INVESTIGADORES
CYMERYNG Cora Beatriz
artículos
Título:
Site of action of proteinases in the activation of steroidogenesis in rat adrenal gland
Autor/es:
MELE, PG; DADA, LA; PAZ, C; CYMERYNG, CORA BEATRIZ; CORNEJO MACIEL, F; NEUMAN, I; FINKIELSTEIN, C; MENDEZ, C; PODESTÁ, EJ
Revista:
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 1996 vol. 1310 p. 260 - 268
ISSN:
0167-4889
Resumen:
We have
investigated the effect of the proteinase inhibitors 1,10-phenantroline (OP)
and phenylmethylsulfonyl fluoride (PMSF) on steroidogenesis in rat adrenal
cortex. Both PMSF and OP inhibited adrenocorticotropin (ACTH)- and 8-Br
cAMP-induced stimulation of corticosterone synthesis. On the contrary,
arachidonic acid-induced stimulation of corticosterone synthesis was only
slightly inhibited by PMSF and unchanged by OP. Intra- and extracellular cAMP
levels were determined by radioimmunoassay. While PMSF did not affect neither
the intra- nor the extracellular cAMP levels, OP decreased the intra- and extracellular
levels of unstimulated as well as ACTH-stimulated cells. The site of action of
the proteinase inhibitors was also studied by recombination of mitochondria
with the different subcellular fractions in vitro. Addition of PMSF abolished
the stimulation achieved by in vitro activation of cytosol by cAMP and PKA. On
the other hand, OP completely inhibited the activation of mitochondria. Our
results provide evidence for the involvement of proteinases in ACTH-induced
stimulation of steroidogenesis in adrenal cortex both prior to the release of
arachidonic acid and at the level of cholesterol transport from the outer to
the inner mitochondrial membrane.