Abstract
Summary Chromaffin cells in organotypic cultures of adrenal glands from 19 day rat embryos developed a marked increase in the volume of their rough endoplasmic reticulum (RER) and enlargement of nucleoli in response to 1 mM dibutyryl cyclic AMP (dbcAMP) treatment for 17 daysin vitro. 0.1 mM dbcAMP had a similar but less dramatic effect. When dbcAMP was removed from the medium after 11 daysin vitro, cells became more like control explants treated with no additives, suggesting the effects of dbcAMP were reversible. ACTH which selectively stimulates adrenal cortical cells had no effect on RER morphology of chromaffin cells. The ‘neuronal-like’ configuration of dbcAMP treated chromaffin cells is discussed.