GIRARDI Elena Silvia
congresos y reuniones científicas
Astrocytic S100 expresión is decreased in an experimental epilepsy model
GIRARDI E, RAMOS AJ, SALVAGO A. AND BRUSCO A.
Encuentro; V European Meeting on Glial Cell Function in Health and Disease. Euroglia 2002; 2002
Astrocytic S100b expresión is decreased in an experimental epilepsy model? Girardi E, Ramos AJ, Salvago A. and Brusco A. Instituto de Biología Celular y Neurociencia ?Prof. Dr. E. De Robertis?, Facultad de Medicina, Universidad de Buenos Aires. Argentina 3-mercaptopropionic acid (MP) administration is a well known experimental epilepsy model. We have previously demostrated an astroglial reaction in hippocampus and cerebral cortex after MP administration. In this work we studied the S100eta nuerotrophic factor expression in astroglial cells. S100beta is found diffusely in cytoplasm, is associated with membranes and cytoskeleton constituents and is also secreted by astrocytes. The aim of this work was to study S100beta expression in astrocytes in hippocampus and cerebral cortex after repetitive doses of the convulsant drug MP. These two areas have shown an important astroglial reaction, including GFAP hypertrophic astrocytes with increased soma size, large and tortuous processes. Male Wistar rats (250-300g) were daily administerd with MP (45mg/kg i.p.) during four (MP4) or 7 (MP7) days. Rats injected with saline were used as control. One days after the last injectionrats were deeply anaesthetized with chloral hydrate (300mg/kg) and fixed by perfussion. Brains were dissected and processed for immunohistochemistry using antiS100beta as primary antibody and peroxidase-antiperoxidasetechnique. Computer assisted image analysis was used to quantify the density of S100beta immunoreactivity. Density of S100beta immunoreactivity showed an important decrease in hippocampal CA1 area in MP4 (65%) and MP7 (56%). In cerebralcortex S100beta expressionwas also decreased in both treatmentby 60% and 56% in MP4 and MP7, erspectively. Theobserved astroglial S100beta expression decrease may be due to an increase in the secretion of this diffusible growth factor from astrocytes or to a reduction to S100beta expression in glial cells. These changes in S100beta expression may have critical role in the epilepsy due to its neurotrophic action. Work was supported by UBACYT B033, CONICET and Ministerio de Salud. Argentina