Research On Effect Of Single Intranasal Insulin Delivery On Propofol Induced Tau Hyperphosphorylation

Objective:To investigate the impact of single intranasal insulin delivery on propofol-induced tau hyperphosphorylation.Methods:SD rats (8weeks old, male) were treated with intranasal insulin or0.9%saline30minutes before intraperitoneal (i.p.) injection of propofol or equivalent amount of vehicle, and were sacrificed by decapitation1h following i.p., The hippocampi were collected and analyzed by Western blot developed with antibodies against phosph-tau (Thr205), GSK-3β, phosph-GSK-3β(Ser9), AKT, phosph-AKT (Ser473), ERK, phosph-ERK and PP2A-C.Results:Propofol induced a dramatic hyperphosphorylation of tau, which was approved to be resulted from the decrease of PP2A rather than the activation of tau kinases. Single intranasal insulin delivery did not prevent the changes induced by propofol.Conclusions:Single intranasal insulin delivery can not prevent the hyperphosphorylation of tau at Thr205induced by propofol. Further studies are still needed to confirm the protective role of insulin on anesthesia-induced hyperphosphorylation of tau.