FREE-RADICAL SCAVENGER DEPLETION IN POSTISCHEMIC REPERFUSION BRAIN-DAMAGE

In the present study the influence of pretreatment with various GSH de pletors such as buthionine sulfoximine (BSO) and diethylmaleate (DEM) was investigated in rats following cerebral postischemic reperfusion. Moreover, the effect of diethyldithiocarbamic acid (DDC), inhibitor of endogenous Cu,Zn-SOD, was evaluated. A significant depletion (40% of control value) of GSH levels was observed 24 h after DEM administratio n; after 48 h the value reached control levels. BSO showed maximal GSH depletion (59%) 24 h after administration and it was constant for alm ost 48 h. DDC administration caused a marked decrease (60%) of Cu,Zn-S OD activity 4 h after the injection and induced a marked decrease in p ercentage of survival with respect to control (untreated, ischemic) ra ts, when administered 4 h before ischemia. BSO and DEM prolonged the s urvival time of animals when administered 24 h before ischemia. This l ast paradoxical effect is unclear at present, but it might be due to a n influence on glutamate cascade.