Effect of isoflurane on expression of p-GSK-3β and β-catenin in neural stem cells in hippocampus of developing rats

Abstract

Objective To evaluate the effect of isoflurane on the expression of phosphorylated glycogen synthase kinase-3 beta(p-GSK-3β)and β-catenin in neural stem cells(NSCs)in the hippocampus of developing rats. Methods Twenty-four 7-day-old Sprague-Dawley rats, weighing 15-20 g, were divided into 2 groups(n=12 each)using a random number table: control group(group C)and 2% isoflurane group(group I). Group C inhaled 30% oxygen for 4 h. Group I inhaled 2% isoflurane in 30% oxygen for 4 h. Six rats were randomly selected from each group, and 5-bromodeoxyuridine(BrdU)200 mg/kg was intraperitoneally injected immediately before anesthesia to assess the proliferation of NSCs in the hippocampal dentate gyrus.The rats were sacrificed at 6 h after the end of anesthesia, and hippocampi were isolated for determination of the number of BrdU positive cells in the dentate gyrus(by immunohistochemistry)and expression of p-GSK-3β and β-catenin in hippocampal tissues(by Western blot analysis). Results Compared with group C, the number of BrdU positive cells was significantly decreased, and the expression of p-GSK-3β and β-catenin was down-regulated in group I(P<0.05). Conclusion Isoflurane can inhibit the proliferation of NSCs in the hippocampal dentate gyrus of developing rats, and the mechanism may be related to down-regulation of the expression of p-GSK-3β and β-catenin. Key words: Isoflurane; Infant, newborn; Hippocampus; Stem cells; Cell proliferation