Biochemical and morphological changes in rat brain synaptosomes after exposure to normobaric hyperoxia in vivo.
Adult rats were submitted to normobaric hyperoxia for 1 to 24 h, then the brain synaptosomes were isolated and their metabolic and morphologic properties were studied. Hyperoxia lasting 1-2 h significantly increased the content of thiobarbituric acid-reactive material (TBAR) and decreased the level of protein thid groups. During the next 5-8 h of hyperoxia SH groups as well as TBAR content became almost normal, reflecting adaptation of the animals to an elevated oxygen tension. After 24 h of hyperoxia a maximal increase in the TBAR content and parallel fall in protein thiol groups were noted. Simultaneously, significant morphological differences between control synaptosomes and synaptosomes isolated from rats exposed to 24 h oxygenation were observed in electron microscopy. The high-affinity dopamine uptake in hyperoxic synaptosomes was significantly increased in all experimental groups. A specific high sensitivity of the dopamine uptake system in synaptoplasmatic membranes to the free radical modification of the membrane structure is suggested.
Gordon-Majszak
W
W
Polish Academy of Sciences, Department of Neurochemistry, Warsaw.
Gajkowska
B
B
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004298:Dopamine / Q000378:metabolism; D008297:Male; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013570:Synaptic Membranes / Q000378:metabolism; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D013858:Thiobarbiturates
D013438:Sulfhydryl Compounds; D013858:Thiobarbiturates; C029684:thiobarbituric acid; D010100:Oxygen; D004298:Dopamine