From the article:
Parkinson’s is due to the loss of dopamine neurons, cells in the region of the brain that controls movement. Oxidative stress, which is a chemical imbalance triggered by sources such as genetic mutations and exposure to environmental toxins, can harm and kill cells. Researchers at the University of North Texas Health Science Center observed in rats' dopamine neurons that testosterone exacerbated damage induced by oxidative stress, acting through a protein called cyclooxygenase 2 (COX2). Blocking the actions of COX2 blocked testosterone’s effects. These data indicate that testosterone may enhance the damage and death in dopamine neurons induced by oxidative stress, explaining the sex differences in the occurrence of Parkinson’s, the researchers wrote