INVESTIGADORES
VATTA Marcelo Sergio
artículos
Título:
Atrial Natriuretic Factor Stimulates Efflux of cAMP in Rat Exocrine
Autor/es:
RODRIGUEZ M; DIEZ F; VENTIMIGLIA M; MORALES VP; COPSEL S; VATTA MS; DAVIO CA; BIANCIOTTI LG
Revista:
GASTROENTEROLOGY
Editorial:
W B SAUNDERS CO-ELSEVIER INC
Referencias:
Lugar: BETHESDA; Año: 2011 vol. 140 p. 1292 - 1302
ISSN:
0016-5085
Resumen:
BACKGROUND & AIMS: Atrial natriuretic factor
(ANF) prevents increases in intracellular levels of cAMP
that are induced by secretin in the exocrine pancreas. We
investigated the contribution of cyclic adenosine monophosphate
(cAMP) efflux to ANF inhibition of secretin
signaling. METHODS: Intracellular and extracellular
cAMP were measured by radio-binding assays in isolated
pancreatic acini exposed to secretin and other secretagogues,
alone or with ANF. Levels of messenger RNA for
multidrug resistanceassociated protein (MRP)4, MRP5,
and MRP8 were measured by real-time polymerase chain
reaction. MRP4 was knocked down in AR42J cells by
small interfering RNA. In vivo studies were performed in
rats. RESULTS: Pancreatic secretagogues increased levels
of intracellular cAMP, but only secretin and vasoactive
intestinal peptide promoted cAMP efflux; efflux was increased
by ANF, through signaling via natriuretic peptide
receptor-C and phospholipase Cprotein kinase C. In
time-course studies with active phosphodiesterases, levels
of intracellular and extracellular cAMP increased earlier
after the addition of secretin and ANF (1 min) than after
the addition of secretin alone (3 min). Similar kinetic
patterns occurred with a phosphodiesterase inhibitor. A
probenecid-sensitive transporter mediated cAMP egression.
The main cAMP transporter, MRP4, was expressed
in AR42J cells and pancreas. cAMP egression occurred in
AR42J cells exposed to secretin, but this response was
reduced in cells that expressed MRP4 small interfering
RNA. In rats, levels of cAMP in plasma and pancreatic
juice increased after infusion with secretin alone or secretin
plus ANF. CONCLUSIONS: ANF signals via
natriuretic peptide receptor-C coupled to the phospholipase
Cprotein kinase C pathway to increase
secretin-induced efflux of cAMP, probably through
MPR-4. Cyclic AMP extrusion might be a mechanism,
in addition to phosphodiesterase action, to regulate
intracellular cAMP levels in pancreatic acinar cells.Atrial natriuretic factor
(ANF) prevents increases in intracellular levels of cAMP
that are induced by secretin in the exocrine pancreas. We
investigated the contribution of cyclic adenosine monophosphate
(cAMP) efflux to ANF inhibition of secretin
signaling. METHODS: Intracellular and extracellular
cAMP were measured by radio-binding assays in isolated
pancreatic acini exposed to secretin and other secretagogues,
alone or with ANF. Levels of messenger RNA for
multidrug resistanceassociated protein (MRP)4, MRP5,
and MRP8 were measured by real-time polymerase chain
reaction. MRP4 was knocked down in AR42J cells by
small interfering RNA. In vivo studies were performed in
rats. RESULTS: Pancreatic secretagogues increased levels
of intracellular cAMP, but only secretin and vasoactive
intestinal peptide promoted cAMP efflux; efflux was increased
by ANF, through signaling via natriuretic peptide
receptor-C and phospholipase Cprotein kinase C. In
time-course studies with active phosphodiesterases, levels
of intracellular and extracellular cAMP increased earlier
after the addition of secretin and ANF (1 min) than after
the addition of secretin alone (3 min). Similar kinetic
patterns occurred with a phosphodiesterase inhibitor. A
probenecid-sensitive transporter mediated cAMP egression.
