Decreased Levels of Testosterone May Cause Symptoms of Parkinson’s Disease in Men


A new study suggests that a sudden decline in testosterone could be linked to Parkinson’s Disease in men.

Researchers found this link when decreasing the male sex hormone in mice.

“While scientists use different toxins and a number of complex genetic approaches to model Parkinson’s disease in mice, we have found that the sudden drop in the levels of testosterone following castration is sufficient to cause persistent Parkinson’s like pathology and symptoms in male mice,” said Dr. Kalipada Pahan, lead author of the study and the Floyd A. Davis endowed professor of neurology at Rush, via a press release. “We found that the supplementation of testosterone in the form of 5-alpha dihydrotestosterone (DHT) pellets reverses Parkinson’s pathology in male mice.”

“In men, testosterone levels are intimately coupled to many disease processes,” Pahan added, via the release.  Typically, in healthy males, testosterone level is the maximum in the mid-30s, which then drop about one percent each year. However, testosterone levels may dip drastically due to stress or sudden turn of other life events, which may make somebody more vulnerable to Parkinson’s disease. Therefore, preservation of testosterone in males may be an important step to become resistant to Parkinson’s disease.”

Researchers believe that understanding how the disease works has become more fascinating as they determine how to develop effective drugs that can stop the progression of the disease. In particular, many scientists mention Nitric Oxide as an important molecule for the brain and body when functioning against the problem.

“However, when nitric oxide is produced within the brain in excess by a protein called inducible nitric oxide synthase, neurons start dying,” said Pahan, via the release, adding that following castration, levels of inducible nitric oxide synthase (INOS) and nitric oxide go up in the brain dramatically which does not cause Parkinson’s like symptoms in male mice who are deficient of the INOS gene.

Researchers hope further studies might explain why this is happening.

More information regarding the study can be found in the Journal of Biological Chemistry.