Dexmedetomidine acts as an oxidative damage prophylactic in rats exposed to ionizing radiation.

STUDY OBJECTIVE: To investigate the effects of dexmedetomidine on oxidative injury caused by ionizing radiation. DESIGN: Randomized controlled experimental study. SETTING: Department of radiation oncology and research laboratory of an academic hospital. INTERVENTIONS: Twenty-eight rats were randomized to 4 groups (n=7 per group). Group S rats were administered physiologic serum; group SR rats were administered physiologic serum and 10 Gy external ionizing radiation. Groups D100 and D200 were administered 100 and 200 µg/kg dexmedetomidine intraperitoneally, respectively, 45 minutes before ionizing radiation. MEASUREMENTS: Liver, kidney, lung, and thyroid tissue and serum levels of antioxidant enzymes (glutathione peroxidase [GPX], superoxide dismutase, and catalase) and oxidative metabolites (advanced oxidation protein products, malondialdehyde, and nitrate/nitrite, and serum ischemia-modified albumin) were measured 6 hours postprocedure. MAIN RESULTS: In group SR, IR decreased antioxidant enzyme levels and increased oxidative metabolite levels (P<.05). In plasma, antioxidant enzyme levels were higher and oxidative metabolite levels were lower in groups D100 and D200 than in group SR (P<.01). In tissues, hepatic and lung GPX levels were higher in groups D100 and D200 than in group SR (P<.001). Renal and thyroid GPX levels were higher in D200 than in group SR (P<.01). Thyroid superoxide dismutase levels were higher in groups D100 and D200 than in group SR (P<.01). Renal, lung, and thyroid catalase levels were higher in group D200 than in group SR (P<.01). Hepatic, renal, and lung advanced oxidation protein products and malondialdehyde levels were lower in groups D100 and D200 than in group SR (P<.01). Hepatic, renal, and lung nitrate/nitrite levels were lower in group D200 than in group SR (P<.05). CONCLUSIONS: Dexmedetomidine preserves the antioxidant enzyme levels and reduces toxic oxidant metabolites. Therefore, it can provide protection from oxidative injury caused by ionizing radiation.

The comparison of the effects of sevoflurane inhalation anesthesia and intravenous propofol anesthesia on oxidative stress in one lung ventilation.

BACKGROUND: The aim of this study is to compare the effects of sevoflurane and propofol on one lung ventilation (OLV) induced ischemia-reperfusion injury (IRI) by determining the blood gas, ischemia-modified albumin (IMA), and malonyldialdehyde (MDA). MATERIAL AND METHODS: Forty-four patients undergoing thoracic surgery with OLV were randomized in two groups (sevoflurane Group S, propofol Group P). Anesthesia was inducted with thiopental and was maintained with 1-2.5% of sevoflurane within the 40/60% of O2/N2O mixture in Group S. In Group P anesthesia was inducted with propofol and was maintained with infusion of propofol and remifentanil. Hemodynamic records and blood samples were obtained before anesthesia induction (t 1), 1 min before two lung ventilation (t 2), 30 min after two lung ventilation (t 3), and postoperative sixth hours (t 4). RESULTS: Heart rate at t 2 and t 3 in Group P was significantly lower than that in Group S. While there were no significant differences in terms of pH and pCO2, pO2 at t 2 and t 3 in Group S was significantly lower than that in Group P. IMA levels at t 4 in Group S were significantly lower than those in Group P. CONCLUSION: Sevoflurane may offer protection against IRI after OLV in thoracic surgery.