The main cAMP transporter, MRP4, was expressed
in AR42J cells and pancreas. cAMP egression occurred in
AR42J cells exposed to secretin, but this response was
reduced in cells that expressed MRP4 small interfering
RNA. In rats, levels of cAMP in plasma and pancreatic
juice increased after infusion with secretin alone or secretin
plus ANF. CONCLUSIONS: ANF signals via
natriuretic peptide receptor-C coupled to the phospholipase
Cprotein kinase C pathway to increase
secretin-induced efflux of cAMP, probably through
MPR-4. Cyclic AMP extrusion might be a mechanism,
in addition to phosphodiesterase action, to regulate
intracellular cAMP levels in pancreatic acinar cells.METHODS: Intracellular and extracellular
cAMP were measured by radio-binding assays in isolated
pancreatic acini exposed to secretin and other secretagogues,
alone or with ANF. Levels of messenger RNA for
multidrug resistanceassociated protein (MRP)4, MRP5,
and MRP8 were measured by real-time polymerase chain
reaction. MRP4 was knocked down in AR42J cells by
small interfering RNA. In vivo studies were performed in
rats. RESULTS: Pancreatic secretagogues increased levels
of intracellular cAMP, but only secretin and vasoactive
intestinal peptide promoted cAMP efflux; efflux was increased
by ANF, through signaling via natriuretic peptide
receptor-C and phospholipase Cprotein kinase C. In
time-course studies with active phosphodiesterases, levels
of intracellular and extracellular cAMP increased earlier
after the addition of secretin and ANF (1 min) than after
the addition of secretin alone (3 min). Similar kinetic
patterns occurred with a phosphodiesterase inhibitor. A
probenecid-sensitive transporter mediated cAMP egression.
The main cAMP transporter, MRP4, was expressed
in AR42J cells and pancreas. cAMP egression occurred in
AR42J cells exposed to secretin, but this response was
reduced in cells that expressed MRP4 small interfering
RNA. In rats, levels of cAMP in plasma and pancreatic
juice increased after infusion with secretin alone or secretin
plus ANF. CONCLUSIONS: ANF signals via
natriuretic peptide receptor-C coupled to the phospholipase
Cprotein kinase C pathway to increase
secretin-induced efflux of cAMP, probably through
MPR-4. Cyclic AMP extrusion might be a mechanism,
in addition to phosphodiesterase action, to regulate
intracellular cAMP levels in pancreatic acinar cells.RESULTS: Pancreatic secretagogues increased levels
of intracellular cAMP, but only secretin and vasoactive
intestinal peptide promoted cAMP efflux; efflux was increased
by ANF, through signaling via natriuretic peptide
receptor-C and phospholipase Cprotein kinase C. In
time-course studies with active phosphodiesterases, levels
of intracellular and extracellular cAMP increased earlier
after the addition of secretin and ANF (1 min) than after
the addition of secretin alone (3 min). Similar kinetic
patterns occurred with a phosphodiesterase inhibitor. A
probenecid-sensitive transporter mediated cAMP egression.
The main cAMP transporter, MRP4, was expressed
in AR42J cells and pancreas. cAMP egression occurred in
AR42J cells exposed to secretin, but this response was
reduced in cells that expressed MRP4 small interfering
RNA. In rats, levels of cAMP in plasma and pancreatic
juice increased after infusion with secretin alone or secretin
plus ANF. CONCLUSIONS: ANF signals via
natriuretic peptide receptor-C coupled to the phospholipase
Cprotein kinase C pathway to increase
secretin-induced efflux of cAMP, probably through
MPR-4. Cyclic AMP extrusion might be a mechanism,
in addition to phosphodiesterase action, to regulate
intracellular cAMP levels in pancreatic acinar cells.CONCLUSIONS: ANF signals via
natriuretic peptide receptor-C coupled to the phospholipase
Cprotein kinase C pathway to increase
secretin-induced efflux of cAMP, probably through
MPR-4. Cyclic AMP extrusion might be a mechanism,
in addition to phosphodiesterase action, to regulate
intracellular cAMP levels in pancreatic acinar cells.