Hydrocortisone is associated with cell surface blebbing in cultures of human embryonic lung fibroblasts

Treatment with hydrocortisone (HC) is associated with increased cell surface blebbing of proliferatively active WI-38 and IMR-90 fibroblasts at low and high population doubling levels within the first 24 h after seeding. Time course studies show a marked decrease in blebbing after 2 days. In contrast, very old cells near the end of the population life span (greater than 96% life span completed) show blebbing which is independent of HC treatment. Since the time of increased HC-associated blebbing in cycling cell populations coincides with the time during which HC-treated cells condition the medium with a growth-stimulating (autocrine) factor, it is possible that blebbing may represent extrusion of this factor from the cells at these times.