Sudden Drop in Testosterone Cause Parkinson's Disease-Like Symptoms

A sudden drop in the male sex hormone 'testosterone' may cause symptoms like those seen in people with Parkinson's disease, according to a latest finding.

The study conducted by neurological researchers at Rush University Medical Center reveals that the sudden decrease of testosterone triggers Parkinson's like symptoms in male 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. "We found that the supplementation of testosterone in the form of 5-alpha dihydrotestosterone (DHT) pellets reverses Parkinson's pathology in male mice."

Parkinson's is a chronic and progressive movement disorder. It causes the malfunction and death of crucial nerve cells in the brain. It is the 14the leading cause of death in United States. Every year nearly 60,000 Americans are diagnosed with Parkinson's disease. There are 10 million people worldwide are living with Parkinson's disease and men are one and half times more vulnerable to be effected with Parkinson's, source Parkinson's Disease Foundation.

Testosterone levels in men are closely linked with several diseases. In a healthy male, the level of testosterone is at its maximum during the mid 30s after which, it drops by a percent every year. But in conditions like stress the testosterone levels drop suddenly and this makes the person vulnerable to Parkinson's disease.

According to Pahan, prevention of testosterone reduction in males may be a crucial step to become resistant to Parkinson's disease.

In order to produce effective drugs that will avoid the growth of the disease, it is important to understand how the disease works. One important molecule for both brain and body is nitric oxide. But researchers noticed that production excess nitric oxide within the brain with the help of a inducible nitric oxide synthase, led to the death of neurons. 

"This study has become more fascinating than we thought," said Pahan. "After castration, levels of inducible nitric oxide synthase (iNOS) and nitric oxide go up in the brain dramatically. Interestingly, castration does not cause Parkinson's like symptoms in male mice deficient in iNOS gene, indicating that loss of testosterone causes symptoms via increased nitric oxide production."

The researchers plan to conduct further research to check how to target the testosterone levels in human males to find an effective treatment for the disease.

The study was published in the Journal of Biological Chemistry.