INVESTIGADORES
CAPANI Francisco
congresos y reuniones científicas
Título:
ASTROCYTIC HYPERTROPHYC RESPONSE INDUCED BY EARLY LEAD EXPOSURE MODIFIED AFTER GLUCOCORTICOID TREATMENT.
Autor/es:
CAPANI, F. ; LOIDL, C. F. ; CEBRAL, E. ; L¡ÜPEZ-COSTA, J. J. ; SELVIN-TESTA, A.
Lugar:
Orlando
Reunión:
Congreso; Society for Neuroscience Meeting; 2002
Resumen:
Delayed effects
induced in hippocampal and cerebral cortex astrocytes after lead
exposure (PbE) and their modifications after glucocorticoid treatment
were studied in rats at 45, 60, 90 and 120 postnatal days (PN). Study
was done to determine changes in astrocytes after PbE [1g% lead acetate
in drinking water prior to mating and continued after weaning until 120
PN and glucocorticoid (Gluc) treatment after 60 PN administered via
injection 50mg/kg/day in corn oil vehicle, for 3 weeks, monday to
friday]. Animals were killed at the next day after the end of treatment,
and in the next 7, 14 and 28 days. To study astroglia changes we used
immunohistochemistry for gliofibrillar acidic protein (GFAP), vimentin
(VIM) combined with transmission electron microscopy. At 60 PN astrocyte
hypertrophy was revealed by GFAP and VIM. At the end of Gluc treatment
hyperactive behavior changed by depression, and large decrease in the
GFAP and VIM expression near control levels, despite the high blood
lead-levels, were observed in hippocampus and cortex. At the same time,
no neuronal alteration were seen. Also, Gluc administration
down-regulated the concentration of GFAP, in control rats. Gluc affects
regional reactivity induced by the lead without overt citotoxicity, and
modifies the synthesis of GFAP through a mechanism distinct from that
operating in injury tissue. Gluc (an important regulator of
physiological and behavioral responses) inhibits GFAP expression and
reduces astroglial reactivity, may alter neuronal milieu indirectly by
affecting astrocytes.