Role of oxygen-derived free radicals on rat splanchnic eicosanoid production during acute hemorrhage.
The effect of superoxide dismutase (SOD), an oxygen-derived free radical scavenger, on rat splanchnic eicosanoid synthesis was examined following hemorrhagic shock. Anesthetized male rats were hemorrhaged to 30 mm Hg for 30 minutes (Shock), killed, or treated with the shed blood (Shock plus reperfusion). The Shock plus reperfusion group was treated with saline vehicle or SOD (2500, 5000, 7500, 10,000 or 15,000 U/Kg, i.v.) 15 minutes prior to the reperfusion of the shed blood. The superior mesenteric artery was removed in continuity with the end organ intestine (SV+SI) and perfused in vitro with oxygenated Krebs-Henseleit buffer (3 ml/min at 37 degrees C). Venous effluent was measured for basal release of 6-keto-PGF1 alpha, PGE2 and thromboxane B2 at 15, 30, 60 and 90 minutes of perfusion. The SV+SI compensated for acute shock by increased release of 6-keto-PGF1 alpha (300%) (and not PGE2 or thromboxane B2) which was abolished by reperfusion of the shed blood following shock. Prior treatment of the Shock plus reperfusion group with 7500 U/Kg or more of SOD restored the increased release of SV+SI 6-keto-PGF1 alpha found following shock alone (p less than 0.05). These data provided indirect evidence that ODFRs contributed to endogenous SV+SI regulation of PGI2 synthesis and release during hemorrhagic shock and reperfusion of shed blood.
Myers
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Department of Surgery, University of Texas Southwestern Medical School, Dallas.
Hernandez
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D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000818:Animals; D015232:Dinoprostone / Q000096:biosynthesis; D015777:Eicosanoids / Q000096:biosynthesis*; D005609:Free Radicals; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008638:Mesenteric Arteries / Q000378:metabolism*; D051381:Rats; D012771:Shock, Hemorrhagic / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000494:pharmacology*; D013929:Thromboxane B2 / Q000096:biosynthesis
D015777:Eicosanoids; D005609:Free Radicals; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D013482:Superoxide Dismutase; D015232:Dinoprostone