Transient global cerebral ischemia induced in rats by four-vessel occlusion for 20 min produced a... more Transient global cerebral ischemia induced in rats by four-vessel occlusion for 20 min produced an increase in the immunocontent of glial fibrillary acidic protein and a protein phosphorylation response that was different in the CA1 and dentate gyrus areas of the hippocampus. We studied different times of reperfusion (one, four, seven, 14 and 30 days) and observed that the immunocontent and in vitro rate of phosphorylation of glial fibrillary acidic protein in the CA1 region was significantly increased at all intervals after the ischemic insult, indicating that the astrocytic response was maintained for at least 30 days. After reperfusion for 14 days a significant increase in the ratio "in vitro phosphorylation rate/immunocontent" in the CA1 region was observed when compared to control values, to other intervals and to the dentate gyrus, suggesting a hyperphosphorylation of this intermediate filament protein at this interval. In the dentate gyrus, an area less vulnerable to the insult, labelling and immunocontent of glial fibrillary acidic protein were equally increased from four days of reperfusion and the increase remained significant until 30 days, confirming that neuronal death is not the only determining factor for gliosis to occur. In control sham-operated animals, neither the CA1 region nor the dentate gyrus showed significant increases in labelling or immunocontent. Changes in the phosphorylation of glial fibrillary acidic protein may be essential for the plastic response of astrocytes to neuronal damage, as neurons and astrocytes can act as functional units involved in homeostasis, plasticity and neurotransmission.
... ESTUDO SOBRE OPAPEL DA HSP27 NA TOLERÂNCIA À ISQUEMIA CEREBRAL EM UM MODELO IN VIVO EEM CULTU... more ... ESTUDO SOBRE OPAPEL DA HSP27 NA TOLERÂNCIA À ISQUEMIA CEREBRAL EM UM MODELO IN VIVO EEM CULTURAS ORGANOTÍPICAS DE HIPOCAMPO DE RATOS. LAUREN MARTINS VALENTIM Orientadora CHRISTIANNE GAZZANA SALBEGO Co-orientador ...
In recent years organotypic slice cultures of hippocampal tissue of rats have been widely used to... more In recent years organotypic slice cultures of hippocampal tissue of rats have been widely used to study factors involved in neuronal death. Here we used 2D electrophoresis to study the phosphoprotein profile in such cultures and the effect of oxygen/glucose deprivation on this profile. Cultures were prepared from 7-day-old rats. After 14 days in culture the phosphorylation profile in the cultures, as shown by phospho-protein markers undergoing developmental change, closely resembled the profile of fresh tissue from 23-day-old rats. The results suggest that this model could be a good method to observe the development of the tissue and its response to an ischaemic lesion
Transient global cerebral ischemia induced in rats by four-vessel occlusion for 20 min produced a... more Transient global cerebral ischemia induced in rats by four-vessel occlusion for 20 min produced an increase in the immunocontent of glial fibrillary acidic protein and a protein phosphorylation response that was different in the CA1 and dentate gyrus areas of the hippocampus. We studied different times of reperfusion (one, four, seven, 14 and 30 days) and observed that the immunocontent and in vitro rate of phosphorylation of glial fibrillary acidic protein in the CA1 region was significantly increased at all intervals after the ischemic insult, indicating that the astrocytic response was maintained for at least 30 days. After reperfusion for 14 days a significant increase in the ratio "in vitro phosphorylation rate/immunocontent" in the CA1 region was observed when compared to control values, to other intervals and to the dentate gyrus, suggesting a hyperphosphorylation of this intermediate filament protein at this interval. In the dentate gyrus, an area less vulnerable to the insult, labelling and immunocontent of glial fibrillary acidic protein were equally increased from four days of reperfusion and the increase remained significant until 30 days, confirming that neuronal death is not the only determining factor for gliosis to occur. In control sham-operated animals, neither the CA1 region nor the dentate gyrus showed significant increases in labelling or immunocontent. Changes in the phosphorylation of glial fibrillary acidic protein may be essential for the plastic response of astrocytes to neuronal damage, as neurons and astrocytes can act as functional units involved in homeostasis, plasticity and neurotransmission.
... ESTUDO SOBRE OPAPEL DA HSP27 NA TOLERÂNCIA À ISQUEMIA CEREBRAL EM UM MODELO IN VIVO EEM CULTU... more ... ESTUDO SOBRE OPAPEL DA HSP27 NA TOLERÂNCIA À ISQUEMIA CEREBRAL EM UM MODELO IN VIVO EEM CULTURAS ORGANOTÍPICAS DE HIPOCAMPO DE RATOS. LAUREN MARTINS VALENTIM Orientadora CHRISTIANNE GAZZANA SALBEGO Co-orientador ...
In recent years organotypic slice cultures of hippocampal tissue of rats have been widely used to... more In recent years organotypic slice cultures of hippocampal tissue of rats have been widely used to study factors involved in neuronal death. Here we used 2D electrophoresis to study the phosphoprotein profile in such cultures and the effect of oxygen/glucose deprivation on this profile. Cultures were prepared from 7-day-old rats. After 14 days in culture the phosphorylation profile in the cultures, as shown by phospho-protein markers undergoing developmental change, closely resembled the profile of fresh tissue from 23-day-old rats. The results suggest that this model could be a good method to observe the development of the tissue and its response to an ischaemic lesion
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