Testosterone therapy could have negative effects, UNTHSC researchers report

Rebecca Cunningham, PhD

"Testosterone can be a good and protective hormone in the brain, or it can be bad," said Rebecca Cunningham, PhD, Assistant Professor of Pharmacology and Neuroscience at UNT Health Science Center. "Oxidative stress is one variable that can determine whether testosterone protects brains cells or damages them."

Oxidative stress occurs when there are more free radicals produced in the body than antioxidants, which can lead to cell damage. Oxidative stress is a key component in many brain disorders, such as Alzheimer's disease and Parkinson's disease. Free radicals are organic molecules responsible for aging and tissue damage.

"Previous studies have shown that 20 to 28 percent of aging men have no response or a negative response to testosterone therapy," Dr. Cunningham said. "About the same percentage of Caucasian men in our study also had adverse effects on cognitive dysfunction and inflammation."

These negative effects were only observed in men with high oxidative stress, said Dr. Cunningham, who will present the research at the Society for Neuroscience annual meeting in November.

The findings could help physicians determine which patients are most likely to benefit from testosterone replacement therapy using a simple blood test for oxidative stress and testosterone levels, Dr. Cunningham said.

Dr. Sid O'Bryant, Associate Professor of Internal Medicine; Dr. James Hall, Professor of Psychiatry and Behavioral Health; Dr. Meharvan Singh, Chairman and Professor of Pharmacology and Neuroscience; and Dr. Robert Barber, Associate Professor of Pharmacology and Neuroscience, also participated in the research.

If you are with the media and need additional information or would like to arrange an interview,
please contact Jeff Carlton, Director of Media Relations, at 817-735-7630.