M. Feuilloley et al., EFFECTS OF SELECTIVE DISRUPTION OF CYTOSKELETAL ELEMENTS ON STEROID-SECRETION BY HUMAN ADRENOCORTICAL SLICES, The American journal of physiology, 266(2), 1994, pp. 50000202-50000210
The role of the cytoskeleton in corticosteroid secretion in normal hum
an adrenal gland was investigated in vitro, using the perifusion techn
ique and confocal laser scanning microscopy. Vinblastine, which select
ively disrupted microtubules in adrenocortical cells, did not modify t
he basal release of cortisol but induced a 58% inhibition of the respo
nse to adrenocorticotropic hormone (ACTH). In contrast, vinblastine di
d not alter dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP)-in
duced steroid secretion. Cytochalasin B treatment caused disappearance
of microfilaments and blocked the stimulatory action of ACTH and DBcA
MP on cortisol secretion. beta,beta'-Iminodipropionitrile disorganized
the cytokeratin intermediate filaments but did not alter spontaneous
and ACTH-evoked cortisol release. These results, which provide the fir
st evidence for an action of cytoskeleton inhibitors on cortisol relea
se from normal human adrenocortical cells, show that microtubules are
involved in the mechanism of action of ACTH at a step preceding adenos
ine 3',5'-cyclic monophosphate formation, whereas microfilaments are i
nvolved in a late and common step of adrenal steroidogenesis.