Effects of intermittent high glucose on apoptosis and PTEN expression in islet cells / 中国病理生理杂志

ABSTRACT

[ ABSTRACT] AIM:To investigate whether the increase in PTEN expression is related to apoptosis, and whether it is regulated by reactive oxygen species( ROS) .METHODS: The rat islet cells were divided into constant low glucose group ( group L) , constant high glucose group ( group H) , glucose fluctuation group ( group F) , low glucose after high glucose group (group HL) and low glucose after fluctuation group (group FL).The ROS level, apoptotic rate, intracellu-lar calcium, insulin release and PTEN protein expression were analyzed.RESULTS:Compared with groups H and L, the insulin secretion decreased, and intracellular calcium, ROS level, PTEN protein expression and apoptotic rate increased in group F ( P<0.05) .Compared with group H, the intracellular calcium, ROS level, PTEN protein expression and apoptot-ic rate in group HL decreased, but were still higher than those in group L (P<0.05).Compared with group F, the intra-cellular calcium, ROS level, PTEN protein expression and apoptotic rate in group FL decreased, but were still higher than those in group L (P<0.05).CONCLUSION:Glucose fluctuation can cause the apoptosis of islet cells more easily than constant high glucose.This may be related to the change of intracellular calcium and increase in oxidative stress which pro-motes PTEN expression.The recovery of glucose level to some extent relieves oxidative stress, decrease PTEN expression and reduce cell damage.