Continuous real-time measurement of extracellular ascorbate release in the rat striatum in vivo during forebrain ischemia-reperfusion.
Apart from its physiological role as a major antioxidant, ascorbate is highly concentrated in neuropils and ascorbate-mediated protection from excitotoxins has been demonstrated in vitro. Therefore, extracellular release of ascorbate during the early stage of ischemia-reperfusion was measured using a microdialysis electrode technique. One or two probes of the microdialysis biosensor were inserted into the rat striatum. One probe (n=16) was perfused with phosphate-buffered saline (PBS) for continuous oxidative signal recording. A second electropolymerised probe inserted into the other side of the striatum was perfused with PBS containing ascorbate oxidase in six rats. Forebrain ischemia-reperfusion was performed for 10min, followed by reperfusion for 60min. Ascorbate increased transiently during ischemia, and markedly to a maximum of 247.5+/-55. 8 microM from the baseline of 68.5+/-25.3 microM after reperfusion. The marked increase of extracellular ascorbate may be a marker of the early stage of reperfusion.
Yusa
T
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Department of Anesthesiology, University of the Ryukyus, Faculty of Medicine 207 Uehara, Nishihara-cho, Nakagami-gun, 903-0215, Okinawa, Japan. t1935y@med.u-ryuku.ac.jp
D000818:Animals; D001205:Ascorbic Acid / Q000032:analysis / Q000378:metabolism*; D002545:Brain Ischemia / Q000378:metabolism* / Q000503:physiopathology; D003342:Corpus Striatum / Q000737:chemistry / Q000378:metabolism*; D004563:Electrochemistry; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D017551:Microdialysis; D016548:Prosencephalon / Q000737:chemistry / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000378:metabolism* / Q000503:physiopathology; D012815:Signal Processing, Computer-Assisted; D013238:Stereotaxic Techniques
D001205:Ascorbic Acid