RESPONSE TO ACTH AND DIBUTYRYL CYCLIC-AMP BY ENUCLEATED ADRENOCORTICAL TUMOR-CELLS

Y-1-L cells, a subline of the Y-1 functional mouse adrenocortical tumor cell line, were enucleated with cytochalasin B and the response of these enucleated cells to ACTH and dibutyryl cyclic AMP (dbcAMP) was examined. Enucleated Y-1-L cells maintained a basal steroid output for at least 24 h and responded to ACTH (10 mU/ml) or dbcAMP (1 mM) by a change from flat to rounded cell shape, and increased steroidogenesis. The steroidogenic response of enucleated cells during the first 3 h after enucleation was highly significant and, though it decreased rapidly thereafter, it persisted to a limited degree for up to 12 h. The morphologic change could be induced even at 33 h after enucleation. The nucleus is not required for the expression of the acute effects of ACTH or dbcAMP and the cytoplasmic components necessary for cell rounding and a steroidogenic response are stable for 36 and 12 h, respectively.