Study of the ductal epithelial cell component of human labial salivary glands in vitro.

Salivary gland cultures were propagated from primary explant cultures of 55 human labial gland biopsies. Cultures were maintained for at least 7 days in 199 medium plus 20% newborn calf serum and growth measured at this time both by cell counting and planimetry of the area. Ductal cell population identification was undertaken on the basis of an intra-cellular function, the latter being the histochemical detection of the enzyme 11 beta-hydroxysteroid dehydrogenase. Epithelioid cell lines were derived by enzymatic and mechanical means. Non-invasive quantitation of the proportion of ductal epithelial cells present in primary explant cultures, and derived cell lines, was attempted using a radioimmunoassay to detect conversion in the media of cortisol to cortisone. The cell lines were terminated after undergoing 18 passages over 20 weeks. By this time the epithelioid morphology of cells could no longer be equated to a differentiated epithelial cell origin since conversion of cortisol to cortisone in the growth media no longer occurred.