Oxidative stress can be pathological. Now researchers report that the other end of the redox spectrum, reductive stress, is also pathological. Reductive stress causes pathological heart enlargement and diastolic dysfunction in a mouse model.

But what happens if the redox teeter-totter goes too far down, creating antioxidative stress, also known as reductive stress? Rajasekaran Namakkal-Soorappan, Ph.D., associate professor in the University of Alabama at Birmingham Department of Pathology, and colleagues have found that reductive stress, or RS/AS, is also pathological. This discovery, they say, may have clinical importance in management of heart failure.

They report that RS causes pathological heart enlargement and diastolic dysfunction in a mouse model. This study, published in the journal Antioxidants and Redox Signaling, was led by Namakkal-Soorappan and Pei Ping, Ph.D., David Geffen School of Medicine at the University of California-Los Angeles.

«Antioxidant-based therapeutic approaches for human heart failure should consider a thorough evaluation of antioxidant levels before the treatment,» they said. «Our findings demonstrate that chronic RS is intolerable and adequate to induce heart failure.»

The study used transgenic mice that had upregulated genes for antioxidants in the heart, which increased the amounts of antioxidant proteins and reduced glutathione, creating RS. One mouse line had low upregulation, and one had high upregulation, creating chronic low RS and chronic high RS, respectively, in the hearts of the mice.

The mice with high RS showed pathological heart changes called hypertrophic cardiomyopathy, and had an abnormally high heart ejection fraction and diastolic dysfunction at 6 months of age. Sixty percent of the high-RS mice died by 18 months of age.

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Materials provided by University of Alabama at Birmingham. Original written by Jeff Hansen. Note: Content may be edited for style and length.