title: Plasma antioxidant consumption associated with ischemia/reperfusion during carotid endarterectomy.
abstract: OBJECTIVE
  Thirteen patients undergoing carotid endarterectomy were studied to correlate changes in jugular bulb venous oxygen saturation (SjO2) with indices of free radical production during cerebral ischemia/reperfusion. Levels of oxidant species were also monitored in arterial samples to determine any change across the cerebral circulation.
  
  
  METHODS
  Blood was sampled from a venous catheter inserted in the ipsilateral jugular bulb and from an arterial catheter. Co-oximetry measurements were made to determine jugular bulb venous oxygenation saturation. To monitor changes in oxidant stress, a colorimetric assay was used to determine plasma antioxidant potential, and electron paramagnetic resonance spectroscopy was used to quantify free radical-spin trap adducts formed in a blood sample treated with the spin trap alpha-tert-butyl phenyl nitrone (PBN).
  
  
  RESULTS
  SjO2 decreased significantly from 68 +/- 11% to 61 +/- 10% (P < .05) during clamping of the internal carotid artery and returned to baseline (65 +/- 11%) when the carotid clamp was removed. Jugular venous plasma antioxidant potential decreased significantly from 32.76 +/- 5.42% inhibition to 28.02 +/- 6.77% inhibition (P < .05). There was no concomitant change in arterial plasma antioxidant potential values, indicating a decrease in antioxidant capacity across the cerebral circulation. However, analysis of spin trap-free radical adducts did not provide conclusive evidence for free radical production.
  
  
  CONCLUSIONS
  These results provide supportive evidence for oxidant production during cerebral ischemia/reperfusion in a clinical setting.
authors.affiliation: University Department of Anesthesia, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: P J
authors.initials: PJ
authors.lastname: Bacon
authors.forename: S A
authors.initials: SA
authors.lastname: Love
authors.forename: A K
authors.initials: AK
authors.lastname: Gupta
authors.forename: P J
authors.initials: PJ
authors.lastname: Kirkpatrick
authors.forename: D K
authors.initials: DK
authors.lastname: Menon
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000378:metabolism*; D002545:Brain Ischemia / Q000097:blood*; D002339:Carotid Arteries / Q000601:surgery; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D007601:Jugular Veins; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D010100:Oxygen / Q000097:blood; D017382:Reactive Oxygen Species / Q000378:metabolism; D015424:Reperfusion
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D010100:Oxygen