodium dodecyl sulfate-polyacrylamide gel pattern of the secreted material. This culture system is useful as a model for the study of secretory products and processes and how they are affected by various stimuli.