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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Acute-Phase Reaction, Aldehydes, Animals, Antioxidants, DNA, Erythropoietin, Gene Expression Regulation, Enzymologic, Guanine, Haptoglobins, Heme Oxygenase (Decyclizing), Heme Oxygenase-1, Hemoglobins, Hemolysis, Inulin, Kidney, Kidney Function Tests, Lipid Peroxidation, Liver, Malondialdehyde, Membrane Proteins, Mice, Mice, Knockout, Oxidative Stress, Phenylhydrazines, Tritium.
user
Does haptoglobin reduce renal oxidative DNA and tissue damage during phenylhydrazine-induced hemolysis? Context: Haptoglobin knockout (Hp-/-) mice are more sensitive to phenylhydrazine-induced hemolysis than Hp+/+ mice. Hemolysis was induced in Hp-/- and Hp+/+ mice using phenylhydrazine. Relative renal tissue damage and function were then assessed. Hp-/- mice had higher basal levels of renal lipid peroxidation, as evidenced by levels of malonaldehyde and 4-hydroxy-2(E)-nonenal (MDA/HNE). After the administration of phenylhydrazine, levels of 8-hydroxyguanine (but not other products of oxidative DNA damage) were significantly elevated in the renal DNA. There was also increased induction of heme oxygenase-1. The more severe renal damage in Hp-/- mice was also evident in the delayed erythropoietin gene expression and poorer renal clearance of 3H-inulin. This reduction in glomerular filtration function in Hp+/+ and Hp-/- mice could be restored to baseline by vasodilators (prazosin or diazoxide), implicating renal vasoconstriction as a major mechanism of acute renal failure during induced hemolysis. Precipitation of hemoglobin in the kidney was not increased in Hp-/- mice.
assistant
Haptoglobin appears to play an important physiological role as an antioxidant, particularly during hemolysis. Final Decision: yes