RESUMO
Objective To investigate the effect of splenectomy on tau expression in rat hippocampus.Methods One hundred and five male SD rats aged 6 months weighing 350-400 g were randomly divided into 3 groups: group A control (n = 15); group B anesthesia (n =45) and group C surgery (n =45). The animals were anesthetized, intubated and mechanically ventilated. In group B and C the animals were anesthetized with 1.5% isoflurane for 2 h. In group C splenectomy was performed. The animals were killed on the 1st, 3rd and 7th day after anesthesia and surgery. The hippocampi were immediately removed for determination of IL-1 and TNF-α mRNA and protein expression, expression of total tau, phosphorylated tau at Thr-205 and Ser-396 and activity of glycogen synthase kinase-3 beta (GSK-3β). Results There was no significant difference in the expression of phosphorylated tau at Thr-205 and Ser-396 between control and anesthesia groups. Surgery significantly increased the expression of IL-1β and TNF-α and induced rapid and massive hyperphosphorylation of tau at Thr-205 and Ser-396 epitope in the hippocampus and activation of GSK-3β. Conclusion Surgical trauma induces inflammatory response in hippocampus, activates GSK-3β and increases phosphorylation of tau.