Assuntos
Humanos , Etanolaminas/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilcolina/metabolismo , Linhagem Celular Tumoral , Metais/metabolismo , Osteossarcoma , Monoéster Fosfórico Hidrolases/isolamento & purificação , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Especificidade por SubstratoRESUMO
Using different models of focal cerebral ischemia, the temporal and spatial rules of metabolism and energy changes in the post-ischemia brain tissue were measured by proton magnetic resonance spectroscopy (1HMRS) to provide valuable information for judging the prognosis of acute focal cerebral ischemia and carrying out effective therapy. Nine healthy Sprague-Dawly rats (both sexes) were randomly divided into two groups: The rats in the group A (n = 4) were occluded with self-thrombus for 1 h; The rats in the group B (n = 5) were occluded with thread-emboli for 1 h. The 1H MRS at 30, 40, 50, 60 min respectively was examined and the metabolic changes of NAA, Cho and Lac in the regions of interest were semiquantitatively analyzed. The spectrum integral calculus area ratio of NAA, Cho, Lac to Pcr + Cr was set as the criterion. The values of NAA.Cho in the regions of interest were declined gradually within 1 h after ischemia, especially, the ratio of Cho/(Pcr + Cr), NAA/(Pcr + Cr) at 60 min had significant difference with that at 50 min (P < 0.05). The ratio of Lac/(Pcr + Cr) began to decrease at 40 min from initial increase of Lac in both A and B groups. MR proton spectrum analysis was a non-invasive, direct and comprehensive tool for the study of cellular metabolism and the status of the biochemical energy in acute ischemia stroke.
Assuntos
Isquemia Encefálica/diagnóstico , Metabolismo Energético , Infarto da Artéria Cerebral Média/diagnóstico , Espectroscopia de Ressonância Magnética , Fosforilcolina/metabolismo , Distribuição Aleatória , Ratos Sprague-DawleyRESUMO
Both Fas and PMA can activate phospholipase D via activation of protein kinase Cbeta in A20 cells. Phospholipase D activity was increased 4 fold in the presence of Fas and 2.5 fold in the presence of PMA. The possible involvement of tyrosine phosphorylation in Fas-induced activation of phospholipase D was investigated. In five minute after Fas cross-linking, there was a prominent increase in tyrosine phosphorylated proteins, and it was completely inhibited by D609, a specific inhibitor of phosphatidylcholine-specific phospholipase C (PC-PLC). A tyrosine kinase inhibitor, genistein, can partially inhibit Fas-induced phospholipase D activation. There were no effects of genistein on Fas-induced activation of PC-PLC and protein kinase C. These results strongly indicate that tyrosine phosphorylation may in part account for the increase in phospholipase D activity by Fas cross-linking and D609 can block not only PC-PLC activity but also tyrosine phosphorylation involved in Fas-induced phospholipase D activation.
Assuntos
Camundongos , Animais , Anticorpos Monoclonais/imunologia , Receptor fas/imunologia , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Linhagem Celular , Reagentes de Ligações Cruzadas , Relação Dose-Resposta Imunológica , Ativação Enzimática , Genisteína/farmacologia , Hidrólise , Linfoma/patologia , Fosfolipases Tipo C/antagonistas & inibidores , Fosfolipase D/metabolismo , Fosforilação , Fosforilcolina/metabolismo , Solubilidade , Tionas/farmacologia , Células Tumorais Cultivadas , Tirosina/metabolismo , Água/químicaRESUMO
Both Fas and PMA can activate phospholipase D via activation of protein kinase Cbeta in A20 cells. Phospholipase D activity was increased 4 fold in the presence of Fas and 2.5 fold in the presence of PMA. The possible involvement of tyrosine phosphorylation in Fas-induced activation of phospholipase D was investigated. In five minute after Fas cross-linking, there was a prominent increase in tyrosine phosphorylated proteins, and it was completely inhibited by D609, a specific inhibitor of phosphatidylcholine-specific phospholipase C (PC-PLC). A tyrosine kinase inhibitor, genistein, can partially inhibit Fas-induced phospholipase D activation. There were no effects of genistein on Fas-induced activation of PC-PLC and protein kinase C. These results strongly indicate that tyrosine phosphorylation may in part account for the increase in phospholipase D activity by Fas cross-linking and D609 can block not only PC-PLC activity but also tyrosine phosphorylation involved in Fas-induced phospholipase D activation.