The aim of the present study was to develop a perifusion technique for rat adrenal glomerulosa slices as a model to study the kinetics of corticosteroid production in vitro. Perifusion of adrenal tissue with increasing concentration of ACTH (3.16 X 10(-12) to 10(-9) M) led to a dose-related stimulation of corticosterone and aldosterone secretion. Administration of cytochalasin B did not alter the basal secretion of corticosterone and aldosterone. In addition, cytochalasin B did not modify the response of glomerulosa tissue to ACTH. The results indicate that the perifusion model for glomerulosa fragments may provide valuable information, concerning the kinetics of steroid production and its regulation at the cellular level.