Effect of 2-cyclohexene-1-one-induced glutathione diminution on ischemia/reperfusion-induced alterations in the physical state of brain synaptosomal membrane proteins and lipids.
Glutathione is able to protect membrane proteins from oxidative stress. In ischemia/reperfusion injury, free radicals cause synaptosomal membrane protein and lipid oxidation that is prevented by the free radical scavenger N-tert-butyl-alpha-phenylnitrone (Hall N. C. et al. (1995) Neuroscience 64, 81-89; 69, 591-600). We wondered if diminution of glutathione would lead to further membrane alterations. Accordingly, the effects of glutathione depletion, by intraperitoneal administration of 2-cyclohexene-1-one, on the physical state of cortical synaptosomal membrane proteins and lipids, with and without global ischemia/reperfusion, were studied in vivo and in vitro in adult and aged gerbils utilizing electron paramagnetic resonance spectrometry. 2-Cyclohexene-1-one (100 mg/kg, i.p.) was administered 30 min prior to 10-min ischemia followed by 1 or 14 h reperfusion. This glutathione reduction agent was also administered to gerbils under the same temporal schedule in the absence of ischemia and compared to untreated controls. Synaptosomal membranes were labeled with a protein-specific spin label, 2,2,6,6-tetramethyl-4-maleimidopiperidine-1-oxyl, or a lipid-specific spin probe, 5-doxylstearic acid. There were no significant changes in the physical state of the lipid portion of synaptosomal membranes when comparing ischemia reperfusion and 2-cyclohexene-1-one-treated ischemia reperfusion in either the adult or aged gerbils. However, glutathione depletion without ischemia/reperfusion caused significant changes in the physical state of the protein portion of cortical synaptosomal membranes in both the adult and aged models. Glutathione depletion, without ischemia/reperfusion, in the adult model showed a maximum change at 3 h that returned to control values by 14 h. In contrast, the aged model showed significant changes at 1 h reperfusion, which did not return to control values by 14 h reperfusion. Glutathione depletion combined with ischemia/reperfusion caused initial protein change in both adult and aged models at 1 h reperfusion, which did not return toward control values by 14 h reperfusion. The results of this study suggest that glutathione depletion increases the severity of membrane protein damage associated with ischemia/reperfusion injury.
Hall
N C
NC
Department of Chemistry, University of Kentucky, Lexington 40506, USA.
Carney
J M
JM
Plante
O J
OJ
Cheng
M
M
Butterfield
D A
DA
D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy*; D002540:Cerebral Cortex / Q000098:blood supply / Q000737:chemistry; D003512:Cyclohexanones / Q000494:pharmacology*; D005849:Gerbillinae; D005978:Glutathione / Q000378:metabolism*; D050356:Lipid Metabolism; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D015427:Reperfusion Injury / Q000188:drug therapy*; D013113:Spin Labels; D013574:Synaptosomes / Q000737:chemistry / Q000187:drug effects*
D003512:Cyclohexanones; D008565:Membrane Proteins; D013113:Spin Labels; C028215:2-cyclohexen-1-one; D005978:Glutathione